Seeing who we hear and hearing who we see

In an article with the title of this post Seyfarth and Cheney make the following comments on work by Proops et al.

Imagine that you're working in your office and you hear two voices outside in the hallway. Both are familiar. You immediately picture the individuals involved. You walk out to join them and there they are, looking exactly as you'd imagined. Effortlessly and unconsciously you have just performed two actions of great interest to cognitive scientists: cross-modal perception (in this case, by using auditory information to create a visual image) and individual recognition (the identification of a specific person according to a rich, multimodal, and individually distinct set of cues, and the placement of that individual in a society of many others). Proops, McComb, and Reby show that horses do it, too, and just as routinely, without any special training. The result, although not surprising, is nonetheless the first clear demonstration that a non-human animal recognizes members of its own species across sensory modalities. It raises intriguing questions about the origins of conceptual knowledge and the extent to which brain mechanisms in many species—birds, mammals, as well as humans—are essentially multisensory.

According to a traditional view, multisensory integration takes place only after extensive unisensory processing has occurred. Multimodal (or amodal) integration is a higher-order process that occurs in different areas from unimodal sensory processing, and different species may or may not be capable of multisensory integration...An alternative view argues that, although different sensory systems can operate on their own, sensory integration is rapid, pervasive, and widely distributed across species. The result is a distributed circuit of modality-specific subsystems, linked together to form a multimodal percept...A third view argues that many neurons are multisensory, able to respond to stimuli in either the visual or the auditory domain (for example), and capable of integrating sensory information at the level of a single neuron as long as the two sorts of information are congruent. As a result, “much, if not all, of neocortex is multisensory”. By this account, perceptual development does not occur in one sensory modality at a time but is integrated from the start.

Here is the experiment as described in the Proops et al. abstract:

...we use a cross-modal expectancy violation paradigm to provide a clear and systematic demonstration of cross-modal individual recognition in a nonhuman animal: the domestic horse. Subjects watched a herd member being led past them before the individual went of view, and a call from that or a different associate was played from a loudspeaker positioned close to the point of disappearance. When horses were shown one associate and then the call of a different associate was played, they responded more quickly and looked significantly longer in the direction of the call than when the call matched the herd member just seen, an indication that the incongruent combination violated their expectations. Thus, horses appear to possess a cross-modal representation of known individuals containing unique auditory and visual/olfactory information. Our paradigm could provide a powerful way to study individual recognition across a wide range of species.

Eating dirt is good for you.

I have always attributed my robust immune system (I don't get colds) to the fact that when I was 1-5 years old I was crawling or running around barefoot in the hot Texas summer, eating dirt, pill bugs, and dog shit. Brody does a nice summary of what is now the accepted view: that exposure while young to a diverse array of bacteria, viruses, and worms trains the immune system in what is and is not important, essentially programs it for later adult life. Children raised in super hygiene environments are more likely to develop allergies, asthma, and autoimmune disorders.

Seeing ourselves as eddies in the stream of entropy

Of the hundreds of essays written to commemorate the 200th anniversary of Charles Darwin's birth, I think one of the most engaging is offered by Matt Ridley in the Spectator magazine. A few clips:

Living beings are eddies in the stream of entropy. That is to say, while the universe gradually becomes more homogeneous and disordered, little parts of it can reverse the trend and become briefly more ordered and complex by capturing packets of energy. It happens each time a baby is conceived. Built by 20,000 genes that turn each other on and off in a symphony of great precision, and equipped with a brain of ten trillion synapses, each refined and remodeled by early and continuing experience, you are a thing of exquisite neatness, powered by glucose. Says Darwin, this came about by bottom-up emergence, not top-down dirigisme. Faithful reproduction, occasional random variation and selective survival can be a surprisingly progressive and cumulative force: it can gradually build things of immense complexity. Indeed, it can make something far more complex than a conscious, deliberate designer ever could: with apologies to William Paley and Richard Dawkins, it can make a watchmaker.

Malthus taught Darwin the bleak lesson that overbreeding must end in pestilence, famine or violence — and hence gave him the insight that in a struggle for existence, survival could be selective. But the notion that, with random variation, this selective survival could then generate complexity and sophistication where there had been none before, that it is a cumulative and creative force, is entirely his. It is also one that applies to more than the bodies of living beings.

Technology is a case in point. Although engineers are under the fond illusion that they design things, nearly all of what they do consists of nudging forward descent with modification. Every technology has traceable ancestry; ‘to create is to recombine’ said the geneticist François Jacob. The first motor car was once described by the historian L.T.C. Rolt as ‘sired by the bicycle out of the horse carriage’. Just like living systems, technologies experience mutation (such as the invention of the spinning jenny), reproduction (the rapid mechanisation of the cotton industry as manufacturers copied each others’ machines), sex (Samuel Crompton’s combination of water frame and jenny to make a ‘mule’), competition (different designs competing in the early cotton mills), extinction (the spinning jenny was obsolete by 1800), and increasing complexity (modern cotton mills are electrified and computerised).

Software inventors have learnt to recognise the power of trial and error rather than deliberate design. Beginning with ‘genetic algorithms’ in the 1980s, they designed programmes that would experiment with changes in their sequence till they solved the problem set for them. Then gradually the open-source software movement emerged by which users themselves altered programmes and shared their improvements with each other. Linux and Apache are operating systems designed by such democratic methods, but the practice has long spread beyond programmers. Wikipedia is a bottom-up knowledge repository and, though far from flawless, is proving easily capable, even in its first flush of youth, of matching expert-written encyclopaedias for accuracy and reach. It grows by natural selection among edits.

The internet is an increasingly Darwinian place, where decentralised, self-organising sophistication holds sway: swarm intelligence is the fashionable term. Trey Ratcliff, founder of a computer games company in Texas, tells me he feels more like a victim than a designer of technology’s evolution: ‘saying Edison invented the phonograph is like saying a spider invented silk’.

The Machine Stops

A large component of the current financial meltdown results from people trusting that they were being cared for by complex financial instruments that neither they nor the people who designed them really understood. It recently struck me that this sort of situation was described long ago by E.M Forster in his prescient 1909 science fiction short story "The Machine Stops." I found the text here and very much enjoyed re-reading the story. A synopsis is given by the wikipedia entry, and it can be downloaded in the various electronic formats.

MindBlog does a gig on a happiness webcast/podcast

With some trepidation I signed on to be a talking head neuroscience 'expert' on the "Make Me Happy!" Radio Show with Drs. Aymee Coget and Bob Nozik as hosts last Friday, 4-5 p.m. pacific time. The one hour show is podcast until this friday at www.AdviceRadio.com, or you can download the .mp3 file here. My interview starts 7 1/2 minutes into the program after a somewhat loopy new-agey california-style introduction. I just listened to the first few minutes of the interview, and I guess it is OK, although I'm pained that the number of "uh's" and "y'knows" is right up there with Caroline Kennedy's. I should mention to those of you who responded to my 'would you like some podcasts from MindBlog?' question affirmatively that my intentions are still good, but I just haven't found time to actually start doing them. Doing these postings and also keeping up piano performance and chamber music seems to take up more time than I have.

A new kind of mind.

In response to this years Edge question "What would change everything - What game-changing scientific ideas and developments do you expect to live to see?", Kevin Kelly sees a new kind of cheap, powerful, ubiquitous artificial intelligence, the kind of synthetic mind that learns and improves itself.

...the snowballing success of Google this past decade suggests the coming AI will not be bounded inside a definable device. It will be on the web, like the web. The more people that use the web, the more it learns. The more it knows, the more we use it. The smarter it gets, the more money it makes, the smarter it will get, the more we will use it. The smartness of the web is on an increasing-returns curve, self-accelerating each time someone clicks on a link or creates a link. Instead of dozens of geniuses trying to program an AI in a university lab, there are billion people training the dim glimmers of intelligence arising between the quadrillion hyperlinks on the web. Long before the computing capacity of a plug-in computer overtakes the supposed computing capacity of a human brain, the web—encompassing all its connected computing chips—will dwarf the brain. In fact it already has.

When this emerging AI, or ai, arrives it won't even be recognized as intelligence at first. Its very ubiquity will hide it. We'll use its growing smartness for all kinds of humdrum chores, including scientific measurements and modeling, but because the smartness lives on thin bits of code spread across the globe in windowless boring warehouses, and it lacks a unified body, it will be faceless. You can reach this distributed intelligence in a million ways, through any digital screen anywhere on earth, so it will be hard to say where it is. And because this synthetic intelligence is a combination of human intelligence (all past human learning, all current humans online) and the coveted zip of fast alien digital memory, it will be difficult to pinpoint what it is as well. Is it our memory, or a consensual agreement? Are we searching it, or is it searching us?

Most downloaded consciousness papers of 2008

The ASSC (Association for the Scientific Study of Consciousness) keeps an eprints archive from which you can download a large number of papers. They report the following as the most downloaded papers of 2008:

Metacognition and Consciousness, Koriat, A. (2006) In: Cambridge handbook of consciousness. Cambridge University Press, New York, USA. http://eprints.assc.caltech.edu/175/ 15281 downloads from 57 countries

Methods for studying unconscious learning, Destrebecqz, Arnaud and Peigneux, Philippe (2005) In: Progress in Brain Research. Elsevier, pp. 69-80. http://eprints.assc.caltech.edu/170/ 14015 downloads from 64 countries

Crossmodal interactions: lessons from synesthesia, Sagiv, Noam and Ward, Jamie (2006) In: Visual Perception, Part 2 - Fundamentals of Awareness: Multi-Sensory Integration and High-Order Perception. Progress in Brain Research, Volume 155. Elsevier, pp. 259-271. ISBN 0444519270 http://eprints.assc.caltech.edu/224/ 13193 downloads from 43 countries

Inverse Zombies, Anesthesia Awareness, and the Hard Problem of Unconsciousness, Mashour, George A. (2007) In: 11th Annual Meeting of the ASSC, Las Vegas. http://eprints.assc.caltech.edu/294/ 11421 downloads from 69 countries

Conscious, preconscious, and subliminal processing: a testable taxonomy, Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel and Sackur, Jérôme and Sergent, Claire (2006) Trends in Cognitive Science, 10 (5). pp. 204-211. http://eprints.assc.caltech.edu/20/ 10094 downloads from 51 countries

Getting the dead to talk back.

In his January Scientific American column, "Skeptic", Michael Shermer writes about his experience as the token scientist invited to Univ-Con, a paranormal conference organized by Ryan Buell, the telegenic host of A&E’s television unreality series Paranormal State.

“Is Matthew there?” asked Cheyenne, directing her voice toward the box on the table in hopes that her brother would come through from the other side. “Yes,” the reply came. With the connection “validated,” Cheyenne shakily continued: “Was the suicide a mistake?” The speaker crackled, “My death was a mistake.”... Cheyenne’s life-affirming messages were coming out of Thomas Edison’s “Telephone to the Dead”—or at least a facsimile of a rumored machine that the great inventor never built. It was just one of many readings that day (at $90 a pop) conducted by Christopher Moon, senior editor and president of Haunted Times magazine.

I couldn’t hear Cheyenne’s brother, mother or any other incorporeal spirits, until Moon interpreted the random noises emanating from the machine that, he explained to me, was created by a Colorado man named Frank Sumption. “Frank’s Box,” according to its inventor, “consists of a random voltage generator, which is used to tune an AM receiver module rapidly. The audio from the tuner (“raw audio”) is amplified and fed to an echo chamber, where the spirits manipulate it to form their voices.” Apparently doing so is difficult for the spirits, so Moon employs the help of “Tyler,” a spirit “technician,” whom he calls on to corral wayward spirits to within earshot of the receiver. What it sounded like was the rapid twirling of a radio dial so that only noises and word fragments were audible.

“Well, since we know how easy it is for our brains to find meaningful patterns in meaningless noise,” I continued, “how can you tell the difference between a dead person’s real words and the random noises that just sound like words?” Moon agreed, “You have to be very careful. We record the sessions and get consistency in what people hear.” I persisted: “Consistency, as in what, 95 percent, 51 percent?” “A lot,” Moon rejoined.

That evening in my keynote address I explained how “priming” the brain to see or hear something increases the likelihood that the percepts will obey the concepts. I played a part of Led Zeppelin’s Stairway to Heaven backwards, in which one can hear an occasional “Satan,” and then played it again after priming their brains with the alleged lyrics on the screen. The auditory data jumped off the visual cues (the funniest being “there was a little toolshed where he made us suffer, sad Satan”—see it in my lecture “Skepticism 101” at www.skeptic.com). I also played a number of auditory illusions produced by psychologist Diana Deutsch of the University of California, San Diego (http://deutsch.ucsd.edu/), in which a repetitive tape loop of a two-syllable word educes different words and phrases in different people’s minds. These are examples of patternicity, the tendency to find meaningful patterns in meaningless noise (a concept I introduced in my December 2008 column), and the next day I put it to the test when Moon gave me a personal demo. With the Telephone to the Dead squawking away, I tried to connect to my deceased father and mother, asking for any “validation” of a connection—name, cause of death ... anything. I coaxed and cajoled. Nothing. Moon asked Tyler to intervene. Nothing. Moon said he heard something, but when I pressed him he came up with nothing. I willingly suspended my disbelief in hopes of talking to my parents, whom I miss dearly. Nothing. I searched for any pattern I might find. Nothing.

And that, I’m afraid, is my assessment of the paranormal. Nothing.

Predicting risk taking

From Gianotti et al., who performed EEG measurements on forty right-handed female students at the Univ. of Zurich:

Human risk taking is characterized by a large amount of individual heterogeneity. In this study, we applied resting-state electroencephalography, which captures stable individual differences in neural activity, before subjects performed a risk-taking task. Using a source-localization technique, we found that the baseline cortical activity in the right prefrontal cortex predicts individual risk-taking behavior. Individuals with higher baseline cortical activity in this brain area display more risk aversion than do other individuals. This finding demonstrates that neural characteristics that are stable over time can predict a highly complex behavior such as risk-taking behavior and furthermore suggests that hypoactivity in the right prefrontal cortex might serve as a dispositional indicator of lower regulatory abilities, which is expressed in greater risk-taking behavior.

Some clarity on alternative therapies and medical science

Mindblog reader Ian has pointed me to this essay on alternative medicine and new age spirituality by Bruce Charlton, at the University of Newcastle upon Tyne. His website contains other interesting bits of writing. He paints what I think should be a useful and clear distinction:

I would define alternative therapies in terms of them having non-scientific explanations. In so far as a therapy does have a biological explanation, I would regard that therapy as simply part of orthodox medicine. The crucial difference between orthodox and alternative therapies is therefore that alternative medical systems have non-scientific explanations based on spiritual, mystical, legendary or otherwise intuitively-appealing insights...I am broadly supportive of alternative and complementary therapies because I think that overall they do a great deal of good for a large number of people. But the kind of good they do is psychological and spiritual; not medical. They are about making people feel better (‘healing’) not mending their dysfunctional brains and bodies (‘curing’). Alternative therapies certainly are not a part of medical science. So, on the one hand, I would like to see alternative therapies thrive and spread, and on the other hand they should drop all their pretensions to ‘scientific’ validity. In future, alternative medicine should explicitly become part of New Age spirituality, and thereby clearly be differentiated from orthodox medicine and biological science.

He argues against the relevance of randomized trials to test alternative therapies:

...when randomised trials are used in alternative medicine, the usual process of therapeutic development is turned on-its-head. Instead of coming at the end of a long process of scientific evaluation, randomized trials are placed at the beginning of evaluation, and are indeed expected to be the only form of scientific evaluation – with randomization used in isolation with no possibility for cross-checking using other scientific methods...The problem is not so much that alternative therapy systems are scientifically primitive; it is that alternative systems are not scientific at all. By definition they do not have scientifically-grounded explanations. When the constraints of randomized trials are properly understood, it becomes clear that 'positive' trials in alternative medicine are irrelevant.

His summary:

Orthodox medicine is based on scientific theories and is properly characterized by objective evaluation criteria and formal professional structures of education and certification. Alternative healing deploys a wide range of intuitively-appealing but non-scientific explanations, and constitutes a consumer-dominated marketplace of ideas and therapies which are personally-evaluated by the client...Orthodox medicine focuses on curing disease and promoting health. But alternative therapies should be based on promoting well-being and personal fulfillment. To do this they need to be able freely to deploy poetic explanations and charismatic healers as part of the wide and growing practice of New Age spirituality.

Prosopagnosia due to reduced cortical connectivity

Prosopagnosics have impaired face recognition, but make relatively normal responses to face stimuli in core brain regions for face recognition. Thomas et. al find that it is the connectivity among these regions that is being disrupted in the disorder:

Using diffusion tensor imaging and tractography, we found that a disruption in structural connectivity in ventral occipito-temporal cortex may be the neurobiological basis for the lifelong impairment in face recognition that is experienced by individuals who suffer from congenital prosopagnosia. Our findings suggest that white-matter fibers in ventral occipito-temporal cortex support the integrated function of a distributed cortical network that subserves normal face processing.

Sex, sweat and your brain

From Zou and Chen, showing that two areas of women's brains respond to chemical signals in the sweat of sexually aroused men. Their edited abstract, and a figure:

Chemosensory communication of affect and motivation is ubiquitous among animals. In humans, emotional expressions are naturally associated with faces and voices. Whether chemical signals play a role as well has hardly been addressed. Here, we use functional magnetic resonance imaging to show that the right orbitofrontal cortex, right fusiform cortex, and right hypothalamus respond to airborne natural human sexual sweat (distinguishing it from neutral sweat, and a nonsocial control), indicating that this particular chemosensory compound is encoded holistically in the brain. Interestingly, with the exception of hypothalamus, neither the OFC nor the fusiform region is implicated in sexual motivation and behavior. Hence, our results implied that the chemosensory information from natural human sexual sweat was encoded more holistically in the brain rather than specifically for its sexual quality. Our findings provide neural evidence that socioemotional meanings, including the sexual ones, are conveyed in the human sweat.

Figure - Brain responses to social chemosensory compounds. a, Coronal view showing an activated area in the right orbitofrontal cortex. d. Sagittal view showing an activated region in the right fusiform gyrus.

(I might as well also repeat this link from a post several days ago, on the debate raging over MRI studies of social cognition that has been started off by a paper titled "Voodoo correlations in social neuroscience".)

Why we hiccup.

An article by Neil Shubin in the January Scientific American notes how a number of evolutionary hand-me-downs inherited from fish and tadpoles have left us with hernias, hiccups and other maladies. I thought this bit on why we hiccup was fascinating: it is because we once were tadpoles.

A spasm of the muscles in the throat and chest causes a hiccup. The characteristic “hic” sound results when we sharply inspire air while the epiglottis, a flap of soft tissue at the back of the throat, closes. All these movements are completely involuntary; we “hic” without any thought on our part. Hiccups occur for many reasons: we eat too fast or too much; even more severe conditions, such as tumors in the chest area, can bring them on. Hiccups reveal at least two layers of our history: one shared with fish, another with amphibians, according to one well-supported hypothesis. We inherited the major nerves we use in breathing from fish. One set of nerves, the phrenic, extends from the base of the skull and travels through the chest cavity and the diaphragm, among other places. This tortuous course creates problems; anything that interrupts the path of these nerves along their length can interfere with our ability to breathe. Irritation of these nerves can even be a cause of hiccups. A more rational design of the human body would have the nerves traveling not from the neck but from a spot nearer to the diaphragm. Unluckily, we became heir to this design from fishy ancestors with gills closer to the neck, not a diaphragm well below it. If the strange pathway of the nerves is a product of our fish origin, the hiccup itself may have arisen from the past we share with amphibians. It turns out that the characteristic pattern of muscle and nerve activity of hiccups occurs naturally in other creatures. And not just any creatures. More specifically, they turn up in tadpoles that use both lungs and gills to breathe. When tadpoles use their gills, they have a problem— they need to pump water into their mouth and throat and then across the gills, but they need to keep this water from entering their lungs. So what do they do? They shut the glottis to close off the breathing tube, while sharply inspiring. In essence, they breathe with their gills using an extended form of hiccup. (click on figure to enlarge it).

Species conservation - how being helpful hurts

Cornelia Dean makes note of a fact I had not thought much about. Conservation regulations that specify the minimum size of individuals that can be harvested, whether they be fish, bighorn sheep, or ginseng plants, increase the rate of evolution to favor smaller individuals that reproduce at an earlier age. This works against species health. Humans are harvesting mature adults, whereas natural predators would target smaller or weaker (old) individuals. Rates of evolutionary change are three times higher in species subject to “harvest selection” than in other species. Here is the abstract of Darimont et al.'s work.

Oxytocin makes a face in memory familiar

It is known that men treated with oxytocin perform better in inferring affective state from the eye region of human faces. Oxytocin also increases social behaviors like trust. Rimmele at al. show now that oxytocin delivered by a commercially available nasal spray (Syntocinon Spray from Novartis) selectively enhances memory encoding of faces in humans, but not of nonsocial stimuli. Here is their abstract:

Social recognition is the basis of all social interactions. Here, we show that, in humans, the evolutionarily highly conserved neuropeptide oxytocin, after intranasal administration, specifically improves recognition memory for faces, but not for nonsocial stimuli. With increased oxytocin levels, previously presented faces were more correctly assessed as "known," whereas the ability of recollecting faces was unchanged. This pattern speaks for an immediate and selective effect of the peptide strengthening neuronal systems of social memory.

Brain games for you, coming soon from Mattel

Justin Landwehr and PFSK point us to a concentration game coming from Mattel.

MRI of human social values?

I read something like this by Zahn et. al., and am fascinated at the same time I am wondering what the hell to make of it. (Here, by the way, is a disucssion of the debate raging over MRI studies of social cognition that has been started off by a paper titled "Voodoo correlations in social neuroscience".) My impression is that if you scan the MRI (magnetic resonance brain imaging) literature for all the functions that have been 'correlated with,' for example, the subgenual cingulate (in this case, guilt) or orbitofrontal-insular cortices (indignation, anger) you would find a hopelessly large list. Still, the prospect of stable neural architectures associated with different discrete social emotions is interesting. The authors suggest that social values emerge from coactivation of abstract conceptual representations within the anterior temporal lobe region (aTL, BA38/22), emotional states represented in mesolimbic and basal forebrain regions (hypothalamus, septum, VTA (ventral tegmental area), anterior insula) and emotion–action associations in OFC (orbitofrontal cortex) as well as sequential action outcomes in anterior medial PFC (prefrontal cortex) regions. They provide data...

...supporting a model in which social values draw upon stable representations of conceptual detail within the anterior temporal lobe region (aTL, BA38/22) and context-dependent representations of distinct moral sentiments within fronto-mesolimbic regions. They test a model of integration of the concepts and emotions that form social values in which social values change their emotional quality in a flexible way adapted to the context of agency. They suggest that a separation of stable context-independent representations in the aTL can be flexibly embedded within different contexts of action implementation and emotional qualities as encoded in fronto-limbic circuits to account for our ability to link social values to a wide range of interpersonal and cultural settings

The interdependency of context of actions and emotional evaluation has been a key component of the notion of values proposed by British philosophers during the 18th century. According to this stance, intuitive "moral sentiments" determine whether we perceive a behavior as constituting a virtue or vice and guide our approval or disapproval of that behavior...When we are the agent of an action conforming to our values, we may feel pride, whereas when another person is the agent, we may feel gratitude. On the negative side, when we act counter to our values, we may feel guilt and when another person acts in the same way toward us, we instead feel indignation or anger.

Here is the abstract of the paper:

Social values are composed of social concepts (e.g., "generosity") and context-dependent moral sentiments (e.g., "pride"). The neural basis of this intricate cognitive architecture has not been investigated thus far. Here, we used functional magnetic resonance imaging while subjects imagined their own actions toward another person (self-agency) which either conformed or were counter to a social value and were associated with pride or guilt, respectively. Imagined actions of another person toward the subjects (other-agency) in accordance with or counter to a value were associated with gratitude or indignation/anger. As hypothesized, superior anterior temporal lobe (aTL) activity increased with conceptual detail in all conditions. During self-agency, activity in the anterior ventromedial prefrontal cortex correlated with pride and guilt, whereas activity in the subgenual cingulate solely correlated with guilt. In contrast, indignation/anger activated lateral orbitofrontal-insular cortices. Pride and gratitude additionally evoked mesolimbic and basal forebrain activations. Our results demonstrate that social values emerge from coactivation of stable abstract social conceptual representations in the superior aTL and context-dependent moral sentiments encoded in fronto-mesolimbic regions. This neural architecture may provide the basis of our ability to communicate about the meaning of social values across cultural contexts without limiting our flexibility to adapt their emotional interpretation.

Finger length predicts successful financial trading!

This analysis by Coates et al. is a real hoot. They find that the second-to-fourth digit ratio predicts success among high-frequency financial traders:

Prenatal androgens have important organizing effects on brain development and future behavior. The second-to-fourth digit length ratio (2D:4D) has been proposed as a marker of these prenatal androgen effects, a relatively longer fourth finger indicating higher prenatal androgen exposure. 2D:4D has been shown to predict success in highly competitive sports. Yet, little is known about the effects of prenatal androgens on an economically influential class of competitive risk taking—trading in the financial world. Here, we report the findings of a study conducted in the City of London in which we sampled 2D:4D from a group of male traders engaged in what is variously called “noise” or “high-frequency” trading. We found that 2D:4D predicted the traders' long-term profitability as well as the number of years they remained in the business. 2D:4D also predicted the sensitivity of their profitability to increases both in circulating testosterone and in market volatility. Our results suggest that prenatal androgens increase risk preferences and promote more rapid visuomotor scanning and physical reflexes. The success and longevity of traders exposed to high levels of prenatal androgens further suggests that financial markets may select for biological traits rather than rational expectations.

Insults and joys of old age...

Dwight Garner offers a review of a recent book, "Somewhere towards the end," by former prominent London book editor, 91 year old Diana Athill. ( I regret that I - like many of you, I suspect - read more book reviews than actual books.) Here are some clips that I thought interesting:

A positive aspect of the waning of sex, Ms. Athill says, “was that other things became more interesting.” ... I was surprised that this longtime fiction editor has declared that she has “gone off novels.”...Why? She no longer feels the need to parse the intricacies of human relationships and love affairs, “but I do still want to be fed facts, to be given material which extends the region in which my mind can wander.” ...The elderly, she writes, can find great enjoyment in the company of younger people. But she warns: “One should never, never expect them to want one’s company, or make the kind of claims on them that one makes on a friend of one’s own age. Enjoy whatever they are generous enough to offer, and leave it at that.”

The book ends with her realization:

“There are no lessons to be learnt, no discoveries to be made, no solutions to offer. I find myself left with nothing but a few random thoughts. One of them is that from up here I can look back and see that although a human life is less than the blink of an eyelid in terms of the universe, within its own framework it is amazingly capacious so that it can contain many opposites. One life can contain serenity and tumult, heartbreak and happiness, coldness and warmth, grabbing and giving — and also more particular opposites such as a neurotic conviction that one is a flop and a consciousness of success amounting to smugness.”

The dead end of current economic models...

Here is a short and sweet statement of the futility of current models of economic recovery and growth, from a letter to the Nature editor from Hervé Philippe, a biochemist at the University of Montreal. It mirrors my own sentiment: that talk of 'restoring economic growth' in the absence of ruthless planning to achieve steady state sustainable energy fluxes on this planet is delusional.

...the prosperity [of Western societies] is mainly based on the use of non-renewable resources and therefore is probably spurious...Several hundred million years were needed to form the fossil energy that will be exhausted during a few hundred years. This is roughly equivalent to spending all one's annual income during the first 30 seconds of a year. In particular, the frenzy to automate processes in order to increase competitiveness leads to rapid exhaustion of available resources, for example through over-fishing or degradation of soils....All current growth-based economic models imply massive use of non-renewable resources and environmental degradation. These models are not sustainable, even in the short term....As early as 160 years ago, John Stuart Mill affirmed that "the richest and most prosperous countries would very soon attain the stationary state" (Principles of Political Economy Longmans, 1848). In contrast to that time, when resources were being used up at a rate that was several orders of magnitude slower than today, a phase of economic degrowth is necessary before a stationary state can be reached. It would be a major achievement of economics to achieve such a degrowth without social and political disasters.