The possibility of impossible cultures.

Marc Hauser offers an essay in the 9 July issue of Nature, in which he suggests points of contact between work in the generative tradition of linguistics (Chomsky, etc.) and evolutionary developmental biology research on animal forms. Just as a developing animal form faces a massive range of possible variation:

...children are born with the capacity to acquire a wide range of possible languages, as opposed to specific languages such as English, Korean or French. This implies that a child is equipped with an abstract acquisition device, allowing the 'growth' of many different languages. Furthermore, as the child's acquisition device generates a space of possible languages, something internal or external to the device creates a space of impossible languages — forms that are never entertained by the child because they are poorly designed for acquisition and externalization in linguistic communication.

...in the same way that biologists speak of morphospaces — n-dimensional volumes that define the range of existing and potential morphological variation — linguists can speak of 'linguaspaces'. These are n-dimensional environments that constrain the set of possible languages and therefore, by definition, establish the set of impossible languages. What is necessary, therefore, is to establish the set of parameters that allow the range of variation and place constraints on its overall form.

...a point of contact concerns how the internal language system ultimately forms an acquired and externalizable language. If, as discussed earlier, the acquisition device constrains the range of possible languages by providing a set of options, then the role of environmental input is to favour, and thus select, certain options over others. This selective perspective, although uncommon in the mind sciences, aligns more closely with other work in biology, including studies of the immune system, the development of animal forms, the wiring of neurons and the acquisition of bird song. For example, songbirds have evolved brains with a set of developmental options for creating variation in song-relevant acoustic forms. Depending on the environment, certain note types are selected and are then reproduced in particular orders to create population-specific dialects — and so it is for language acquisition by humans. When a child is exposed to a particular linguistic environment, the relevant linguistic input or experience fixes the available options to create an externalizable language that is comprehensible to those who will care for and compete with the child.

Research in the generative tradition of linguistics suggests therefore that, like the variety of animal forms, the sense of unbounded variation in linguistic form is illusory, concealing a suite of universally held, biologically instantiated mechanisms for generating variation, allowing acquisition and constraining the space of possible languages. Although biologists have long sensed the close connection between the generative properties of language and generative biological systems, including the immune system, microbial diversity and proteonomics (the study of protein function and expression) relatively few students of the mind sciences have acknowledged such connections with other domains of human knowledge.

Heuser suggests that only humans have evolved four computational capacities, constituting a phylogenetic mind gap between humans and other animals:

Generative computation Recursive and combinatorial operations provide the only known mechanisms for generating an almost limitless variety of meaningful expressions, whether mathematical, linguistic, musical or moral. Recursion is an iterative operation, in which a rule is called up repeatedly to create new expressions, be they embedded phrases within a sentence, new musical scores with repeating themes, or tools within tools (for example, a Swiss army knife). Each expression has a unique interpretation or function depending on the arrangement of the elements. By contrast, combinatorial operations allow discrete elements to be unified and ordered, thus creating new ideas, which could be expressed as novel words (Walkman from walk and man) or novel musical forms.

Mental symbols Humans readily, without instruction, convert sensory experiences and abstract thoughts into externalized symbols, either as words or images. This capacity cuts across domains of knowledge and sensory experience, enabling humans to express beliefs in sentences, to depict particular melodies with explicit notations, and to provide logos indicating when to turn off the highway for a hamburger or a coffee.

Promiscuous interfaces Humans have unique creative capacities and problem-solving abilities, which stem from the capacity to combine representations promiscuously from different domains of knowledge. For instance, humans can combine the concepts of number, belief, causality and harm in deciding that it is sometimes morally obligatory to harm one person to save the lives of many.

Abstract thought Some thoughts derive from direct sensory experiences: for example, thinking of red items such as cherries and blood requires experience with these, as opposed to non-red objects such as celery and bone. But many human thoughts are abstract, with no explicit or even necessary sensory connection. These include concepts such as infinity, grammatical categories such as nouns and verbs, and ethical judgments such as permissible and forbidden.



Figure - Promiscuous interfaces between different domains of knowledge. An example of deciding whether taking one life is justified if the action saves many other lives. A representation of an action (a finger pulling a trigger) interfaces with a representation of death as a potential consequence, which in turn interfaces with a system of numerical representation that evaluates whether the number of lives killed exceeds the number saved. This then interfaces with a moral evaluative system that judges the permissibility of the initial action, which then interfaces with the human linguistic system to deliver the judgement "forbidden".

The generative mechanisms that underpin so much of human mental life acquire their expressive power because the recursive and combinatorial operations can functionally 'grab' the outputs of different modular systems or domains of knowledge. This capacity for promiscuously creating interfaces between domains is almost absent in animals. Thus, although both human and animal brains are characterized by modular functions and mechanisms, the modular outputs are typically restricted to a single functional problem in animals but are broadly accessible in humans. Non-human animals therefore show a form of myopic intelligence, designed to solve one problem with exquisite efficiency. For example, although honeybees have a symbolic dance that indicates the distance, direction and quantity of food, this communication system is largely restricted to food despite the intricate social lives of bees. Although meerkat adults teach their pups how to kill scorpion prey by providing them with age-appropriate opportunities for handling and dismembering, teaching does not occur in any other context. Although plovers use a deceptive display to lure predators away from their nest of eggs, they do not deceive in any other situation. And although chimpanzees use the direction of another's eyes to guide strategic competition, they are far less skilled at using another's eyes to guide cooperation. By contrast, in humans, neither language, teaching, deception, or the use of seeing to infer knowing are restricted to a single context.

The evolution of misbelief

Below I paste in the abstract (and here is the PDF) of a forthcoming article in Brain and Behavioral Science by McKay and Dennett that examines possible evolutionary rationales for mistaken beliefs, bizarre delusions, instances of self-deception, etc. Of the range of potential candidates for evolved misbelief, they conclude that, among those surveyed, only positive illusions meet their criteria.

From an evolutionary standpoint, a default presumption is that true beliefs are adaptive and misbeliefs maladaptive. But if humans are biologically engineered to appraise the world accurately and to form true beliefs, how are we to explain the routine exceptions to this rule? How can we account for mistaken beliefs, bizarre delusions and instances of self-deception? We explore this question in some detail. We begin by articulating a distinction between two general types of misbelief: those resulting from a breakdown in the normal functioning of the belief formation system (e.g. delusions) and those arising in the normal course of that systems operations (e.g. beliefs based on incomplete or inaccurate information). The former are instances of biological dysfunction or pathology, reflecting culpable limitations of evolutionary design. Although the latter category includes undesirable (but tolerable) by-products of forgivably limited design, our quarry is a contentious subclass of this category: misbeliefs best conceived as design features. Such misbeliefs, unlike occasional lucky falsehoods, would have been systematically adaptive in the evolutionary past. Such misbeliefs, furthermore, would not be reducible to judicious but doxastically noncommittal - action policies. Finally, such misbeliefs would have been adaptive in themselves, constituting more than mere by-products of adaptively biased misbelief-producing systems. We explore a range of potential candidates for evolved misbelief, and conclude that, of those surveyed, only positive illusions meet our criteria.

EEG prediction of lapses in attention.

O'Connell et al. show that EEG signals can predict a forthcoming lapse in attention 20 seconds before it occurs. Could this prove useful for a task (like flying an airplane or operating complex but boring equipment) in which constant attention is required?

Feminize yourself by drinking bottled water....

Kristof does a piece on how the phthalates used in plastic manufacture, found now in our water supply and leached from many plastic bottle products, can nudge the development of humans and other animals towards feminization.

Melancholy...

Here's a haunting piece: from Grieg's Lyric Pieces, Op 47 No 5 - Melancholy
(I enjoy sitting down at the end of an afternoon and playing these brief Grieg pieces, and it takes only a modest effort to record them, using Apple's Garage Band and iMovie applications.)

A sixth sense...

A prosthesis that immerses you in the data world, described by Pattie Maes in a TED lecture.

Obamology

From the Random Samples section of the July 10 issue of Science:

Obamology

Hey, they never did this with George W. Bush! The American Sociological Association, meeting in San Francisco, California, in August, will be examining the presidency in-depth in sessions held under the heading "The Sociological Significance of President Barack Obama."

* Plenary Session: "Why Obama Won (and What that Says About Democracy and Change in America)"
* Presidential Panel: "A Defining Moment? Youth, Power and the Obama Phenomenon"
* Presidential Panel: "Through the Lens of Gender, Race, Sexuality and Class: The Obama Family and the American Dream"
* Thematic Session: "Understanding Democratic Renewal: The Movement to Elect Barack Obama"
* Thematic Session: "The Future of Community Organizing During an Obama Presidency"
* Thematic Session: "Asian-American Movements, Identities, and Politics: A New Racial Project in the Obama Years?"
* Open Forum: "Does the Obama Administration Need a Social Science Scholars Council?"

Narrowing of intersensory speech perception in infancy

From Pons et al.:

The conventional view is that perceptual/cognitive development is an incremental process of acquisition. Several striking findings have revealed, however, that the sensitivity to non-native languages, faces, vocalizations, and music that is present early in life declines as infants acquire experience with native perceptual inputs. In the language domain, the decline in sensitivity is reflected in a process of perceptual narrowing that is thought to play a critical role during the acquisition of a native-language phonological system. Here, we provide evidence that such a decline also occurs in infant response to multisensory speech. We found that infant intersensory response to a non-native phonetic contrast narrows between 6 and 11 months of age, suggesting that the perceptual system becomes increasingly more tuned to key native-language audiovisual correspondences. Our findings lend support to the notion that perceptual narrowing is a domain-general as well as a pan-sensory developmental process.

Racial group membership modulates empathic brain responses.

From Xu et al.:

The pain matrix including the anterior cingulate cortex (ACC) mediates not only first person pain experience but also empathy for others' pain. It remains unknown, however, whether empathic neural responses of the pain matrix are modulated by racial in-group/out-group relationship. Using functional magnetic resonance imaging we demonstrate that, whereas painful stimulations applied to racial in-group faces induced increased activations in the ACC and inferior frontal/insula cortex in both Caucasians and Chinese, the empathic neural response in the ACC decreased significantly when participants viewed faces of other races. Our findings uncover neural mechanisms of an empathic bias toward racial in-group members.


Figure - a, Illustration of Caucasian faces receiving painful and non-painful stimuli. b, Illustration of Chinese faces receiving painful and non-painful stimuli. c, Contrast values of the parameter estimates of signal intensity in the ACC and the frontal cortex that differentiated painful and non-painful stimuli in Caucasians. d, Contrast values of the parameter estimates of signal intensity in the ACC and the frontal cortex that differentiated painful and non-painful stimuli in Chinese. e, Correlation between ACC empathic neural responses to racial in-group and out-group members. X and Y axes respectively indicate ACC empathic responses to racial in-group and racial out-group members indexed in contrast values of painful versus non-painful stimulation. f, Increased activations in the ACC and the frontal/insula cortex shown in whole-brain statistical parametric mapping analyses when participants perceived racial in-group faces. The upper figures show the results from Caucasian subjects and the lower figures show the results from Chinese subjects.

Happiness is just around the corner!

I wish I were taking the same happy pill that Betsy Devine seems to have found... seems a bit Pollyanna to me...

Brain changes caused by encouraging expressions.

Martín-Loeches et al. find that encouraging and discouraging messages elicit a similar long-lasting brain emotional response during a visuospatial task. Further, encouraging expressions are able to alter the customary working pattern of the visual attention system for shape selection in the attended location.

Growing up blind does not change the neural bases of theory of mind.

An interesting piece of work from Bedny et al.

Humans reason about the mental states of others; this capacity is called Theory of Mind (ToM). In typically developing adults, ToM is supported by a consistent group of brain regions: the bilateral temporoparietal junction (TPJ), medial prefrontal cortex (MPFC), precuneus (PC), and anterior temporal sulci (aSTS). How experience and intrinsic biological factors interact to produce this adult functional profile is not known. In the current study we investigate the role of visual experience in the development of the ToM network by studying congenitally blind adults. In experiment 1, participants listened to stories and answered true/false questions about them. The stories were either about mental or physical representations of reality (e.g., photographs). In experiment 2, participants listened to stories about people's beliefs based on seeing or hearing; people's bodily sensations (e.g., hunger); and control stories without people. Participants judged whether each story had positive or negative valance. We find that ToM brain regions of sighted and congenitally blind adults are similarly localized and functionally specific. In congenitally blind adults, reasoning about mental states leads to activity in bilateral TPJ, MPFC, PC, and aSTS. These brain regions responded more to passages about beliefs than passages about nonbelief representations or passages about bodily sensations. Reasoning about mental states that are based on seeing is furthermore similar in congenitally blind and sighted individuals. Despite their different developmental experience, congenitally blind adults have a typical ToM network. We conclude that the development of neural mechanisms for ToM depends on innate factors and on experiences represented at an abstract level, amodally.

Empathetic accuracy

Zaki et al show that the accuracy of attributions made about the mental state of others track with activity in structures within the human mirror neuron system thought to be involved in shared sensorimotor representations, and also with regions implicated in mental state attribution - the superior temporal sulcus and medial prefrontal cortex.

Gender–science stereotypes predict national sex differences in science and math achievement

From Nosek et al:

About 70% of more than half a million Implicit Association Tests completed by citizens of 34 countries revealed expected implicit stereotypes associating science with males more than with females. We discovered that nation-level implicit stereotypes predicted nation-level sex differences in 8th-grade science and mathematics achievement. Self-reported stereotypes did not provide additional predictive validity of the achievement gap. We suggest that implicit stereotypes and sex differences in science participation and performance are mutually reinforcing, contributing to the persistent gender gap in science engagement.

Boiling the frog.

Krugman is right on, as usual. This material on our inability to admit or perceive slow changes is hardly novel (cf. Ornstein and Erlich's "New World, New Mind" from 1989), and one can only hope that marketing efforts like those of Al Gore will bring this glitch in our thinking abilities into more common awareness.

Quiet music to start the week - a Grieg elegy

Grieg Lyric Pieces Op 38 No 6 - Elegy

Caloric restriction enhances longevity in monkeys

It all over the newspapers, but I thought I would pass on the link to work just published by my colleagues at the University of Wisconsin:

Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.


Figure - Animal appearance in old age. (A and B) Photographs of a typical control animal at 27.6 years of age (about the average life span). (C and D) Photographs of an age-matched animal on caloric restriction.

Face perception - the "Thacher Effect" in monkeys

Our talent for recognizing differences in faces relies on how facial features are configured. But, if the image of a face is flipped, alterations as drastic as inverted mouths and eyes aren't as noticeable — a phenomenon known as the Thatcher effect. Adachi et al. have monitored the length of time rhesus monkeys (Macaca mulatta) look at pictures of monkey faces. Over time, the animals become less interested in all images, but they spend significantly more time looking at the strange, upright altered (Thatcherized) photos than they do looking at the same images upside down. This suggests that perceptual mechanisms for individual recognition have been conserved through primate cognitive evolution.

Doing exactly what you don't want to do.

Dan Wegner has generated an interesting review of a phenomenon that we all know too well. (Wegner is another one of my heroes. He wrote "The Illusion of Conscious Will" - a book that I reference extensively in my "I-Illusion" web lecture and podcast). The subject of the review is the "Imp in your mind" that makes you sometimes blurt out exactly what you are trying to suppress. The theory is that to suppress an insult, for example, the brain must first imagine just that; the very presence of that catastrophic insult, which in turn increases the odds that the brain will spit it out.

In slapstick comedy, the worst thing that could happen usually does: The person with a sore toe manages to stub it, sometimes twice. Such errors also arise in daily life, and research traces the tendency to do precisely the worst thing to ironic processes of mental control. These monitoring processes keep us watchful for errors of thought, speech, and action and enable us to avoid the worst thing in most situations, but they also increase the likelihood of such errors when we attempt to exert control under mental load (stress, time pressure, or distraction). Ironic errors in attention and memory occur with identifiable brain activity and prompt recurrent unwanted thoughts; attraction to forbidden desires; expression of objectionable social prejudices; production of movement errors; and rebounds of negative experiences such as anxiety, pain, and depression. Such ironies can be overcome when effective control strategies are deployed and mental load is minimized.

Mate selection: women not more picky than men?

Sarah Arnquist points to some experiments that question the conventional evolutionary psychology picture that women are pickier than men when choosing a mate. They suggest social conditioning is more important than the usual evolutionary argument that because women have a bigger investment in reproduction — they are the ones who have to endure pregnancy, childbirth and breast-feeding — they need to hedge their bets against selecting a dud to be the father.