Love speed dating

You may do better in relying on your impression after only 4 minutes of interaction with a potential partner than if you think about it a lot. Here is an engaging essay by Matt Kaplan.

The Blakeslees on the body's own mind...

"The Body Has a Mind of Its Own" is the title of a book being released today, September 11, by Sandra Blakeslee (N.Y.Times Science writer) and her son Matthew Blakeslee (also a science writer, making him the fourth generation of science writers in the family line!). Its subject is the maps that our brain makes of our internal and external worlds, including our feelings, emotions, and sense of self... and how plastic they can be. Much of the work they describe has been the subject of posts on this MindBlog. I enjoyed reading the book, and would highly recommend it. It crams an amazing amount of material into a small space. It is easy to read and engaging.

Here is one of the figures from the book, illustrating how our brain cells adapt to tool use, incorporating the tool into our body image.

How our brain changes when we (or monkeys, as in the figure) use a hand tool to extend our reach. Legend. a) Before learning to use a rake (left) or while passively holding the rake (right) without the intention of using it as a tool, the monkey's hand-centered visual-tacile receptive fields stay confined to the hand's immediate vicinity. But while the monkey is actively wielding the rake (center), the cells' visual receptive fields expand along its length. (Visual or tactile input to the shaded area causes a hand-centered cell in the parietal lobe to fire.) b). The visual-tacile receptive field expansion of one of the monkey's shoulder-centered neurons.

These positive points having been made, I felt during my reading like I was looking over the authors' shoulders as they were writing, and I kept wanting to suggest that the presentation be tightened up with more bottom lines brought up front. Many times I had the "Ah Ha!, why didn't they tell me THIS is where they were going" experience. With one study after another thrown onto the page I found myself loosing the thread. When I did find an interesting nugget I had not be aware of, I was frustrated by the fact that there is no bibliography or list of references provided. It would be very useful for the authors to provide such references on a website associated with the book.

There are many excellent summaries and quotable passages in the book. I like the ending paragraphs, which follow a discussion of the neural correlates of our sense of self, and how distortions in our sense of ownership can occur. A few clips:

So, is the self ultimately "just" an illusion?...According to the neuroscience of body maps - and incidentally, the majority of Eastern religions - in many respects, yes...A key point is that your mind feels like a seamless whole when "all your faculties" are working. But if your body mandala were to go on the fritz in one of a hundred ways, whether through damage to one map or several, or through a severing of between-map connections, you might suddenly experience extra arms, a phantom leg...hemineglect (where half the universe winks out of your awareness), alien hand syndrome, and all manner of delusions and misperceptions. Case studies of brain damage like these are one of the biggest philosophical, not to mention logical, arguments against the idea of a uniatry psychic core. When certain parts of the brain break, certain parts of the mind break; the illusion is spoiled, and the underlying multifariousness of the psyche is exposed......The illusion of the self is that self is a kernel, rather than a distributed, emergent system....Localizations of psychic functions are better said to exist in loops of information processing, or circuits, rather than specific points...the...psychic self...is an orchestra without a conductor or a fixed score, but whose players are so good at collaborative improv that wonderful music keeps flowing out of it. Just as the orchestra has no score and no conductor, the mind has no kernel, no "little man" sitting at the center of the fray directing the action. But it is teeming with noncentral "little men," the brain's motley team of homunculi, who form the backbone of the whole production. And you, thankfully, have the irreducible illusion of being the conductor of yours life's music in all its complexity, emotional nuace, crescendo and diminuendo - the ballad that is the you-ness of you."

How the body shapes intelligence

Kitano reviews a new book in Nature (PDE of review here): How the Body Shapes the Way We Think: A New View of Intelligence. by Rolf Pfeifer & Josh Bongard, Bradford Books: 2006. A few clips:

...a chess computer, unlike a human, does not have a body to enable it to interact with its environment, for example. This distinction differentiates two views on intelligence. One view is that intelligence is independent of the body and is unaffected by its existence, shape and function. The other view is that intelligence is contained within a physical body and that the body shapes the mind, an idea often referred to as physical embodiment or the presence of a behaviour-based agent.

The Pfeifer and Bongard book offers perspective on how artificial-intelligence and robotics researchers are dealing with the increasing recognition in the artificial-intelligence and robotics communities that the nature of the body significantly affects the mind, although it does not totally control it. The book focuses on artificial agents, but with a lot of inspiration from nature.

One salient difference between the intelligent agents discussed in this book and traditional artificial-intelligence systems, as represented by chess computers, is the contextual thickness of system behaviours. Many of the robotics systems discussed in the book can cope, at least to some extent, with changes in the expected environment, tasks and other assumed conditions, whereas chess computers and other traditional artificial-intelligence systems are usually extremely fragile when faced with even a small change in such conditions. Behaviour-based robots should be able to perform almost flawlessly if the size of road or unevenness of terrain deviates from the initial assumption. However, the results will be catastrophic if a chess computer is given a chess board with nine rows and columns, rather than eight, as they are tuned specifically for the existing rules of chess. Imagine a thought experiment on a chess game between a behaviour-based system and an existing chess computer. The chess computer would be unbeatable with the defined rules, but if the rules were modified the behaviour-based system may do better.

Threatening the rubber hand illusion..cortical anxiety

Ehrsson et al. report an interesting extension of work on illusory feelings of body ownership:

The feeling of body ownership is a fundamental aspect of self-consciousness. The underlying neural mechanisms can be studied by using the illusion where a person is made to feel that a rubber hand is his or her own hand by brushing the person's hidden real hand and synchronously brushing the artificial hand that is in full view. Here we show that threat to the rubber hand can induce a similar level of activity in the brain areas associated with anxiety and interoceptive awareness (insula and anterior cingulate cortex) as when the person's real hand is threatened. We further show that the stronger the feeling of ownership of the artificial hand, the stronger the threat-evoked neuronal responses in the areas reflecting anxiety. Furthermore, across subjects, activity in multisensory areas reflecting ownership predicted the activity in the interoceptive system when the hand was under threat. Finally, we show that there is activity in medial wall motor areas, reflecting an urge to withdraw the artificial hand when it is under threat. These findings suggest that artificial limbs can evoke the same feelings as real limbs and provide objective neurophysiological evidence that the rubber hand is fully incorporated into the body. These findings are of fundamental importance because they suggest that the feeling of body ownership is associated with changes in the interoceptive systems.

Figure legend - Linear relationship between ownership and the anxiety responses in the bilateral anterior insula and bilateral ACC (circled). A regression analysis identified a significant relationship between the vividness ratings of the rubber-hand illusion obtained during the scans and the parameter estimates for the contrast between threat during ownership and threat during no ownership in left insula

Embodying emotion

This is the title of an interesting review by Niedenthal (PDF here) on how manipulations of facial expression and posture in the laboratory can influence how emotions are processed. Whether we are similing or frowning, or hunched over or upright, can profoundly influence our emotional reactions to positive or negative input. Here is the abstract:

Recent theories of embodied cognition suggest new ways to look at how we process emotional information. The theories suggest that perceiving and thinking about emotion involve perceptual, somatovisceral, and motoric reexperiencing (collectively referred to as "embodiment") of the relevant emotion in one's self. The embodiment of emotion, when induced in human participants by manipulations of facial expression and posture in the laboratory, causally affects how emotional information is processed. Congruence between the recipient's bodily expression of emotion and the sender's emotional tone of language, for instance, facilitates comprehension of the communication, whereas incongruence can impair comprehension. Taken all together, recent findings provide a scientific account of the familiar contention that "when you're smiling, the whole world smiles with you."

Two ways in which facial expression has been manipulated in behavioral experiments. (Top) In order to manipulate contraction of the brow muscle in a simulation of negative affect, researchers have affixed golf tees to the inside of participants' eyebrows. Participants in whom negative emotion was induced were instructed to bring the ends of the golf tees together, as in the right panel. [Photo credit: Psychology Press]. (Bottom) In other research, participants either held a pen between the lips to inhibit smiling, as in the left panel, or else held the pen between the teeth to facilitate smiling.

A neural link between hand muscle excitability and numerical counting

Sato et al. do an interesting experiment showing that excitability of our hand muscles changes when we perform a visual (non-numerical) counting task, reinforcing the idea that finger counting represents an basic embodied strategy for number learning. (PDF here.) Their abstract:

Developmental and cross-cultural studies show that finger counting represents one of the basic number learning strategies. However, despite the ubiquity of such an embodied strategy, the issue of whether there is a neural link between numbers and fingers in adult, literate individuals remains debated. Here, we used transcranial magnetic stimulation to study changes of excitability of hand muscles of individuals performing a visual parity judgment task, a task not requiring counting, on Arabic numerals from 1 to 9. Although no modulation was observed for the left hand muscles, an increase in amplitude of motor-evoked potentials was found for the right hand muscles. This increase was specific for smaller numbers (1 to 4) as compared to larger numbers (6 to 9). These findings indicate a close relationship between hand/finger and numerical representations.

Motor cortex for the hand and numerical counting

The April 2007 issue of the Journal of Cognitive Neuroscience has interesting articles on this topic by Andres et al. and Sato et al. Their abstracts:

Andres et al.

The finding that number processing activates a cortical network partly overlapping that recruited for hand movements has renewed interest in the relationship between number and finger representations. Further evidence about a possible link between fingers and numbers comes from developmental studies showing that finger movements play a crucial role in learning counting. However, increased activity in hand motor circuits during counting may unveil unspecific processes, such as shifting attention, reciting number names, or matching items with a number name. To address this issue, we used transcranial magnetic stimulation to measure changes in corticospinal (CS) excitability during a counting task performed silently and using either numbers or letters of the alphabet to enumerate items. We found an increased CS excitability of hand muscles during the counting task, irrespective of the use of numbers or letters, whereas it was unchanged in arm and foot muscles. Control tasks allowed us to rule out a possible influence of attention allocation or covert speech on CS excitability increase of hand muscles during counting. The present results support a specific involvement of hand motor circuits in counting because no CS changes were found in arm and foot muscles during the same task. However, the contribution of hand motor areas is not exclusively related to number processing because an increase in CS excitability was also found when letters were used to enumerate items. This finding suggests that hand motor circuits are involved whenever items have to be put in correspondence with the elements of any ordered series.

Sato et al.

Developmental and cross-cultural studies show that finger counting represents one of the basic number learning strategies. However, despite the ubiquity of such an embodied strategy, the issue of whether there is a neural link between numbers and fingers in adult, literate individuals remains debated. Here, we used transcranial magnetic stimulation to study changes of excitability of hand muscles of individuals performing a visual parity judgment task, a task not requiring counting, on Arabic numerals from 1 to 9. Although no modulation was observed for the left hand muscles, an increase in amplitude of motor-evoked potentials was found for the right hand muscles. This increase was specific for smaller numbers (1 to 4) as compared to larger numbers (6 to 9). These findings indicate a close relationship between hand/finger and numerical representations.

The End Of The 'Natural'

This stimulating essay by Andy Clark I pass on in its entirety:

I am optimistic that the human race will continue to find ways of enhancing its own modes of thought, reason, and feeling. As flexible adaptive agents we are wide open to a surprising variety of transformative bodily and mental tricks and ploys, ranging from the use of software, sports regimes and meditational practice, to drug therapies, gene therapies, and direct brain-machine interfaces.

I am optimistic that, stimulated by this explosion of transformative opportunities, we will soon come to regard our selves as constantly negotiable collection of resources, easily able to straddle and criss-cross the boundaries between biology and artifact. In this hybrid vision of our own humanity I see increased potentials not just for repair but for empowerment, expansion, recreation, and growth. For some, this very same hybrid vision may raise specters of coercion, monstering and subjugation. For clearly, not all change is for the better, and hybridization (however naturally it may come to us) is neutral rather than an intrinsic good. But there is cause for (cautious) optimism.

First, there is nothing new about human enhancement. Ever since the dawn of language and self-conscious thought, the human species has been engaged in a unique 'natural experiment' in progressive niche construction. We engineer our own learning environments so as to create artificial developmental cocoons that impact our acquired capacities of thought and reason. Those enhanced minds then design new cognitive niches that train new generations of minds, and so on, in an empowering spiral of co-evolving complexity. The result is that, as Herbert Simon is reputed to have said, 'most human intelligence is artificial intelligence anyway'. New and emerging technologies of human cognitive enhancement are just one more step along this ancient path.

Second, the biological brain is itself populated by a vast number of hidden 'zombie processes' that underpin the skills and capacities upon which successful behavior depends. There are, for example, a plethora of such unconscious processes involved in activities from grasping an object all the way to the flashes of insight that characterize much daily skilful problem-solving. Technology and drug based enhancements add, to that standard mix, still more processes whose basic operating principles are not available for conscious inspection and control. The patient using a brain-computer interface to control a wheelchair will not typically know just how it all works, or be able to reconfigure the interface or software at will. But in this respect too, the new equipment is simply on a par with much of the old.

Finally, empirical science is at last beginning systematically to address the sources and wellsprings of human happiness and human flourishing, and the findings of these studies must themselves be taken as important data points for the design and marketing of (putative) technologies of enhancement.

In sum, I am optimistic that we will soon see the end of those over-used, and mostly ad hoc, appeals to the 'natural'...

Language, embodiment, and the cognitive niche

This is the title of an essay by Andy Clark in Trends in Cognitive Sciences (Vol 10, no. 8., pp. 370-374, 2006). It discusses an alternatives to the "Pure Translation" view, stemming from Fodor, that knowing a natural language is knowing how to pair its expressions with encoding in some other, more fundamental inner code ('mentalese', or the Language of Thought). Rather language is viewed as a kind of self-constructed cognitive niche, a scaffold of words that is used to loop back upon itself to build the "thinking about thinking" that may be our best candidate for a distinctively human capacity, dependent upon language for its very existence. According to this model words and structured linguistic encoding act to stabilize and discipline (or 'anchor') intrinsically fluid and context-sensitive modes of thought and reason. Words and linguistic strings are among the most powerful and basic tools that we use to discipline and stabilize dynamic processes of reason and recall. Words, rather than being cues for the retrieval of meanings from some kind of passive storage, might be thought of as sensorily encountered items that 'act directly on mental states'. As embodied agents we are able to create and maintain a wide variety of cognitively empowering, self-stimulating loops whose activity is as much as aspect of our thinking as its result.

Looking beyond the Pure Translation view, language is treated as an aspect of thought, rather than just its public reflection. We eliminate the Central Executive where all the 'real thinking' happens and replace Pure Translation with an appeal to complex, distributed coordination dynamics: a 'wordful mind' that is populated by loops without leaders, that defies any simple logic of inner versus out, or of tool versus user... a mind where words really work.

The Neural Basis of Embodyment

Some edited clips from a recent J. Neuroscience article by Arzy et al. :

Embodiment, the sense of being localized within one's physical body, is a fundamental aspect of the self. Recent evidence has started to show that self and body processing require two distinct brain mechanisms, with key loci in the temporoparietal junction (TPJ) - involved in self processing and multisensory integration of body-related information - and the extrastriate body area (EBA) - which responds selectively to human bodies and body parts. Arzy et al have used evoked potential mapping to show that activations in EBA and TPJ code differentially for embodiment and self location, because the location and timing of brain activation depended on whether mental imagery is performed with mentally embodied (EBA) or disembodied (TPJ) self location. In a second experiment, they showed that only EBA activation, related to embodied self location, but not TPJ activation, related to disembodied self location, was modified by the subjects' body position during task performance (supine or sitting). This suggests that embodied self location and actual body location share neural mechanisms.


Figure. To investigate embodiment and self location, subjects were asked to perform two mental-imagery tasks with respect to their own body in response to a schematic front- or back-facing human figure. In an own-body transformation task, (OBT task) subjects were asked to imagine themselves in the position and orientation of a schematic human figure, as shown on a computer screen (bottom row, the correct responses for each task are indicated under each stimulus) Either the right or left hand of the figure was marked, and subjects indicated which hand was marked. In a mirror task (MIR task), the same schematic human figure was shown, but subjects were instructed to imagine that the schematic figure (as shown on the computer screen) was their mirror reflection, as seen from their habitual point of view ( top row, the correct responses for each task are indicated under each stimulus).


Figure. Generators of mirror task (MIR. top row, were localized at the left EBA and of the own body transformation task (OBT, bottom row) at the right TPJ and left EBA


Figure. EBA. The mean (x, y) Talairach coordinates of the EBA are given for several neuroimaging studies. Note the similarity of EBA localization across studies, neuroimaging techniques, and behavioral tasks.

Left Brain and Right Brain in the regulation of our subjective feelings.

There is increasing evidence that an the insula areas of our left and right cerebral cortices process higher order re-representations of homeostatic (body regulatory) senses which are sent to prefrontal cortical areas and are the site of our subjective feelings about our bodies. (i.e., sensory information about our bodies from sympathetic and parasympathetic systems feeds to the insula and then on to the prefrontal cortex).

I'm including here quotes from a recent proposal by Craig in Trends in Cognitives Sciences (vol 9,pg. 566,2005) that tries to link many disparate threads to cast an integrated model of how basic regulatory levels of energy expenditure or storage regulated by the sympathetic and parasympathetic nervous systems though out our bodies connect to our higher levels of frontal lobe cognition. His proposal "highlights emerging evidence in support of a direct neuroanatomical relationship in the human forebrain between emotion and homeostasis that mirrors the asymmetric opponent management of energy acquisition and utilization by the autonomic nervous system."

"Recent neurobiological studies using anatomical, neurological, and functional imaging methods indicate that subjectively experienced feelings and emotions might be based on higher-order re-representations of homeostatic afferent (sensory) activity in the human forebrain, and it is particularly noteworthy that such evidence indicates a strong pattern of lateralization. Further, there is a comparable pattern of lateralization evident for the cortical control of cardiac activity, and this can be directly related to left/right asymmetry in the opposing parasympathetic and sympathetic components of the peripheral autonomic nervous system. The confluence of these strikingly parallel asymmetries suggests a homeostatic neuroanatomical model of emotional asymmetry, in which the left forebrain is associated predominantly with parasympathetic activity, and thus with nourishment, safety, positive affect, approach (appetitive) behavior, and group-oriented (affiliative) emotions, while the right forebrain is associated predominantly with sympathetic activity, and thus with arousal, danger, negative affect, withdrawal (aversive) behavior, and individual-oriented (survival) emotions. In the model I am proposing, management of physical and mental (meaning neural) energy is the salient organizational motif, such that energy enrichment is associated with the left forebrain and energy expenditure is associated with the right forebrain, consistent with the respective roles of the parasympathetic and sympathetic efferent systems. The autonomic principle of coordinated opponent interactions between the two hemispheres could provide a fundamental management process."

Figure: Imaging activity in the insula. Credit Univ. of Cambridge Center for Speech and Language.

Seeing as a way of acting.

I want to point out an accessible and fascinating web lecture with dynamic visual examples that outlines how we mentally construct our visual world (as well as the world interpreted through our other senses). The common view is that seeing is making an internal representation in our brains. O'Regan's new view is that seeing is knowing about things to do. This will make sense to you if you scan through O'Regan's very accessible introduction to the basic experiments and ideas: "Experience is not something we feel but something we do: a principled way of explaining sensory phenomenology, with Change Blindness and other empirical consequences."

One quote from the essay:
"In neuroscience today, one of the problems people are grappling with is to try to understand how a physical entity like a brain can give rise to something like the feeling of seeing, which is patently not physical.

Some as yet unknown mysterious, possibly even nonphysical mechanism has to be postulated to instill experience into the brain. But under the new view, the problem disappears, because experience is not in the brain at all.

It's in the doing of the exploration, and in the knowledge of the things that will change as you explore. Instead of the role of the brain being to generate the experience of seeing, the role of the brain simply becomes that of generating the exploratory activity which underlies the seeing, and that of holding the knowledge of current possibilities for action that underlies seeing.

Thus, the problem of finding a mechanism to generate experience in the brain disappears."

O'Regan's website provides links to his other work, and includes some excellent change blindness demonstrations, as well as a link to download his 2001 magnum opus in Behavioral and Brain Sciences.