Lapidarium notes

What are memories made of?


“There appears to be no single memory store, but instead a diverse taxonomy of memory systems, each with its own special circuitry evolved to package and retrieve that type of memory. Memories are not static entities; over time they shift and migrate between different territories of the brain.

At the top of the taxonomical tree, a split occurs between declarative and non-declarative memories. Declarative memories are those you can state as true or false, such as remembering whether you rode a bicycle to work. Non-declarative memories are those that cannot be described as true or false, such as knowing how to ride a bicycle. A central hub in the declarative memory system is a brain region called the hippocampus. This undulating, twisted structure gets its name from its resemblance to a sea horse. Destruction of the hippocampus, through injury, neurosurgery or the ravages of Alzheimer’s disease, can result in an amnesia so severe that no events experienced after the damage can be remembered. (…)

A popular view is that during sleep your hippocampus “broadcasts” its recently captured memories to the neocortex, which updates your long-term store of past experience and knowledge. Eventually the neocortex is sufficient to support recall without relying on the hippocampus. However, there is evidence that if you need to vividly picture a scene in your mind, this appears to require the hippocampus, no matter how old the memory. We have recently discovered that the hippocampus is not only needed to reimagine the past, but also to imagine the future.

Pattern completion

Studying patients has taught us where memories might be stored, but not what physically constitutes a memory. The answer lies in the multitude of tiny modifiable connections between neuronal cells, the information-processing units of the brain. These cells, with their wispy tree-like protrusions, hang like stars in miniature galaxies and pulse with electrical charge. Thus, your memories are patterns inscribed in the connections between the millions of neurons in your brain. Each memory has its unique pattern of activity, logged in the vast cellular network every time a memory is formed.

It is thought that during recall of past events the original activity pattern in the hippocampus is re-established via a process that is known as “pattern completion”. During this process, the initial activity of the cells is incoherent, but via repeated reactivation the activity pattern is pieced together until the original pattern is complete. Memory retention is helped by the presence of two important molecules in our brain: dopamine and acetylcholine. Both help the neurons improve their ability to lay down memories in their connections. Sometimes, however, the system fails, leaving us unable to bring elements of the past to mind.

Of all the things we need to remember, one of the most essential is where we are. Becoming lost is debilitating and potentially terrifying. Within the hippocampus, and neighbouring brain structures, neurons exist that allow us to map space and find our way through it. “Place cells” provide an internal map of space; “head-direction cell” signal the direction we are facing, similar to an internal compass; and “grid cells” chart out space in a manner akin to latitude and longitude.

For licensed London taxi drivers, it appears that navigating the labyrinth of London’s streets on a daily basis causes the density of grey matter in their posterior hippocampus to increase. Thus, the physical structure of your brain is malleable, depending on what you learn.

With impressive technical advances such as optogenetics, in which light beams excite or silence targeted groups of neurons, scientists are beginning to control memories at an unprecedented level.”

— Hugo Spiers is a neuroscientist and lecturer at the institute of behavioural neuroscience at University College London, What are memories made of?, The Guardian, Jan 14, 2012 (Illustration: Polly Becker)

How and why memories change

“Since the time of the ancient Greeks, people have imagined memories to be a stable form of information that persists reliably. The metaphors for this persistence have changed over time—Plato compared our recollections to impressions in a wax tablet, and the idea of a biological hard drive is popular today—but the basic model has not. Once a memory is formed, we assume that it will stay the same. This, in fact, is why we trust our recollections. They feel like indelible portraits of the past.

None of this is true. In the past decade, scientists have come to realize that our memories are not inert packets of data and they don’t remain constant. Even though every memory feels like an honest representation, that sense of authenticity is the biggest lie of all. (…)

New research is showing that every time we recall an event, the structure of that memory in the brain is altered in light of the present moment, warped by our current feelings and knowledge. (…)

This new model of memory isn’t just a theory—neuroscientists actually have a molecular explanation of how and why memories change. In fact, their definition of memory has broadened to encompass not only the cliché cinematic scenes from childhood but also the persisting mental loops of illnesses like PTSD and addiction—and even pain disorders like neuropathy. Unlike most brain research, the field of memory has actually developed simpler explanations. Whenever the brain wants to retain something, it relies on just a handful of chemicals. Even more startling, an equally small family of compounds could turn out to be a universal eraser of history, a pill that we could take whenever we wanted to forget anything. (…)

How memory is formed

Every memory begins as a changed set of connections among cells in the brain. If you happen to remember this moment—the content of this sentence—it’s because a network of neurons has been altered, woven more tightly together within a vast electrical fabric. This linkage is literal: For a memory to exist, these scattered cells must become more sensitive to the activity of the others, so that if one cell fires, the rest of the circuit lights up as well.

Scientists refer to this process as long-term potentiation, and it involves an intricate cascade of gene activations and protein synthesis that makes it easier for these neurons to pass along their electrical excitement. Sometimes this requires the addition of new receptors at the dendritic end of a neuron, or an increase in the release of the chemical neurotransmitters that nerve cells use to communicate. Neurons will actually sprout new ion channels along their length, allowing them to generate more voltage. Collectively this creation of long-term potentiation is called the consolidation phase, when the circuit of cells representing a memory is first linked together. Regardless of the molecular details, it’s clear that even minor memories require major work. The past has to be wired into your hardware. (…)

What happens after a memory is formed, when we attempt to access it?

The secret was the timing: If new proteins couldn’t be created during the act of remembering, then the original memory ceased to exist. The erasure was also exceedingly specific. (…) They forgot only what they’d been forced to remember while under the influence of the protein inhibitor.

The disappearance of the fear memory suggested that every time we think about the past we are delicately transforming its cellular representation in the brain, changing its underlying neural circuitry. It was a stunning discovery: Memories are not formed and then pristinely maintained, as neuroscientists thought; they are formed and then rebuilt every time they’re accessed. “The brain isn’t interested in having a perfect set of memories about the past,” LeDoux says. “Instead, memory comes with a natural updating mechanism, which is how we make sure that the information taking up valuable space inside our head is still useful. That might make our memories less accurate, but it probably also makes them more relevant to the future.” (…)

[Donald] Lewis had discovered what came to be called memory reconsolidation, the brain’s practice of re-creating memories over and over again. (…)

The science of reconsolidation suggests that the memory is less stable and trustworthy than it appears. Whenever I remember the party, I re-create the memory and alter its map of neural connections. Some details are reinforced—my current hunger makes me focus on the ice cream—while others get erased, like the face of a friend whose name I can no longer conjure. The memory is less like a movie, a permanent emulsion of chemicals on celluloid, and more like a play—subtly different each time it’s performed. In my brain, a network of cells is constantly being reconsolidated, rewritten, remade. That two-letter prefix changes everything. (…)

Once you start questioning the reality of memory, things fall apart pretty quickly. So many of our assumptions about the human mind—what it is, why it breaks, and how it can be healed—are rooted in a mistaken belief about how experience is stored in the brain. (According to a recent survey, 63 percent of Americans believe that human memory “works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.”) We want the past to persist, because the past gives us permanence. It tells us who we are and where we belong. But what if your most cherished recollections are also the most ephemeral thing in your head? (…)

Reconsolidation provides a mechanistic explanation for these errors. It’s why eyewitness testimony shouldn’t be trusted (even though it’s central to our justice system), why every memoir should be classified as fiction, and why it’s so disturbingly easy to implant false recollections. (The psychologist Elizabeth Loftus has repeatedly demonstrated that nearly a third of subjects can be tricked into claiming a made-up memory as their own. It takes only a single exposure to a new fiction for it to be reconsolidated as fact.) (…)

When we experience a traumatic event, it gets remembered in two separate ways. The first memory is the event itself, that cinematic scene we can replay at will. The second memory, however, consists entirely of the emotion, the negative feelings triggered by what happened. Every memory is actually kept in many different parts of the brain. Memories of negative emotions, for instance, are stored in the amygdala, an almond-shaped area in the center of the brain. (Patients who have suffered damage to the amygdala are incapable of remembering fear.) By contrast, all the relevant details that comprise the scene are kept in various sensory areas—visual elements in the visual cortex, auditory elements in the auditory cortex, and so on. That filing system means that different aspects can be influenced independently by reconsolidation.

The larger lesson is that because our memories are formed by the act of remembering them, controlling the conditions under which they are recalled can actually change their content. (…)

The chemistry of the brain is in constant flux, with the typical neural protein lasting anywhere from two weeks to a few months before it breaks down or gets reabsorbed. How then do some of our memories seem to last forever? It’s as if they are sturdier than the mind itself. Scientists have narrowed down the list of molecules that seem essential to the creation of long-term memory—sea slugs and mice without these compounds are total amnesiacs—but until recently nobody knew how they worked. (…)

A form of protein kinase C called PKMzeta hangs around synapses, the junctions where neurons connect, for an unusually long time. (…) What does PKMzeta do? The molecule’s crucial trick is that it increases the density of a particular type of sensor called an AMPA receptor on the outside of a neuron. It’s an ion channel, a gateway to the interior of a cell that, when opened, makes it easier for adjacent cells to excite one another. (While neurons are normally shy strangers, struggling to interact, PKMzeta turns them into intimate friends, happy to exchange all sorts of incidental information.) This process requires constant upkeep—every long-term memory is always on the verge of vanishing. As a result, even a brief interruption of PKMzeta activity can dismantle the function of a steadfast circuit. (…)

Because of the compartmentalization of memory in the brain—the storage of different aspects of a memory in different areas—the careful application of PKMzeta synthesis inhibitors and other chemicals that interfere with reconsolidation should allow scientists to selectively delete aspects of a memory. (…)

The astonishing power of PKMzeta forces us to redefine human memory. While we typically think of memories as those facts and events from the past that stick in the brain, Sacktor’s research suggests that memory is actually much bigger and stranger than that. (…)

Being able to control memory doesn’t simply give us admin access to our brains. It gives us the power to shape nearly every aspect of our lives. There’s something terrifying about this. Long ago, humans accepted the uncontrollable nature of memory; we can’t choose what to remember or forget. But now it appears that we’ll soon gain the ability to alter our sense of the past. (…)

The fact is we already tweak our memories—we just do it badly. Reconsolidation constantly alters our recollections, as we rehearse nostalgias and suppress pain. We repeat stories until they’re stale, rewrite history in favor of the winners, and tamp down our sorrows with whiskey. “Once people realize how memory actually works, a lot of these beliefs that memory shouldn’t be changed will seem a little ridiculous,” Nader says. “Anything can change memory. This technology isn’t new. It’s just a better version of an existing biological process.” (…)

— Jonah Lehrer, American author and journalist, The Forgetting Pill Erases Painful Memories Forever, Wired Magazine, Feb 17, 2012. (Third illustration: Dwight Eschliman)

“You could double the number of synaptic connections in a very simple neurocircuit as a result of experience and learning. The reason for that was that long-term memory alters the expression of genes in nerve cells, which is the cause of the growth of new synaptic connections. When you see that at the cellular level, you realize that the brain can change because of experience. It gives you a different feeling about how nature and nurture interact. They are not separate processes.”

— Eric R. Kandel, American neuropsychiatrist, Nobel Prize laureate, A Quest to Understand How Memory Works, NYT, March 5, 2012

Prof. Eric Kandel: We Are What We Remember - Memory and Biology

— Eric R. Kandel, American neuropsychiatrist, Nobel Prize laureate, We Are What We Remember: Memory and Biology, FORA.tv, Prohansky Auditorium New York, NY, Mar 28.2011

See also:

☞ Eric R. Kandel, The Biology of Memory: A Forty-Year Perspective (pdf), Department of Neuroscience, Columbia University, New York, 2009
☞ Eric R. Kandel, A Biological Basis for the Unconscious?, Eric Kandel: “I want to know where the id, the ego, and the super-ego are located in the brain” | Big Think video Apr 1, 2012.
☞ Memory tag on Lapidarium notes

The Human Brain Project ☞ reconstructing the brain piece by piece and building a virtual brain in a supercomputer

       
                                 (Click image to go to the The Human Brain Project)

“The brain, with its billions of interconnected neurons, is without any doubt the most complex organ in the body and it will be a long time before we understand all its mysteries. The Human Brain Project proposes a completely new approach. The project is integrating everything we know about the brain into computer models and using these models to simulate the actual working of the brain. Ultimately, it will attempt to simulate the complete human brain. The models built by the project will cover all the different levels of brain organisation – from individual neurons through to the complete cortex. The goal is to bring about a revolution in neuroscience and medicine and to derive new information technologies directly from the architecture of the brain.” — Human Brain Project - Introduction

The Blue Brain Project is an attempt to create a synthetic brain by reverse-engineering the mammalian brain down to the molecular level.

The aim of the project, founded in May 2005 by the Brain and Mind Institute of the École Polytechnique Fédérale de Lausanne (Switzerland) is to study the brain’s architectural and functional principles. The project is headed by the Institute’s director, Henry Markram. Using a Blue Gene supercomputer running Michael Hines’s NEURON software, the simulation does not consist simply of an artificial neural network, but involves a biologically realistic model of neurons. It is hoped that it will eventually shed light on the nature of consciousness. (Wiki)

Henry Markram: Supercomputing the brain’s secrets



Henry Markram, Ph.D., Director of the Blue Brain Project at École Polytechnique Fédérale de Lausanne, says the mysteries of the mind can be solved — soon. Mental illness, memory, perception: they’re made of neurons and electric signals, and he plans to find them with a supercomputer that models all the brain’s 100,000,000,000,000 synapses.

— Henry Markram builds a brain in a supercomputer, TED.com, July 2009

Henry Markram: Simulating the Brain — The Next Decisive Years

Henry Markram speaks at the International Supercomputing Conference 26.06.2011.

10 Year Documentary To Follow Bluebrain Project

Bluebrain | Year One from Couple 3 Films.

Noah Hutton (…) has recently released a mini-documentary on the first year of IBM’s Bluebrain Project. (…) There are reasons to be hopeful that Markram and others in the field will make reasonable progress in modelling the brain by 2020. As he points out in the video, modeling a single neuron used to be a PhD thesis in and of itself. Now, he can create thousands at the push of a button.  As Markram mentions, we don’t have a complete understanding of how many drugs or diseases affect the brain. Nor do we fully understand the nature of memories. A brain simulator could be profoundly helpful as we care for our aging minds. Those minds have at least a decade to wait before we know if Markram and the BBP will be successful in transforming the field of neurology into a computer problem.”

— Aaron Saenz, 10 Year Documentary To Follow Bluebrain Project, Singularity Hub, Feb 12, 2011

See also:

☞ Human Connectome Project ☞ understanding how different parts of the brain communicate to each other
☞ New evidence for innate knowledge. Neurons make connections independently of a subject’s experience, Ecole Polytechnique
☞ Henry Markram and the Human Brain Project are in talks with EU for $1.61 billion to build a human brain within decade, May 18, 2011
☞ Mark Changizi, Later Terminator: We’re Nowhere Near Artificial Brains, Discover Magazine, Nov 16, 2011
☞ David Eagleman, Henry Markram, Will We Ever Understand the Brain?, California Academy of Sciences San Francisco, CA, Fora.tv video, Nov 2, 2011
☞ Allan Jones: A map of the brain, TED.com, July 2011.
☞ Neuroscience tag on Lapidarium notes

Galileo and the relationship between the humanities and the sciences

“Ever since Galileo, science has been strongly committed to the unification of theories from different disciplines. It cannot accept that the right explanations of human activities must be logically incompatible with the rest of science, or even just independent of it. If science were prepared to settle for less than unification, the difficulty of reconciling quantum mechanics and general relativity wouldn’t be the biggest problem in physics. Biology would not accept the gene as real until it was shown to have a physical structure — DNA — that could do the work geneticists assigned to the gene. For exactly the same reason science can’t accept interpretation as providing knowledge of human affairs if it can’t at least in principle be absorbed into, perhaps even reduced to, neuroscience.

That’s the job of neurophilosophy.

This problem, that thoughts about ourselves or anything else for that matters couldn’t be physical, was for a long time purely academic. Scientists had enough on their plates for 400 years just showing how physical processes bring about chemical processes, and through them biological ones. But now neuroscientists are learning how chemical and biological events bring about the brain processes that actually produce everything the body does, including speech and all other actions.

Research — including Nobel-prize winning neurogenomics and fMRI (functional magnetic resonance imaging) — has revealed how bad interpretation’s explanations of our actions are. And there are clever psychophysical experiences that show us that introspection’s insistence that interpretation really does explain our actions is not to be trusted.

These findings cannot be reconciled with explanation by interpretation. The problem they raise for the humanities can no longer be postponed. Must science write off interpretation the way it wrote off phlogiston theory — a nice try but wrong? Increasingly, the answer that neuroscience gives to this question is “afraid so.”

Few people are prepared to treat history, (auto-) biography and the human sciences like folklore. The reason is obvious. The narratives of history, the humanities and literature provide us with the feeling that we understand what they seek to explain. At their best they also trigger emotions we prize as marks of great art.

But that feeling of understanding, that psychological relief from the itch of curiosity, is not the same thing as knowledge. It is not even a mark of it, as children’s bedtime stories reveal. If the humanities and history provide only feeling (ones explained by neuroscience), that will not be enough to defend their claims to knowledge.

The only solution to the problem faced by the humanities, history and (auto) biography, is to show that interpretation can somehow be grounded in neuroscience. That is job No. 1 for neurophilosophy. And the odds are against it. If this project doesn’t work out, science will have to face plan B: treating the humanities the way we treat the arts, indispensable parts of human experience but not to be mistaken for contributions to knowledge.”

— Alex Rosenberg, American philosopher, and the R. Taylor Cole Professor of Philosophy at Duke University, Bodies in Motion: An Exchange, NYT, Nov 6, 2011.

Do the humanities need to be defended from hard science?

“As the mathematician and physicist Mark A. Peterson has shown in his new book, “Galileo’s Muse: Renaissance Arts and Mathematics,” Galileo’s love for the arts profoundly shaped his thinking, and in many ways helped paved the way for his scientific discoveries. An early biography of Galileo by his contemporary Niccolò Gherardini points out that, “He was most expert in all the sciences and arts, as if he were professor of them. He took extraordinary delights in music, painting, and poetry.” For its part, Peterson takes great delight in demonstrating how his immersion in these arts informed his scientific discoveries, and how art and literature prior to Galileo often planted the seeds of scientific progress to come. (…)

Clearly Galileo was an extraordinary man, and a crucial aspect of what made him that man was the intellectual world he was immersed in. This world included mathematics, of course, but it was also full of arts and literature, of philosophy and theology. Peterson argues forcefully, for instance, that Galileo’s mastery of the techniques involved in creating and thinking about perspective in painting could well have influenced his thinking about the relativity of motion, since both require comprehending the importance of multiple points of view. (…)

The idea that the perception of movement depends on one’s point of view also has forebears in proto-scientific thinkers who are far less suitable candidates for the appealing story of how common sense suddenly toppled a 2000-year old tradition to usher modern science into the world. Take the poet, philosopher and theologian Giordano Bruno, who seldom engaged in experimentation and who, 30 years before Galileo’s own trial, refused to recant the beliefs that led him to be burned at the stake, beliefs that included the infinity of the universe and the multiplicity of worlds. (…)

Galileo’s insight into the nature of motion was not merely the epiphany of everyday experience that brushed away the fog of scholastic dogma; it was a logical consequence of a long history of engagements with an intellectual tradition that encompassed a multitude of forms of knowledge. That force is not required for an object to stay in motion goes hand in hand with the realization that motion and rest are not absolute terms, but can only be defined relative to what would later be called inertial frames. And this realization owes as much to a literary, philosophical and theological inquiry as it does to pure observation.

Professor Rosenberg uses his brief history of science to ground the argument that neuroscience threatens the humanities, and the only thing that can save them is a neurophilosophy that reconciles brain processes and interpretation. “If this project doesn’t work out,” he writes, “science and the humanities will have to face plan B: treating the humanities the way we treat the arts, indispensable parts of human experience but not to be mistaken for contributions to knowledge.”

But if this is true, should we not then ask what neuroscience could possible contribute to the very debate we are engaged in at this moment? What would we learn about the truth-value of Professor Rosenberg’s claims or mine if we had even the very best neurological data at our disposal? That our respective pleasure centers light up as we each strike blows for our preferred position? That might well be of interest, but it hardly bears on the issue at hand, namely, the evaluation of evidence — historical or experimental — underlying a claim about knowledge. That evaluation must be interpretative. The only way to dispense with interpretation is to dispense with evidence, and with it knowledge altogether.”

— William Egginton is the Andrew W. Mellon Professor in the Humanities and Chair of the Department of German and Romance Languages and Literatures at the John Hopkins University, Bodies in Motion: An Exchange, NYT, Nov 6, 2011.

Concentration. When Our Neurons Remain Silent So That Our Performances May Improve

(Whenever we look carefully for an object around us, the parts of the brain that are coloured in red are activated; but, at the same time, those in blue must deactivate themselves. (Credit: Image courtesy of INSERM (Institut national de la santé et de la recherche médicale)

“To be able to focus on the world, we need to turn a part of ourselves off for a short while, and this is precisely what our brain does. (…) A team of researchers from Inserm, led by Jean Philippe Lachaux and Karim Jerbi (Lyon Neuroscience Research Centre), has just demonstrated that a network of specific neurons, referred to as “default-mode network” works on a permanent basis even when we are doing nothing. (…)

They demonstrate more specifically that when we need to concentrate, this network disrupts the activation of other specialized neurons when it is not deactivated enough. (…)

When we focus on the things around us, certain parts of the brain are activated: this network, well known to neurobiologists, is called the attention network. Other parts of the brain, however, cease their activity at the same time, as if they generally prevented our attention from being focused on the outside world. These parts of the brain form a network that is extensively studied in neurobiology, and commonly known as the “default-mode network,” because, for a long time, it was believed that it activated itself when the brain had nothing in particular to do. This interpretation was refined through ten years of neuroimaging research that concluded by associating this mysterious network (“the brain’s dark energy” as it was called by one of its discoverers, Marcus Raichle) with a host of intimate and private phenomena of our mental life: self-perception, recollections, imagination, thoughts… (…)

[Researchers] has just revealed how this network interferes with our ability to pay attention, by assessing the activity of the human brain’s default-mode network neurons on a millisecond scale for the first time ever. (…)

The results unambiguously illustrate that whenever we look for an object in the area around us, the neurons of this default-mode network stop their activity. Yet, this interruption only lasts for the amount of time required to find the object: in less than a tenth of a second, after the object has been found, the default-mode network resumes its activity as before. And if our default-mode network is not sufficiently deactivated, then we will need more time to find the object.

These results show that there is fierce competition for our attentional resources inside our brain which, when they are not used to actively analyse our sensorial environment, are instantaneously redirected towards more internal mental processes. The brain hates emptiness and never stays idle, even for a tenth of a second.”

— When Our Neurons Remain Silent So That Our Performances May Improve, ScienceDaily, Nov. 3, 2011.

See also:

☞ Transient Suppression of Broadband Gamma Power in the Default-Mode Network Is Correlated with Task Complexity and Subject Performance, The Journal of Neuroscience, 12 Oct 2011.

“Task performance is associated with increased brain metabolism but also with prominent deactivation in specific brain structures known as default-mode network (DMN). (…)

We found that all DMN areas displayed transient suppressions of broadband gamma (60–140 Hz) power during performance of a visual search task and, critically, we show for the first time that the millisecond range duration and extent of the transient gamma suppressions are correlated with task complexity and subject performance. In addition, trial-by-trial correlations revealed that spatially distributed gamma power increases and decreases formed distinct anticorrelated large-scale networks.

Beyond unraveling the electrophysiological basis of DMN dynamics, our results suggest that, rather than indicating a mere switch to a global exteroceptive mode, DMN deactivation encodes the extent and efficiency of our engagement with the external world. (…)”

Fear, Greed, and Financial Crises: A Cognitive Neurosciences Perspective

                           
                                                                           NYT

“Far be it from me to say that we ever shall have the means of measuring directly the feelings of the human heart. A unit of pleasure or of pain is difficult even to conceive; but it is the amount of these feelings which is continually prompting us to buying and selling, borrowing and lending, labouring and resting, producing and consuming; and it is from the quantitative effects of the feelings that we must estimate their comparative amounts.”

— William Stanley Jevons, British economist, in 1871.

Abstract: 

“Historical accounts of financial crises suggest that fear and greed are the common denominators of these disruptive events: periods of unchecked greed eventually lead to excessive leverage and unsustainable asset-price levels, and the inevitable collapse results in unbridled fear, which must subside before any recovery is possible. The cognitive neurosciences may provide some new insights into this boom/bust pattern through a deeper understanding of the dynamics of emotion and human behavior.

In this chapter, I describe some recent research from the neurosciences literature on fear and reward learning, mirror neurons, theory of mind, and the link between emotion and rational behavior. By exploring the neuroscientific basis of cognition and behavior, we may be able to identify more fundamental drivers of financial crises, and improve our models and methods for dealing with them.”

To read full Andrew W. Lo’s research paper click Fear, Greed, and Financial Crises: A Cognitive Neurosciences Perspective (pdf) pages: 50, MIT Sloan School of Management; MIT CSAIL; National Bureau of Economic Research (NBER), Oct 13, 2011.

The ‘rich club’ that rules your brain

        
The connectome with its 12 “rich club” hubs. Green means fewer connections, red means more connections (Image: Martijn van den Heuvel/University Medical Center in Utrecht)

“Not all brain regions are created equal – instead, a “rich club” of 12 well-connected hubs orchestrates everything that goes on between your ears. This elite cabal could be what gives us consciousness, and might be involved in disorders such as schizophrenia and Alzheimer’s disease.

As part of an ongoing effort to map the human “connectome” – the full network of connections in the brain – Martijn van den Heuvel of the University Medical Center in Utrecht, the Netherlands, and Olaf Sporns of Indiana University Bloomington scanned the brains of 21 people as they rested for 30 minutes.

The researchers used a technique called diffusion tensor imaging to track the movements of water through 82 separate areas of the brain and their interconnecting neurons. They found 12 areas of the brain had significantly more connections than all the others, both to other regions and among themselves.

“These 12 regions have twice the connections of other brain regions, and they’re more strongly connected to each other than to other regions,” says Van den Heuvel. “If we wanted to look for consciousness in the brain, I would bet on it turning out to be this rich club,” he adds.

Members of the elite

The elite group consists of six pairs of identical regions, with one of each pair in each hemisphere of the brain. Each member is known to accept only preprocessed, high-order information, rather than raw incoming sensory data.

Best connected of all is the precuneus, an area at the back of the brain. Van den Heuvel says its function is not well understood, but thinks that it acts as an “integrator region” collating high-level information from all over the brain.

Another prominent hub is the superior frontal cortex, which plans actions in response to events and governs where you should focus your attention. The superior parietal cortex – the third hub – is linked to the visual cortex and registers where different objects in your immediate vicinity are.

To bring memory into the equation, the hippocampus is another hub – that’s where memories are processed, stored and consolidated. The fifth member of the club is the thalamus, which, among other things, interlinks visual processes; the last member, the putamen, coordinates movement.

Together the hubs enable the brain to constantly assess, prioritise and filter incoming information, and then puts it all together to make decisions about what to do next.

This network makes the way the brain functions more robust overall, but it could also leave the entire system vulnerable to breakdown if key hubs are damaged or disabled, says Van den Heuvel.

Downfall of the rich

After mapping the connections, Van den Heuvel’s team manipulated the data to see what might happen if parts of the rich club were damaged. The simulated brain lost three times as much function if the elite hubs were taken out than if random parts of the brain were lost.

“If [one of these] regions goes down, it can take the others down too, just like when banks failed in the global economic crisis,” says Van den Heuvel. (…)

“The human brain is extraordinarily complex, yet it works efficiently, and a major challenge has been to discover principles of brain wiring and organisation that explain this,” says Randy Buckner, a neuroscientist at Harvard University.

“What Van den Heuvel and Sporns show is that some regions of the brain are embedded in densely connected networks – so-called rich clubs – that may act together as a functional unit,” says Buckner. “Such an organisation might help explain how complex networks of brain regions can work together efficiently.”“

— Andy Coghlan, The ‘rich club’ that rules your brain, New Scientist, 2 Nov 2011

See also:

☞ Human Connectome Project - understanding how different parts of the brain communicate to each other
☞ Revealed – the capitalist network that runs the world, New Scientist, Oct 19, 2011

Iain McGilchrist on The Divided Brain and the Making of the Western World

“Just as the human body represents a whole museum of organs, with a long evolutionary history behind them, so we should expect the mind to be organized in a similar way. (…) We receive along with our body a highly differentiated brain which brings with it its entire history, and when it becomes creative it creates out of this history – out of the history of mankind (…) that age-old natural history which has been transmitted in living form since the remotest times, namely the history of the brain structure.”

— Carl Jung cited in The Master and His Emissary, Yale University Press, 2009, p.8.

Renowned psychiatrist and writer Iain McGilchrist explains how the ‘divided brain’ has profoundly altered human behaviour, culture and society. He draws on a vast body of recent experimental brain research to reveal that the differences between the brain’s two hemispheres are profound.

The left hemisphere is detail-oriented, prefers mechanisms to living things, and is inclined to self-interest. It misunderstands whatever is not explicit, lacks empathy and is unreasonably certain of itself, whereas the right hemisphere has greater breadth, flexibility and generosity, but lacks certainty.

It is vital that the two hemispheres work together, but McGilchrist argues that the left hemisphere is increasingly taking precedence in the modern world, resulting in a society where a rigid and bureaucratic obsession with structure and self-interest hold sway.

— RSA, 17th Nov 2010

“Iain McGilchrist points out that the idea that “reason [is] in the left hemisphere and something like creativity and emotion [are] in the right hemisphere” is an unhelpful misconception. He states that “every single brain function is carried out by both hemispheres. Reason and emotion and imagination depend on the coming together of what both hemispheres contribute.” Nevertheless he does see an obvious dichotomy, and asks himself: “if the brain is all about making connections, why is it that it’s evolved with this whopping divide down the middle?”

— Natasha Mitchell, “The Master and his Emissary: the divided brain and the reshaping of Western civilisation”, 19 June 2010

“The author holds instead that each of the hemispheres of the brain has a different “take” on the world or produces a different “version” of the world, though under normal circumstances these work together. This, he says, is basically to do with attention. He illustrates this with the case of chicks which use the eye connected to the left hemisphere to attend to the fine detail of picking seeds from amongst grit, whilst the other eye attends to the broader threat from predators. According to the author, “The left hemisphere has its own agenda, to manipulate and use the world”; its world view is essentially that of a mechanism. The right has a broader outlook, “has no preconceptions, and simply looks out to the world for whatever might be. In other words it does not have any allegiance to any particular set of values.”

— Staff, “Two worlds of the left and right brain (audio podcast)”, BBC Radio 4, 14 November 2009

McGilchrist explains this more fully in a later interview for ABC Radio National’s All in the Mind programme, stating: “The right hemisphere sees a great deal, but in order to refine it, and to make sense of it in certain ways—-in order to be able to use what it understands of the world and to be able to manipulate the world—-it needs to delegate the job of simplifying it and turning it into a usable form to another part of the brain” [the left hemisphere]. Though he sees this as an essential “double act”, McGilchrist points to the problem that the left hemisphere has a “narrow, decontextualised and theoretically based model of the world which is self consistent and is therefore quite powerful” and to the problem of the left hemisphere’s lack of awareness of its own shortcomings; whilst in contrast, the right hemisphere is aware that it is in a symbiotic relationship.”

How the brain has shaped our world

“The author describes the evolution of Western culture, as influenced by hemispheric brain functioning, from the ancient world, through the Renaissance and Reformation; the Enlightenment; Romanticism and Industrial Revolution; to the modern and postmodern worlds which, to our detriment, are becoming increasingly dominated by the left brain. According to McGilchrist, interviewed for ABC Radio National’s All in the Mind programme, rather than seeking to explain the social and cultural changes and structure of civilisation in terms of the brain — which would be reductionist — he is pointing to a wider, more inclusive perspective and greater reality in which there are two competing ways of thinking and being, and that in modern Western society we appear increasingly to be able to only entertain one viewpoint: that of the left hemisphere.

The author argues that the brain and the mind do not simply experience the world, but that the world we experience is a product or meeting of that which is outside us with our mind. The outcome, the nature of this world, is thus dependent upon “which mode of attention we bring to bear on the world”

McGilchrist sees an occasional flowering of “the best of the right hemisphere and the best of the left hemisphere working together” in our history: as witnessed in Athens in the 6th century by activity in the humanities and in science and in ancient Rome during the Augustan era. However, he also sees that as time passes, the left hemisphere once again comes to dominate affairs and things slide back into “a more theoretical and conceptualised abstracted bureaucratic sort of view of the world.” According to McGilchrist, the cooperative use of both left and right hemispheres diminished and became imbalanced in favour of the left in the time of the classical Greek philosophers Parmenides and Plato and in the late classical Roman era. This cooperation and openness were regained during the Renaissance 1,000 years later which brought “sudden efflorescence of creative life in the sciences and the arts”. However, with the Reformation, the early Enlightenment, and what has followed as rationalism has arisen, our world has once again become increasingly rigid, simplified and rule-bound.

Looking at more recent Western history, McGilchrist sees in the Industrial Revolution that for the first time artefacts were being made “very much to the way the left hemisphere sees the world — simple solids that are regular, repeated, not individual in the way that things that are made by hand are” and that a transformation of the environment in a similar vein followed on from that; that what was perceived inwardly was projected outwardly on a mass scale. The author argues that the scientific materialism which developed in the 19th century is still with us, at least in the biological sciences, though he sees physics as having moved on.

McGilchrist does not see modernism and postmodernism as being in opposition to this, but also “symptomatic of a shift towards the left hemisphere’s conception of the world”, taking the idea that there is no absolute truth and turning that into “there is no truth at all”, and he finds some of the movements’ works of art “symptomatic of people whose right hemisphere is not working very well.” McGilchrist cites the American psychologist Louis Sass, author of Madness and Modernism, pointing out that Sass “draws extensive parallels between the phenomena of modernism and postmodernism and of schizophrenia”, with things taken out of context and fragmented.”

— The Master and His Emissary, Wiki

The Master and His Emissary

“Whatever the relationship between consciousness and the brain – unless the brain plays no role in bringing the world as we experience it into being, a position that must have few adherents – its structure has to be significant. It might even give us clues to understanding the structure of the world it mediates, the world we know. So, to ask a very simple question, why is the brain so clearly and profoundly divided? Why, for that matter, are the two cerebral hemispheres asymmetrical? Do they really differ in any important sense? If so, in what way? (…)

Enthusiasm for finding the key to hemisphere differences has waned, and it is no longer respectable for a neuroscientist to hypothesise on the subject. (…)

These beliefs could, without much violence to the facts, be characterised as versions of the idea that the left hemisphere is somehow gritty, rational, realistic but dull, and the right hemisphere airy-fairy and impressionistic, but creative and exciting; a formulation reminiscent of Sellar and Yeatman’s immortal distinction (in their parody of English history teaching, 1066 and All That) between the Roundheads – ‘Right and Repulsive’ – and the Cavaliers – ‘Wrong but Wromantic’. In reality, both hemispheres are crucially involved in reason, just as they are in language; both hemispheres play their part in creativity. Perhaps the most absurd of these popular misconceptions is that the left hemisphere, hard-nosed and logical, is somehow male, and the right hemisphere, dreamy and sensitive, is somehow female. (…)

V. S. Ramachandran, another well-known and highly regarded neuroscientist, accepts that the issue of hemisphere difference has been traduced, but concludes: ‘The existence of such a pop culture shouldn’t cloud the main issue – the notion that the two hemispheres may indeed be specialised for different functions. (…)

I believe there is, literally, a world of difference between the hemispheres. Understanding quite what that is has involved a journey through many apparently unrelated areas: not just neurology and psychology, but philosophy, literature and the arts, and even, to some extent, archaeology and anthropology. (…)

I have come to believe that the cerebral hemispheres differ in ways that have meaning. There is a plethora of well-substantiated findings that indicate that there are consistent differences – neuropsychological, anatomical, physiological and chemical, amongst others – between the hemispheres. But when I talk of ‘meaning’, it is not just that I believe there to be a coherent pattern to these differences. That is a necessary first step. I would go further, however, and suggest that such a coherent pattern of differences helps to explain aspects of human experience, and therefore means something in terms of our lives, and even helps explain the trajectory of our common lives in the Western world.

My thesis is that for us as human beings there are two fundamentally opposed realities, two different modes of experience; that each is of ultimate importance in bringing about the recognisably human world; and that their difference is rooted in the bihemispheric structure of the brain. It follows that the hemispheres need to co-operate, but I believe they are in fact involved in a sort of power struggle, and that this explains many aspects of contemporary Western culture. (…)

The brain has evolved, like the body in which it sits, and is in the process of evolving. But the evolution of the brain is different from the evolution of the body. In the brain, unlike in most other human organs, later developments do not so much replace earlier ones as add to, and build on top of, them. Thus the cortex, the outer shell that mediates most so-called higher functions of the brain, and certainly those of which we are conscious, arose out of the underlying subcortical structures which are concerned with biological regulation at an unconscious level; and the frontal lobes, the most recently evolved part of the neocortex, which occupy a much bigger part of the brain in humans than in our animal relatives, and which grow forwards from and ‘on top of ’ the rest of the cortex, mediate most of the sophisticated activities that mark us out as human – planning, decision making, perspective taking, self-control, and so on. In other words, the structure of the brain reflects its history: as an evolving dynamic system, in which one part evolves out of, and in response to, another. (…)

There is after all coherence to the way in which the correlates of our experience are grouped and organised in the brain, and we can see these ‘functions’ forming intelligible wholes, corresponding to areas of experience, and see how they relate to one another at the brain level, this casts some light on the structure and experience of our mental world. In this sense the brain is – in fact it has to be – a metaphor of the world. (…)

I believe that there are two fundamentally opposed realities rooted in the bihemispheric structure of the brain. But the relationship between them is no more symmetrical than that of the chambers of the heart – in fact, less so; more like that of the artist to the critic, or a king to his counsellor.

There is a story in Nietzsche that goes something like this. There was once a wise spiritual master, who was the ruler of a small but prosperous domain, and who was known for his selfless devotion to his people. As his people flourished and grew in number, the bounds of this small domain spread; and with it the need to trust implicitly the emissaries he sent to ensure the safety of its ever more distant parts. It was not just that it was impossible for him personally to order all that needed to be dealt with: as he wisely saw, he needed to keep his distance from, and remain ignorant of, such concerns. And so he nurtured and trained carefully his emissaries, in order that they could be trusted. Eventually, however, his cleverest and most ambitious vizier, the one he most trusted to do his work, began to see himself as the master, and used his position to advance his own wealth and influence. He saw his master’s temperance and forbearance as weakness, not wisdom, and on his missions on the master’s behalf, adopted his mantle as his own – the emissary became contemptuous of his master. And so it came about that the master was usurped, the people were duped, the domain became a tyranny; and eventually it collapsed in ruins.

The meaning of this story is as old as humanity, and resonates far from the sphere of political history. I believe, in fact, that it helps us understand something taking place inside ourselves, inside our very brains, and played out in the cultural history of the West, particularly over the last 500 years or so. (…)

I hold that, like the Master and his emissary in the story, though the cerebral hemispheres should co-operate, they have for some time been in a state of conflict. The subsequent battles between them are recorded in the history of philosophy, and played out in the seismic shifts that characterise the history of Western culture. At present the domain – our civilisation – finds itself in the hands of the vizier, who, however gifted, is effectively an ambitious regional bureaucrat with his own interests at heart. Meanwhile the Master, the one whose wisdom gave the people peace and security, is led away in chains. The Master is betrayed by his emissary.”

— Iain McGilchrist, psychiatrist and writer, The Master and His Emissary, Yale University Press, 2009 Illustrations: 1), 2) Shalmor Avnon Amichay/Y&R Interactive

Iain McGilchrist: The Divided Brain | RSA animated

— RSA, 17th Nov 2010

See also:

☞ Iain McGilchrist, The Battle Between the Brain’s Left and Right Hemispheres, WSJ.com, Jan 2, 2010
☞ David Eagleman on how we constructs reality, time perception, and The Secret Lives of the Brain
☞ Dean Buonomano on ‘Brain Bugs’ - Cognitive Flaws That ‘Shape Our Lives’
☞ Timothy D. Wilson on The Social Psychological Narrative: ‘It’s not the objective environment that influences people, but their constructs of the world’
☞ Mind and Brain tag on Lapidarium notes

Time and the Brain. Eagleman: ‘Time is not just as a neuronal computation—a matter for biological clocks—but as a window on the movements of the mind’

                               

“Instead of reality being passively recorded by the brain, it is actively constructed by it.”

— David Eagleman, Incognito: The Secret Lives of the Brain, Pantheon Books, 2011

“Clocks offer at best a convenient fiction, [David Eagleman] says. They imply that time ticks steadily, predictably forward, when our experience shows that it often does the opposite: it stretches and compresses, skips a beat and doubles back.”

Just how many clocks we contain still isn’t clear. The most recent neuroscience papers make the brain sound like a Victorian attic, full of odd, vaguely labelled objects ticking away in every corner. The circadian clock, which tracks the cycle of day and night, lurks in the suprachiasmatic nucleus, in the hypothalamus. The cerebellum, which governs muscle movements, may control timing on the order of a few seconds or minutes. The basal ganglia and various parts of the cortex have all been nominated as timekeepers, though there’s some disagreement on the details.

The standard model, proposed by the late Columbia psychologist John Gibbon in the nineteen-seventies, holds that the brain has “pacemaker” neurons that release steady pulses of neurotransmitters. More recently, at Duke, the neuroscientist Warren Meck has suggested that timing is governed by groups of neurons that oscillate at different frequencies. At U.C.L.A., Dean Buonomano believes that areas throughout the brain function as clocks, their tissue ticking with neural networks that change in predictable patterns. “Imagine a skyscraper at night,” he told me. “Some people on the top floor work till midnight, while some on the lower floors may go to bed early. If you studied the patterns long enough, you could tell the time just by looking at which lights are on.”

Time isn’t like the other senses, Eagleman says. Sight, smell, touch, taste, and hearing are relatively easy to isolate in the brain. They have discrete functions that rarely overlap: it’s hard to describe the taste of a sound, the color of a smell, or the scent of a feeling. (Unless, of course, you have synesthesia—another of Eagleman’s obsessions.) But a sense of time is threaded through everything we perceive. It’s there in the length of a song, the persistence of a scent, the flash of a light bulb. “There’s always an impulse toward phrenology in neuroscience—toward saying, ‘Here is the spot where it’s happening,’ ” Eagleman told me. “But the interesting thing about time is that there is no spot. It’s a distributed property. It’s metasensory; it rides on top of all the others.”

The real mystery is how all this is coördinated. When you watch a ballgame or bite into a hot dog, your senses are in perfect synch: they see and hear, touch and taste the same thing at the same moment. Yet they operate at fundamentally different speeds, with different inputs. Sound travels more slowly than light, and aromas and tastes more slowly still. Even if the signals reached your brain at the same time, they would get processed at different rates. The reason that a hundred-metre dash starts with a pistol shot rather than a burst of light, Eagleman pointed out, is that the body reacts much more quickly to sound. Our ears and auditory cortex can process a signal forty milliseconds faster than our eyes and visual cortex—more than making up for the speed of light. It’s another vestige, perhaps, of our days in the jungle, when we’d hear the tiger long before we’d see it.

In Eagleman’s essay “Brain Time,” published in the 2009 collection “What’s Next? Dispatches on the Future of Science,” he borrows a conceit from Italo Calvino’s “Invisible Cities.” The brain, he writes, is like Kublai Khan, the great Mongol emperor of the thirteenth century. It sits enthroned in its skull, “encased in darkness and silence,” at a lofty remove from brute reality. Messengers stream in from every corner of the sensory kingdom, bringing word of distant sights, sounds, and smells. Their reports arrive at different rates, often long out of date, yet the details are all stitched together into a seamless chronology. The difference is that Kublai Khan was piecing together the past. The brain is describing the present—processing reams of disjointed data on the fly, editing everything down to an instantaneous now. (…)

[Eagleman] thought of time not just as a neuronal computation—a matter for biological clocks—but as a window on the movements of the mind. (…)

You feel it now—not in half a second. But perception and reality are often a little out of register, as the saccade experiment showed. If all our senses are slightly delayed, we have no context by which to measure a given lag. Reality is a tape-delayed broadcast, carefully censored before it reaches us.

“Living in the past may seem like a disadvantage, but it’s a cost that the brain is willing to pay,” Eagleman said. “It’s trying to put together the best possible story about what’s going on in the world, and that takes time.” Touch is the slowest of the senses, since the signal has to travel up the spinal cord from as far away as the big toe. That could mean that the over-all delay is a function of body size: elephants may live a little farther in the past than hummingbirds, with humans somewhere in between. The smaller you are, the more you live in the moment. (…)

[T]ime and memory are so tightly intertwined that they may be impossible to tease apart.”

One of the seats of emotion and memory in the brain is the amygdala, he explained. When something threatens your life, this area seems to kick into overdrive, recording every last detail of the experience. The more detailed the memory, the longer the moment seems to last. “This explains why we think that time speeds up when we grow older,” Eagleman said—why childhood summers seem to go on forever, while old age slips by while we’re dozing. The more familiar the world becomes, the less information your brain writes down, and the more quickly time seems to pass. (…)

“Time is this rubbery thing,” Eagleman said. “It stretches out when you really turn your brain resources on, and when you say, ‘Oh, I got this, everything is as expected,’ it shrinks up.” The best example of this is the so-called oddball effect—an optical illusion that Eagleman had shown me in his lab. It consisted of a series of simple images flashing on a computer screen. Most of the time, the same picture was repeated again and again: a plain brown shoe. But every so often a flower would appear instead. To my mind, the change was a matter of timing as well as of content: the flower would stay onscreen much longer than the shoe. But Eagleman insisted that all the pictures appeared for the same length of time. The only difference was the degree of attention that I paid to them. The shoe, by its third or fourth appearance, barely made an impression. The flower, more rare, lingered and blossomed, like those childhood summers. (…)”

— Burkhard Bilger speaking about David Eagleman, neuroscientist at Baylor College of Medicine, where he directs the Laboratory for Perception and Action and the Initiative on Neuroscience and Law, The Possibilian, The New Yorker, Aprill 25, 2011 (Illustration source)

See also:

☞ David Eagleman on how we constructs reality, time perception, and The Secret Lives of the Brain
☞ David Eagleman, Brain Time, Edge, June 24, 2009 
☞ David Eagleman on the conscious mind
☞ The Experience and Perception of Time, Stanford Encyclopedia of Philosophy
☞ Time tag on Lapidarium notes

Why Does Beauty Exist? Jonah Lehrer: ‘Beauty is a particularly potent and intense form of curiosity’

                          
                                Interwoven Beauty by John Lautermilch

Curiosity

“Here’s my (extremely speculative) theory: Beauty is a particularly potent and intense form of curiosity. It’s a learning signal urging us to keep on paying attention, an emotional reminder that there’s something here worth figuring out. Art hijacks this ancient instinct: If we’re looking at a Rothko, that twinge of beauty in the mOFC is telling us that this painting isn’t just a blob of color; if we’re listening to a Beethoven symphony, the feeling of beauty keeps us fixated on the notes, trying to find the underlying pattern; if we’re reading a poem, a particularly beautiful line slows down our reading, so that we might pause and figure out what the line actually means. Put another way, beauty is a motivational force that helps modulate conscious awareness. The problem beauty solves is the problem of trying to figure out which sensations are worth making sense of and which ones can be easily ignored.

Let’s begin with the neuroscience of curiosity, that weak form of beauty. There’s an interesting recent study from the lab of Colin Camerer at Caltech, led by Min Jeong Kang. (…)

The first thing the scientists discovered is that curiosity obeys an inverted U-shaped curve, so that we’re most curious when we know a little about a subject (our curiosity has been piqued) but not too much (we’re still uncertain about the answer). This supports the information gap theory of curiosity, which was first developed by George Loewenstein of Carnegie-Mellon in the early 90s. According to Loewenstein, curiosity is rather simple: It comes when we feel a gap “between what we know and what we want to know”. This gap has emotional consequences: it feels like a mental itch. We seek out new knowledge because we that’s how we scratch the itch.

The fMRI data nicely extended this information gap model of curiosity. It turns out that, in the moments after the question was first asked, subjects showed a substantial increase in brain activity in three separate areas: the left caudate, the prefrontal cortex and the parahippocampal gyri. The most interesting finding is the activation of the caudate, which seems to sit at the intersection of new knowledge and positive emotions. (For instance, the caudate has been shown to be activated by various kinds of learning that involve feedback, while it’s also been closely linked to various parts of the dopamine reward pathway.) The lesson is that our desire for more information – the cause of curiosity – begins as a dopaminergic craving, rooted in the same primal pathway that responds to sex, drugs and rock and roll.

I see beauty as a form of curiosity that exists in response to sensation, and not just information. It’s what happens when we see something and, even though we can’t explain why, want to see more. But here’s the interesting bit: the hook of beauty, like the hook of curiosity, is a response to an incompleteness. It’s what happens when we sense something missing, when there’s a unresolved gap, when a pattern is almost there, but not quite. I’m thinking here of that wise Leonard Cohen line: “There’s a crack in everything – that’s how the light gets in.” Well, a beautiful thing has been cracked in just the right way.

Beautiful music and the brain

The best way to reveal the link between curiosity and beauty is with music. Why do we perceive certain musical sounds as beautiful? On the one hand, music is a purely abstract art form, devoid of language or explicit ideas. The stories it tells are all subtlety and subtext; there is no content to get curious about. And yet, even though music says little, it still manages to touch us deep, to tittilate some universal dorsal hairs.

We can now begin to understand where these feelings come from, why a mass of vibrating air hurtling through space can trigger such intense perceptions of beauty. Consider this recent paper in Nature Neuroscience by a team of Montreal researchers. (…)

Because the scientists were combining methodologies (PET and fMRI) they were able to obtain a precise portrait of music in the brain. The first thing they discovered (using ligand-based PET) is that beautiful music triggers the release of dopamine in both the dorsal and ventral striatum. This isn’t particularly surprising: these regions have long been associated with the response to pleasurable stimuli. The more interesting finding emerged from a close study of the timing of this response, as the scientists looked to see what was happening in the seconds before the subjects got the chills.
I won’t go into the precise neural correlates – let’s just say that you should thank your right nucleus accumbens the next time you listen to your favorite song – but want to instead focus on an interesting distinction observed in the experiment:

                                                      Click image to enlarge

In essence, the scientists found that our favorite moments in the music – those sublimely beautiful bits that give us the chills – were preceeded by a prolonged increase of activity in the caudate, the same brain area involved in curiosity. They call this the “anticipatory phase,” as we await the arrival of our favorite part:

Immediately before the climax of emotional responses there was evidence for relatively greater dopamine activity in the caudate. This subregion of the striatum is interconnected with sensory, motor and associative regions of the brain and has been typically implicated in learning of stimulus-response associations and in mediating the reinforcing qualities of rewarding stimuli such as food.

In other words, the abstract pitches have become a primal reward cue, the cultural equivalent of a bell that makes us drool. Here is their summary:

The anticipatory phase, set off by temporal cues signaling that a potentially pleasurable auditory sequence is coming, can trigger expectations of euphoric emotional states and create a sense of wanting and reward prediction. This reward is entirely abstract and may involve such factors as suspended expectations and a sense of resolution. Indeed, composers and performers frequently take advantage of such phenomena, and manipulate emotional arousal by violating expectations in certain ways or by delaying the predicted outcome (for example, by inserting unexpected notes or slowing tempo) before the resolution to heighten the motivation for completion.

(…)

While music can often seem (at least to the outsider) like an intricate pattern of pitches – it’s art at its most mathematical – it turns out that the most important part of every song or symphony is when the patterns break down, when the sound becomes unpredictable. If the music is too obvious, it is annoyingly boring, like an alarm clock. (Numerous studies, after all, have demonstrated that dopamine neurons quickly adapt to predictable rewards. If we know what’s going to happen next, then we don’t get excited.) This is why composers introduce the tonic note in the beginning of the song and then studiously avoid it until the end. They want to make us curious, to create a beautiful gap between what we hear and what we want to hear.

To demonstrate this psychological principle, the musicologist Leonard Meyer, in his classic book Emotion and Meaning in Music (1956), analyzed the 5th movement of Beethoven’s String Quartet in C-sharp minor, Op. 131. Meyer wanted to show how music is defined by its flirtation with – but not submission to – our expectations of order. To prove his point, Meyer dissected fifty measures of Beethoven’s masterpiece, showing how Beethoven begins with the clear statement of a rhythmic and harmonic pattern and then, in an intricate tonal dance, carefully avoids repeating it. What Beethoven does instead is suggest variations of the pattern. He is its evasive shadow. If E major is the tonic, Beethoven will play incomplete versions of the E major chord, always careful to avoid its straight expression. He wants to preserve an element of uncertainty in his music, making our brains exceedingly curious for the one chord he refuses to give us. Beethoven saves that chord for the end.

According to Meyer, it is the suspenseful tension of music (arising out of our unfulfilled expectations) that is the source of the music’s beauty. While earlier theories of music focused on the way a noise can refer to the real world of images and experiences (its “connotative” meaning), Meyer argued that the emotions we find in music come from the unfolding events of the music itself. This “embodied meaning” arises from the patterns the symphony invokes and then ignores, from the ambiguity it creates inside its own form. “For the human mind,” Meyer writes, “such states of doubt and confusion are abhorrent. When confronted with them, the mind attempts to resolve them into clarity and certainty.” And so we wait, expectantly, for the resolution of E major, for Beethoven’s established pattern to be completed. This nervous anticipation, says Meyer, “is the whole raison d’etre of the passage, for its purpose is precisely to delay the cadence in the tonic.” The uncertainty – that crack in the melody – makes the feeling.

Why the feeling of beauty is useful

What I like about this speculation is that it begins to explain why the feeling of beauty is useful. The aesthetic emotion might have begun as a cognitive signal telling us to keep on looking, because there is a pattern here that we can figure out it. In other words, it’s a sort of a metacognitive hunch, a response to complexity that isn’t incomprehensible. Although we can’t quite decipher this sensation – and it doesn’t matter if the sensation is a painting or a symphony – the beauty keeps us from looking away, tickling those dopaminergic neurons and dorsal hairs. Like curiosity, beauty is a motivational force, an emotional reaction not to the perfect or the complete, but to the imperfect and incomplete. We know just enough to know that we want to know more; there is something here, we just don’t what. That’s why we call it beautiful.”

— Jonah Lehrer, American journalist who writes on the topics of psychology, neuroscience, and the relationship between science and the humanities, Why Does Beauty Exist?, Wired science, July 18, 2011

See also:

☞ Beauty is in the medial orbitofrontal cortex of the beholder, study finds
☞ Denis Dutton: A Darwinian theory of beauty, TED, Lapidarium transcript
☞ The Science of Art. A Neurological Theory of Aesthetic Experience
☞ Katherine Harmon, Brain on Beauty Shows the Same Pattern for Art and Music, Scientific American, July 7, 2011

Why harmony pleases the brain

“The key to pleasant music may be that it pleases our neurons. A new model suggests that harmonious musical intervals trigger a rhythmically consistent firing pattern in certain auditory neurons, and that sweet sounds carry more information than harsh ones.

Since the time of the ancient Greeks, we have known that two tones whose frequencies were related by a simple ratio like 2:1 (an octave) or 3:2 (a perfect fifth) produce the most pleasing, or consonant, musical intervals. This effect doesn’t depend on musical training – infants and even monkeys can hear the difference. But it was unclear whether consonant chords are easier on the ears because of the way the sound waves combine in the air, or the way our brains convert them to electrical impulses. A new mathematical model presents a strong case for the brain.

“We have found that the reason for this difference is somewhere at the level of neurons,” says Yuriy Ushakov at the N. I. Lobachevsky State University of Nizhniy Novgorod in Russia.

Ushakov and colleagues considered a simple mathematical model of the way sound travels from the ear to the brain. In their model, two sensory neurons react to different tones. Each sends an electrical signal to a third neuron, called an interneuron, which sends a final signal to the brain. The model’s interneuron fires when it receives input from either or both sensory neurons.

However, the signals from the sensory neurons arrive at the same time if the tone is consonant, and so the interneuron still fires just once, then waits until it “recharges” before it fires again. The result is a regular train of pulses.

By contrast, the signals from dissonant tones arrive at different times and so generate an irregularly spaced train of pulses in the interneuron.

The researchers took their analysis one step further, and calculated the amount of information each signal carries. In the terms of information theory, a random signal carries very little information; a signal with a discernable pattern carries more. So naturally, the consonant notes carry more information than dissonant ones. They then used this to calculate the information content of the pulse trains generated by consonant and dissonant tones.”

— Lisa Grossman, Why harmony pleases the brain, New Scientist, 19 Sept 2011 (Illustration source)

Steven Pinker on the mind as a system of ‘organs of computation’

“I present the mind as a system of “organs of computation” that allowed our ancestors to understand and outsmart objects, animals, plants, and each other. (…)

Most of the assumptions about the mind that underlie current discussions are many decades out of date. Take the hydraulic model of Freud, in which psychic pressure builds up in the mind and can burst out unless it’s channeled into appropriate pathways. That’s just false. The mind doesn’t work by fluid under pressure or by flows of energy; it works by information.

Or, look at the commentaries on human affairs by pundits and social critics. They say we’re “conditioned” to do this, or “brainwashed” to do that, or “socialized” to believe such and such. Where do these ideas come from? From the behaviorism of the 1920’s, from bad cold war movies from the 1950’s, from folklore about the effects of family upbringing that behavior genetics has shown to be false. The basic understanding that the human mind is a remarkably complex processor of information, an “organ of extreme perfection and complication,” to use Darwin’s phrase, has not made it into the mainstream of intellectual life. (…)

I see the mind as an exquisitely engineered device—not literally engineered, of course, but designed by the mimic of engineering that we see in nature, natural selection. That’s what “engineered” animals’ bodies to accomplish improbable feats, like flying and swimming and running, and it is surely what “engineered” the mind to accomplish its improbable feats. (…)

What research in psychology should be: a kind of reverse engineering. When you rummage through an antique store and come across a contraption built of many finely meshing parts, you assume that it was put together for a purpose, and that if you only understood that purpose, you’d have insight as to why it has the parts arranged the way they are. That’s true for the mind as well, though it wasn’t designed by a designer but by natural selection. With that insight you can look at the quirks of the mind and ask how they might have made sense as solutions to some problem our ancestors faced in negotiating the world. That can give you an insight into what the different parts of the mind are doing.

Even the seemingly irrational parts of the mind, like strong passions—jealousy, revenge, infatuation, pride—might very well be good solutions to problems our ancestors faced in dealing with one another. For example, why do people do crazy things like chase down an ex-lover and kill the lover? How could you win someone back by killing them? It seems like a bug in our mental software. But several economists have proposed an alternative. If our mind is put together so that under some circumstances we are compelled to carry out a threat regardless of the costs to us, the threat is made credible. When a person threatens a lover, explicitly or implicitly, by communicating “If you ever leave me I’ll chase you down,” the lover could call his bluff if she didn’t have signs that he was crazy enough to carry it out even though it was pointless. And so the problem of building a credible deterrent into creatures that interact with one another leads to irrational behavior as a rational solution. “Rational,” that is, with respect to the “goal” of our genes to maximize the number of copies of themselves. It isn’t “rational,” of course, with respect to the goal of whole humans and societies to maximize happiness and fairness. (…)

The paradoxes of happiness

There’s no absolute standard for well-being. A Paleolithic hunter-gatherer should not have fretted that he had no running shoes or central heating or penicillin. How can a brain know whether there is something worth striving for? Well, it can look around and see how well off other people are. If they can achieve something, maybe so can you. Other people anchor your well-being scale and tell you what you can reasonably hope to achieve. (…)

Another paradox of happiness is that losses are felt more keenly than gains. As Jimmy Connors said, “I hate to lose more than I like to win.” You are just a little happy if your salary goes up, but you’re really miserable if your salary goes down by the same amount. That too might be a feature of the mechanism designed to attain the attainable and no more. When we backslide, we keenly feel it because what we once had is a good estimate of what we can attain. But when we improve we have no grounds for knowing that we are as well off as we can hope to be. The evolutionary psychologist Donald Campbell called it “the happiness treadmill.” No matter how much you gain in fame, wealth, and so on, you end up at the same level of happiness you began with—though to go down a level is awful. Perhaps it’s because natural selection has programmed our reach to exceed our grasp, but by just a little bit. (…)

The brain as a kind of computer; information processing system

I place myself among those who think that you can’t understand the mind only by looking directly at the brain. Neurons, neurotransmitters, and other hardware features are widely conserved across the animal kingdom, but species have very different cognitive and emotional lives. The difference comes from the ways in which hundreds of millions of neurons are wired together to process information. I see the brain as a kind of computer—not like any commercial computer made of silicon, obviously, but as a device that achieves intelligence for some of the same reasons that a computer achieves intelligence, namely processing of information. (…)

I also believe that the mind is not made of Spam—it has a complex, heterogeneous structure. It is composed of mental organs that are specialized to do different things, like seeing, controlling hands and feet, reasoning, language, social interaction, and social emotions. Just as the body is divided into physical organs, the mind is divided into mental organs.

That puts me in agreement with Chomsky and against many neural network modelers, who hope that a single kind of neural network, if suitably trained, can accomplish every mental feat that we do. For similar reasons I disagree with the dominant position in modern intellectual life—that our thoughts are socially constructed by how we were socialized as children, by media images, by role models, and by conditioning. (…)

Many people lump together the idea that the mind has a complex innate structure with the idea that differences between people have to be innate. But the ideas are completely different. Every normal person on the planet could be innately equipped with an enormous catalog of mental machinery, and all the differences between people—what makes John different from Bill—could come from differences in experience, of upbringing, or of random things that happened to them when they were growing up.

To believe that there’s a rich innate structure common to every member of the species is different from saying the differences between people, or differences between groups, come from differences in innate structure. Here’s an example. Look at number of legs—it’s an innate property of the human species that we have two legs as opposed to six like insects, or eight like spiders, or four like cats—so having two legs is innate. But if you now look at why some people have one leg, and some people have no legs, it’s completely due to the environment—they lost a leg in an accident, or from a disease. So the two questions have to be distinguished. And what’s true of legs is also true of the mind. (…)

Computer technology will never change the world as long as it ignores how the mind works. Why did people instantly start to use fax machines, and continue to use them even though electronic mail makes much more sense? There are millions of people who print out text from their computer onto a piece of paper, feed the paper into a fax machine, forcing the guy at the other end to take the paper out, read it, and crumples it up—or worse, scan it into his computer so that it becomes a file of bytes all over again. This is utterly ridiculous from a technological point of view, but people do it. They do it because the mind evolved to deal with physical objects, and it still likes to conceptualize entities that are owned and transferred among people as physical objects that you can lift and store in a box. Until computer systems, email, video cameras, VCR’s and so on are designed to take advantage of the way the mind conceptualizes reality, namely as physical objects existing at a location and impinged upon by forces, people are going to be baffled by their machines, and the promise of the computer revolution will not be fulfilled. (…)

Q: What is the significance of the Internet and today’s communications revolution for the evolution of the mind?

Probably not much. You’ve got to distinguish two senses of the word “evolution.” The sense used by me, Dawkins, Gould, and other evolutionary biologists refers to the changes in our biological makeup that led us to be the kind of organism we are today. The sense used by most other people refers to continuous improvement or progress. A popular idea is that our biological evolution took us to a certain stage, and our cultural evolution is going to take over—where evolution in both cases is defined as “progress.” I would like us to move away from that idea, because that the processes that selected the genes that built our brains are different form the processes that propelled the rise and fall of empires and the march of technology and.

In terms of strict biological evolution, it’s impossible to know where, if anywhere, our species is going. Natural selection generally takes hundreds of thousands of years to do anything interesting, and we don’t know what our situation will be like in ten thousand or even one thousand years. Also, selection adapts organism to a niche, usually a local environment, and the human species moves all over the place and lurches from life style to life style with dizzying speed on the evolutionary timetable. Revolutions in human life like the agricultural, industrial, and information revolutions occur so quickly that no one can predict whether the change they will have on our makeup, or even whether there will be a change.

The Internet does create a kind of supra-human intelligence, in which everyone on the planet can exchange information rapidly, a bit like the way different parts of a single brain can exchange information. This is not a new process; it’s been happening since we evolved language. Even non-industrial hunter-gatherer tribes pool information by the use of language.

That has given them remarkable local technologies—ways of trapping animals, using poisons, chemically treating plant foods to remove the bitter toxins, and so on. That is also a collective intelligence that comes from accumulating discoveries over generations, and pooling them amongst a group of people living at one time. Everything that’s happened since, such as writing, the printing press, and now the Internet, are ways of magnifying something that our species already knew how to do, which is to pool expertise by communication. Language was the real innovation in our biological evolution; everything since has just made our words travel farther or last longer.”

— Steven Pinker, Canadian-American experimental psychologist, cognitive scientist and linguist, Organs of Computation, Edge, January 11, 1997 (Illustration source)

See also:

☞ Steven Pinker, Harvard University Cambridge, MA, So How Does the Mind Work? (pdf), Blackwell Publishing Ltd. 2005

The Optimism Bias and Memory

“The belief that the future will be much better than the past and present is known as the optimism bias. (…)

The bias also protects and inspires us: it keeps us moving forward rather than to the nearest high-rise ledge. Without optimism, our ancestors might never have ventured far from their tribes and we might all be cave dwellers, still huddled together and dreaming of light and heat.

To make progress, we need to be able to imagine alternative realities — better ones — and we need to believe that we can achieve them. (…)

A growing body of scientific evidence points to the conclusion that optimism may be hardwired by evolution into the human brain. (…)

Our brains aren’t just stamped by the past. They are constantly being shaped by the future. (…)

Scientists who study memory proposed an intriguing answer: memories are susceptible to inaccuracies partly because the neural system responsible for remembering episodes from our past might not have evolved for memory alone. Rather, the core function of the memory system could in fact be to imagine the future (…) The system is not designed to perfectly replay past events. (…) It is designed to flexibly construct future scenarios in our minds. As a result, memory also ends up being a reconstructive process, and occasionally, details are deleted and others inserted.”

— Tali Sharot, a British Academy postdoctoral fellow at the Wellcome Trust Centre for Neuroimaging at University College London, Optimism Bias: Human Brain May Be Hardwired for Hope, Time, June 6, 2011

Remembering the past to imagine the future

“A rapidly growing number of recent studies show that imagining the future depends on much of the same neural machinery that is needed for remembering the past. These findings have led to the concept of the prospective brain; an idea that a crucial function of the brain is to use stored information to imagine, simulate and predict possible future events. We suggest that processes such as memory can be productively re-conceptualized in light of this idea. (…)

Thoughts of past and future events are proposed to draw on similar information stored in episodic memory and rely on similar underlying processes, and episodic memory is proposed to support the construction of future events by extracting and recombining stored information into a simulation of a novel event. The hypothesis receives general support from findings of neural and cognitive overlap between thoughts of past and future events. (…)



Future events were more vivid and more detailed when imagined in recently experienced contexts (university locations) than when imagined in remotely experienced contexts (school settings). These results support the idea that episodic information is used to construct future event simulations. (…)

The core brain system is also used by many diverse types of task that require mental simulation of alternative perspectives. The idea is that the core brain system allows one to shift from perceiving the immediate environment to an alternative, imagined perspective that is based largely on memories of the past. Future thinking, by this view, is just one of several forms of such ability. Thinking about the perspectives of others (theory of mind) also appears to use the core brain system, as do certain forms of navigation. (…)

From an adaptive perspective, preparing for the future is a vital task in any domain of cognition or behaviour that is important for survival. The processes of event simulation probably have a key role in helping individuals plan for the future, although they are also important for other tasks that relate to the present and the past.

Memory can be thought of as a tool used by the prospective brain to generate simulations of possible future events.”

— D. L. Schacter, D. Rose Addis & R. L. Buckner, Remembering the past to imagine the future: the prospective brain (pdf), Department of Psychology, Harvard University, and the Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital

See also:
☞ The Brain Memories Are Crucial for Looking Into the Future
☞ How the brain stops time, Lapidarium

                 

☞ K. K. Szpunar and K. B. McDermott, Episodic future thought and its relation to remembering: Evidence from ratings of subjective experience, Department of Psychology, Washington University
☞ Memory tag on Lapidarium notes

David Eagleman on how we constructs reality, time perception, and The Secret Lives of the Brain

How our brain constructs reality

“The conscious mind—which is the part of you that flickers to life when you wake up in the morning: that bit of you—it’s like a stowaway on a transatlantic steamship, that’s taking credit for the journey, without acknowledging all the engineering underfoot.

I think what this means when we’re talking about knowing ourselves is exactly
what it meant when people were trying to understand our place in the cosmos,
400 years ago, when Galileo discovered the moons of Jupiter and realized that, in fact, we’re not at the center of things, but instead we’re way out on a distant edge. That’s essentially the same situation we’re in, where we’ve fallen from the center of ourselves.

But in Galileo’s case, what that caused is we now have a much more nuanced view of the cosmos. As Carl Sagan was fond of saying, it’s more wondrous and subtle than we could have ever imagined. And I think it’s exactly the same thing going on with the brain: we’re falling from the center of the brain, but what we’re discovering is that it’s much more amazing than we could have ever thought when we imagined that we were the ones sort of at the center of everything and driving the boat. (…)

As we want to go on this journey of exploring what the heck we’re made out of, the first thing to do is to recognize that what you’re seeing out there is not actually reality. You’re not sort of opening your eyes, and voila, there’s the world. Instead, your brain constructs the world. Your brain is trapped in darkness inside of your skull, and all it ever sees are electrical and chemical signals. So all the colors you see, and so on, that doesn’t really exist; that’s an interpretation by your brain. (…)

All we’re actually doing is seeing an internal model of the world; we’re not seeing what’s out there, we’re seeing just our internal model of it. And that’s why, when you move your eyes around, all you’re doing is updating that model.

And for that matter, when you blink your eyes and there are 80 milliseconds of blackness there, you don’t notice that, either. Because it’s not actually about what’s coming in the eyes; it’s about your internal construction. And, in fact, as I mention in the book, we don’t even need our eyes to see. When you are asleep and dreaming, your eyes are closed, but you’re having full, rich visual experience —because it’s the same process of running your visual cortex, and then you believe that you are seeing. (…)

Because all the brain ever sees are these electrical and chemical signals, and it doesn’t necessarily know or care which ones are coming in through the eyes, or the ears, or the fingertips, or smell, or taste. All these things get converted just to electrical signals.

And so, it turns out what the brain is really good at—and the cortex in particular —is in extracting information that has some sort of useful correlation with things in the outside world. And so, if you feed, let’s say, visual input into your ears, you will figure out how to see through your ears. Because the brain doesn’t care how it gets there; all it cares about is, Oh, there’s structure to this data that I can extract. (…)

I think it’s sort of the most amazing thing about the way brains are built, is they’re constantly reconfiguring their own circuitry. (…)

It turns out that one of the main jobs of the brain is to save energy; and the way that it does this is by predicting what is going to come next. And if it sort of has a pretty good prediction of what’s happening next, then it doesn’t need to burn a lot of energy when that thing happens, because it’s already foreseen it. (…)

So, the job of the brain is to figure out what’s coming next; and if you have successfully done it, then there’s no point in consciousness being a part of what’s going on. (…)

Time perception

You’re not passively just watching the river of time flow by. Instead, just like with visual illusions, your brain is actively constructing time. (…)

When you can predict something, not only does your consciousness not come
online, but it feels like it goes very fast. So, driving to work is very fast; but the
very first time you did it, it seemed to take very long time. And it’s because of the
novelty and the amount of energy you had to burn the first time you did it—
before you were able to predict it.

Essentially what prediction means, if it’s something you’re doing a lot, is that
you’re actually reconfiguring the circuitry of the brain. You’re actually getting
stuff down into the circuitry, which gives you speed and efficiency, but at the cost
of conscious access. (…)

It’s not only the way we see vision and time, but it’s all of our cognition: it’s our morals, it’s what we’re attracted to, it’s what we believe in. All of these things are served up from these subterranean caverns of the mind. We often don’t have any access to what’s going on down there, and why we believe the things we do, why we act the way we do. (…)

The “illusion of truth”

You give people statements to rate the truth value of, and then you bring them back a while later and you give them more statements to say whether they’re true or false, and so on. But it turns out that if you repeat some of the statements from the first time to the second time, just because the people have heard them before, whether or not it’s true and whether or not they even marked it as false last time, because they’re hearing it again— unconsciously they know they’ve heard it before—they’re more likely to rate it as true now. (…)

I think this is part of the brain toolbox that children need: to really practice and learn skepticism and critical thinking skills. (…)

Some thoughts aren’t thinkable, because of the way that thoughts are constrained by our biology

Yes. As far as thoughts that we’re not able to think, that’s an idea that I just love to explore, because there’s all kinds of stuff we can’t see. Just as an example, if you take the electromagnetic radiation spectrum, what we call visible light is just one ten-billionth of that spectrum. So, we’re only seeing a very tiny sliver of that, because we have biological receptors that are tuned to that little part of the spectrum. But radio signals, and cell phone signals, and television signals, all that stuff is going right through your body, because you happen not to have biological receptors for that part of the spectrum.

So, what that means is that there’s a particular slice of the world that you can see. And what I wanted to explore in the book is that there’s also a slice of the world that you can think. In other words, because of evolutionary pressures, our psychology has been carved to think certain thoughts—this is the field known as evolutionary psychology—and that means there are other thoughts that are just like the cell phone signals, and radio signals, and so on, that we can’t even access.

Just as an example, try being sexually attracted to something that you’re not—like a chicken or a frog. But chickens and frogs find that to be the greatest thing in the world, to look at another chicken or frog. We only find that with humans. So, different species, which have otherwise pretty similar brains, have these very specific differences about the kinds of thoughts they can think. (…)

As far as nature vs. nurture goes, the answer nowadays is always both. It’s sort of a dead question to ask—nature vs. nurture—because it is absolutely true that we do not come to the table as a blank slate; we have a lot of stuff that we come to the table with predisposed. But the whole rest of the process is an unpacking of the brain by world experience. (…)

The brain as the team of rivals. Rational vs. emotional

So, the way your brain ends up in the end is a very complicated tangle of genetics and environment. And environment includes, not only all of your childhood experiences and so on, but your in utero environment, toxins in the air, the things that you eat, experiences of abuse, and all of that stuff—and your culture; your culture has a lot to do with the way your brain gets wired up. (…)

One of the culminating issues in the book is that your brain is really like a team of rivals, where you have these different neural subpopulations that are always battling it out to control the one-output channel of your behavior; and you’ve got all these different networks that are fighting it out. And so, there are parts of your brain that can be xenophobic, and other parts of your brain that maybe decide to overwrite that, and they’re not xenophobic. And I think this gives us a much more nuanced view, in the end, of who we are, and also who other people are. (…)

When people do neuroimaging studies, you can actually find situations where it looks like you have some parts that are doing essentially a math problem in the brain, and other parts that really care about how things feel, and how they’ll make the body feel. And you can image these different networks, and you can also see when they’re fighting one another when trying to do some sort of moral decision-making.

So, probably the best way for us to look at it is that when we talk about reason vs. emotion, we’re talking about sort of a summary—sort of a shorthand way of talking about these different neural networks. And, of course, decisions can be much more complicated than that, often. But sometimes they can be essentially boiled down to that.

It’s funny; the ancient Greeks also felt that this was the right way to divide it.
Again, it’s an oversimplification, but the Greeks had this idea that life is like
you’re a charioteer, and you’re holding the white horse of reason and the black horse of passion, and they’re both always trying to pull you off the road in different directions, and your job is to keep down the middle. And that’s about right. They had some insight there into that you do have these competing networks. (…)

The field of artificial intelligence

The field of artificial intelligence has become stuck, and I’m trying to figure
out why. I think it’s because when programmers are trying to make a robot do something, they come up with solutions: like here’s how you find the block of
wood, here’s how you grip the block of wood, here’s how you stack the block of
wood, and so on. And each time they make a little subroutine to take care of a
little piece of the problem; then they say, OK, good; that part’s done.

But Mother Nature never does that. Mother Nature chronically reinvents things all the time—accidentally. Just by mutation, there are always new ways to do things, like detect motion, or control muscles, or whatever it is that it’s trying to do—pick up on new energy sources, and so on. And as a result, what you have are multiple ways of solving problems in real biological creatures.

They don’t divide up neatly into little modules, the same way that a computer
program does, but instead, for example, in the mammalian cortex it appears that Mother Nature probably came up with about three or four different ways to detect motion. And all of these act like parties in the neural parliament. They all sort of think that they know how to detect motion best, and they battle it out with the other parties.

And so, I think this is one of the main lessons that we get, when we look for it, in what happens when we see brain damage in people. You can lose aspects of your vision and not lose other aspects; or, often, you can get brain damage and you don’t see a deficit at all, even though you’ve just sort of bombed out part of what you would expect to give a deficit.

In other words, you have this very complicated interaction of these different
parties that are battling it out. And I think they, in general, don’t divide neatly
along the cortical and subcortical division, but instead, whether in lizard brains
or in our brains, these networks can be made up of subcortical and cortical parts
together. (…)

The illusion we have that we have control

The analogy of a young monarch who takes the throne of his country, and takes credit for the glory of the country without thinking about the thousands of workers who are making it all work. And that’s essentially the situation we’re in.

Take, just as an example, when you have an idea, you say, ‘Oh, I just thought of
something.’ But it wasn’t actually you that thought of it. Your brain has been
working on that behind the scenes for hours or days, consolidating information,
putting things together, and finally it serves up something to you. It serves up an
idea; and then you take credit for it. But this whole things leads to this very
interesting question about the illusion we have that we have control. (…)

What does this mean for responsibility?

I think what it means is that when we look at something like the legal system, something like blameworthiness is actually the wrong question for us to ask. I mentioned before that brains end up being an end result of a very complicated process of genes intertwining with environment. So, in the end, when there’s a brain standing in front of the judge’s bench, it doesn’t matter for us to say, OK, well, are you blameworthy; to what extent are you blameworthy; to what extent was it your biology vs. you; because it’s not clear that there’s any meaningful difference between those two things, anyway.

I’m not saying this forgives anybody. We still have to take people off the street if they’re breaking the law. But what it means is that asking the question of blameworthiness isn’t where we should be putting our time. Instead, all we need to be doing is having a forward-looking legal system, where we say what do we do with you from here?

We don’t care how you got here, because we can’t ever know. It might have been
in utero cocaine poisoning, childhood abuse, lead paint on the walls, and all of
these other things that influenced your brain development, but we can’t untangle
that. And it’s not anybody’s fault. It’s not your fault or anybody else’s. But we
can’t do anything about it.

So, all we need to do is say, given the kind of person you are now, what is the
probability of recidivism. In other words, how likely are you to transfer this
behavior to a future situation and re-offend? And then we can predicate sentence
length on that probability of re-offense. And, equally as importantly, along with
customized sentencing, we can have customized rehabilitation.

So, there are lots of things that can go wrong with people’s brains that we can
usefully address, and try to help people, instead of throwing everybody in jail. As it stands now, 30% of the prison population has mental illness. Not only is that not a humane way for us to treat our mentally ill and make a de facto healthcare system, but it’s also not cost-effective.

And it’s also criminogenic—meaning it causes more crime. Because everybody
knows when you put people in jail, that limits their employment opportunities, it
breaks their social circles, and they end up coming back to the jail, more often
than not. So, it’s very clear how the legal system should be straightening itself out, just to make itself forward-looking, and saying, OK, all we need to do is get good at assessing risk into the future. (…)

A neural parliament

One of the really amazing lessons is this bit about being a neural parliament,
and not being made up of just one thing. I think this gives us a much better view
of why we can argue with ourselves, and curse at ourselves, and contract with
ourselves, and why we can do things where we look back and we think, Wow,
how did I do that? I’m not the kind of person who would do that.

But, in fact, you are many people. As Walt Whitman said, “I am large, I contain multitudes.” So, I think this gives us a better view of ourselves, and it also tells us ways to set up our own behavior to become the kind of people we want to be, by thinking about how to structure things in our life so that the short-term parties that are interested in instant impulse gratification—so that they don’t always win the battle.”

— David Eagleman, neuroscientist at Baylor College of Medicine, where he directs the Laboratory for Perception and Action and the Initiative on Neuroscience and Law, Interview with Dr. David Eagleman, Author of Incognito: The Secret Lives of the Brain, Brain Science Podcast, Episode #75, Originally Aired 7/8/2011 (transcript in pdf) (Illustration source: David Plunkert for TIME)

The brain… it makes you think. Doesn’t it?

David Eagleman: “A person is not a single entity of a single mind: a human is built of several parts, all of which compete to steer the ship of state. As a consequence, people are nuanced, complicated, contradictory. We act in ways that are sometimes difficult to detect by simple introspection. To know ourselves increasingly requires careful studies of the neural substrate of which we are composed. (…)

Raymond Tallis: Of course, everything about us, from the simplest sensation to the most elaborately constructed sense of self, requires a brain in some kind of working order. (…)

[But] we are not stand-alone brains. We are part of community of minds, a human world, that is remote in many respects from what can be observed in brains. Even if that community ultimately originated from brains, this was the work of trillions of brains over hundreds of thousands of years: individual, present-day brains are merely the entrance ticket to the drama of social life, not the drama itself. Trying to understand the community of minds in which we participate by imaging neural tissue is like trying to hear the whispering of woods by applying a stethoscope to an acorn. (…)

David Eagleman: The uses of neuroscience depend on the question being asked. Inquiries about economies, customs, or religious wars require an examination of what transpires between minds, not just within them. Indeed, brains and culture operate in a feedback loop, each influencing the other.

Nonetheless, culture does leave its signature in the circuitry of the individual brain. If you were to examine an acorn by itself, it could tell you a great deal about its surroundings – from moisture to microbes to the sunlight conditions of the larger forest. By analogy, an individual brain reflects its culture. Our opinions on normality, custom, dress codes and local superstitions are absorbed into our neural circuitry from the social forest around us. To a surprising extent, one can glimpse a culture by studying a brain. Moral attitudes toward cows, pigs, crosses and burkas can be read from the physiological responses of brains in different cultures.

Beyond culture, there are fruitful questions to be asked about individual experience. Your experience of being human – from thoughts to actions to pathologies to sensations – can be studied in your individual brain with some benefit. With such study, we can come to understand how we see the world, why we argue with ourselves, how we fall prey to cognitive illusions, and the unconscious data-streams of information that influence our opinions.

How did I become aware enough about unawareness to write about it in Incognito? It was an unlikely feat that required millennia of scientific observation by my predecessors. An understanding of the limitations of consciousness is difficult to achieve simply by consulting our intuition. It is revealed only by study.

To be clear, this limitation does not make us equivalent to automatons. But it does give a richer understanding of the wellspring of our ideas, moral intuitions, biases and beliefs. Sometimes these internal drives are genetically embedded, other times they are culturally instructed – but in all cases their mark ends up written into the fabric of the brain. (…)

Neuroscience is uncovering a bracing view of what’s happening below the radar of our conscious awareness, but that makes your life no more “helpless, ignorant, and zombie-like” than whatever your life is now. If you were to read a cardiology book to learn how your heart pumps, would you feel less alive and more despondently mechanical? I wouldn’t. Understanding the details of our own biological processes does not diminish the awe, it enhances it. Like flowers, brains are more beautiful when you can glimpse the vast, intricate, exotic mechanisms behind them.”

David Eagleman, neuroscientist at Baylor College of Medicine, where he directs the Laboratory for Perception and Action, bestselling author

Raymond Tallis, British philosopher, secular humanist, poet, novelist, cultural critic, former professor of geriatric medicine at Manchester University

— The brain… it makes you think. Doesn’t it?, The Guardian, The Observer, 29 April 2012.

See also:

☞ Time and the Brain. Eagleman: ‘Time is not just as a neuronal computation—a matter for biological clocks—but as a window on the movements of the mind’
☞ David Eagleman on the conscious mind
☞ David Eagleman on Being Yourselves, lecture at Conway Hall, London, 10 April 2011.
☞ The Experience and Perception of Time, Stanford Encyclopedia of Philosophy
☞ Your brain creates your sense of self, incognito, CultureLab, Apr 19, 2011.
☞ Dean Buonomano on ‘Brain Bugs’ - Cognitive Flaws That ‘Shape Our Lives’
☞ Iain McGilchrist on The Divided Brain and the Making of the Western World
☞ Daniel Kahneman: The Marvels and the Flaws of Intuitive Thinking
☞ The Relativity of Truth - a brief résumé, Lapidarium
☞ Timothy D. Wilson on The Social Psychological Narrative: ‘It’s not the objective environment that influences people, but their constructs of the world’
☞ David Eagleman, Your Brain Knows a Lot More Than You Realize, DISCOVER Magazine, Oct 27, 2011
☞ David Eagleman, Henry Markram, Will We Ever Understand the Brain?, California Academy of Sciences San Francisco, CA, Fora.tv video, 11.02.2011
☞ Bruce Hood, The Self Illusion: How the Brain Creates Identity, May, 2012
☞ Mind & Brain tag on Lapidarium

Beauty is in the medial orbitofrontal cortex of the beholder, study finds

                                     
                             Leonardo da Vinci, Mona Lisa (c. 1503–1519) (source)

“Beauty is in the forebrain of the beholder, a study has found.

Scientists have identified a region at the front of the brain that “lights up” in appreciation of art or music. But how active it becomes depends on personal taste, whether an individual finds pleasure from abstract art, classical masterpieces, grand opera or rock music.

The region, known as the medial orbito-frontal cortex, is also the most honest of art critics. It responds only on the basis of enjoyment rather than technical ability or “artistic merit”.

Professor Semir Zeki, from the Wellcome Laboratory of Neurobiology at University College London, who led the study, said: “The question of whether there are characteristics that render objects beautiful has been debated for millennia by artists and philosophers of art, but without an adequate conclusion.

“So too has the question of whether we have an abstract sense of beauty, that is to say one which arouses in us the same powerful emotional experience regardless of whether its source is, for example, musical or visual. It was time for neurobiology to tackle these fundamental questions.”

Professor Zeki’s team recruited 21 volunteers from different cultures and ethnic backgrounds, who were asked to rate a series of paintings or musical excerpts as “beautiful, indifferent or ugly”. The participants then looked at the pictures or listened to the music again while undergoing a functional magnetic resonance imaging brain scan.

Music and art previously rated as “beautiful” both stimulated activity in the medial orbito-frontal cortex, which lessened when volunteers were “indifferent”. In contrast, no brain region in particular responded to works rated as “ugly”.

Professor Zeki said: “Almost anything can be considered art but we argue that only creations whose experience correlates with activity in the medial orbito-frontal cortex would fall into the classification of beautiful art.” (…)

“A painting by Francis Bacon, for example, may have great artistic merit but may not qualify as beautiful. The same can be said for some of the more ‘difficult’ classical composers - and whilst their compositions may be viewed as more ‘artistic’ than rock music, to someone who finds the latter more rewarding and beautiful, we would expect to see greater activity in the particular brain region when listening to Van Halen than when listening to Wagner.”

— Beauty? Why, it’s all in the mind, The Scotsman, 07 July 2011, and in Wellcome Trust, July 7, 2011.

See also:

☞ Beauty is in the brain of the beholder, Discover Magazine
☞ Ishizu & Zeki, Toward A Brain-Based Theory of Beauty, PLoS ONE, 2011
☞ Beauty in a smile: the role of medial orbitofrontal cortex in facial attractiveness (pdf), Royal Free Hospital School of Medicine, London
☞ Alumit Ishai, Sex, beauty and the orbitofrontal cortex (pdf), Institute of Neuroradiology, University of Zurich
☞ Edmund T. Rolls, Fabian Grabenhorst, The orbitofrontal cortex and beyond: From affect to decision-making (pdf), University of Oxford, Department of Experimental Psychology, 2008
☞ Denis Dutton: A Darwinian theory of beauty, TED
☞ The Science of Art. A Neurological Theory of Aesthetic Experience, Lapidarium
☞ Why Does Beauty Exist? Jonah Lehrer: ‘Beauty is a particularly potent and intense form of curiosity’

Human Connectome Project ☞ understanding how different parts of the brain communicate to each other

                             
                                (Click image to go to the Human Connectome Project)

Mapping of the human connectome offers a unique opportunity to understand the complete details of neural connectivity. The Human Connectome Project (HCP) is a project to construct a map of the complete structural and functional neural connections in vivo within and across individuals. The HCP represents the first large-scale attempt to collect and share data of a scope and detail sufficient to begin the process of addressing deeply fundamental questions about human connectional anatomy and variation. A collaboration between MGH and UCLA, the HCP is being developed to employ advanced neuroimaging methods, and to construct an extensive informatics infrastructure to link these data and connectivity models to detailed phenomic and genomic data, building upon existing multidisciplinary and collaborative efforts currently underway.

General Diffusion in the Brain



The diffusion of water molecules in the brain, specifically Isotropisc Diffusion vs. Anisotropic diffusion, is an important element of white matter tractography.

Streamline Tractography



Tensor shapes are calculated inside the many voxels that make up brain scans by looking at the direction of water diffusion. Different scanning techniques allow for different levels of accuracy and detail.

(Animation by Carlos Mena. Narration and Music by Ellen Armour. Script by Amanda Hammond. Scientific Consultation by Arthur W. Toga, Ph.D.)

— Human Connectome Project, Laboratory of Neuro Imaging at UCLA and Martinos Center for Biomedical Imaging at Harvard, Human Connectome Project funded by National Institute of Health