The enactive mind,or from actions to cognition: lessons from autism

Normative-IQ individuals with autism are capable of solving explicit social cognitive problems at a level that is not matched by their ability to meet the demands of everyday social situations. The magnitude of this discrepancy is now being documented through newer techniques such as eye tracking, which allows us to see and measure how individuals with autism search for meaning when presented with naturalistic social scenes. This paper offers an approach to social cognitive development intended to address the above discrepancy, which is considered a key element for any understanding of the pathophysiology of autism. This approach, called the enactive mind (EM), originates from the emerging work on 'embodied cognitive science', a neuroscience framework that views cognition as bodily experiences accrued as a result of an organism's adaptive actions upon salient aspects of the surrounding environment. The EM approach offers a developmental hypothesis of autism in which the process of acquisition of embodied social cognition is derailed early on, as a result of reduced salience of social stimuli and concomitant enactment of socially irrelevant aspects of the environment.     

Comparative cognition: comparing human and monkey memory

Humans store a limited number of items in short-term working memory to perform subsequent operations. A newly described assessment of memory in rhesus monkeys suggests qualitative similarities and quantitative dissimilarities to humans.     

Seeking a spotless mind: extinction, deconsolidation, and erasure of fear memory

Learning to contend with threats in the environment is essential to survival, but dysregulation of memories for traumatic events can lead to disabling psychopathology. Recent years have witnessed an impressive growth in our understanding of the neural systems and synaptic mechanisms underlying emotional memory formation. As a consequence, interest has emerged in developing strategies for suppressing, if not eliminating, fear memories. Here, I review recent work employing sophisticated behavioral, pharmacological, and molecular tools to target fear memories, placing these memories firmly behind the crosshairs of neurobiologically informed interventions.     

Programming paradigms and mind metaphors: convergence and cross-fertilization in the study of cognition

This paper describes a notable convergence between biological organization and programming language abstractions. Our aim is to explore possibilities of cross-fertilization, at both conceptual and empirical levels, towards the understanding of what cognition and cognitive systems might be.     

Animal learning and memory: an integration of cognition and ecology

A wonderfully lucid framework for the ways to understand animal behaviour is that represented by the four ‘whys’ proposed by Tinbergen (1963). For much of the past three decades, however, these four avenues have been pursued more or less in parallel. Functional questions, for example, have been addressed by behavioural ecologists, mechanistic questions by psychologists and ethologists, ontogenetic questions by developmental biologists and neuroscientists and phylogenetic questions by evolutionary biologists. More recently, the value of integration between these differing views has become apparent. In this brief review, we concentrate especially on current attempts to integrate mechanistic and functional approaches.

Most of our understanding of learning and memory in animals comes from the psychological literature, which tends to use only rats or pigeons, and more occasionally primates, as subjects. The underlying psychological assumption is of general processes that are similar across species and contexts rather than a range of specific abilities. However, this does not seem to be entirely true as several learned behaviours have been described that are specific to particular species or contexts. The first conspicuous exception to the generalist assumption was the demonstration of long delay taste aversion learning in rats (Garcia et al., 1955), in which it was shown that a stimulus need not be temporally contiguous with a response for the animal to make an association between food and illness. Subsequently, a number of other examples, such as imprinting and song learning in birds (e.g., Bolhuis and Honey, 1998; Catchpole and Slater, 1995; Horn, 1998), have been thoroughly researched. Even in these cases, however, it has been typical for only a few species to be studied (domestic chicks provide the ‘model’ imprinting species and canaries and zebra finches the song learning ‘models’). As a result, a great deal is understood about the neural underpinnings and development of the behaviour, but substantially less is understood about interspecific variation and whether variation in behaviour is correlated with variation in neural processing (see review by Tramontin and Brenowitz, 2000 but see ten Cate and Vos, 1999).     

Out of mind, out of sight: language affects perceptual vividness in memory

We examined whether language affects the strength of a visual representation in memory. Participants studied a picture, read a story about the depicted object, and then selected out of two pictures the one whose transparency level most resembled that of the previously presented picture. The stories contained two linguistic manipulations that have been demonstrated to affect concept availability in memory, i.e., object presence and goal-relevance. The results show that described absence of an object caused people to select the most transparent picture more often than described presence of the object. This effect was not moderated by goal-relevance, suggesting that our paradigm tapped into the perceptual quality of representations rather than, for example, their linguistic availability. We discuss the implications of these findings within a framework of grounded cognition.     

Medicine through the artist's eyes: before, during, and after the Holocaust

Pre-Holocaust German art celebrates the doctor as a hero, triumphant over disease and poor hygiene. It emphasizes the ontological conception of disease and the ability of medicine to cure pathology or remove it. Some New Objectivity artists question this conceptualization by pushing it to the extreme of realistic representations. However, the clinical encounter has virtually disappeared from post-Holocaust art. Medicine is depicted in three main ways: as an ambiguous and alien Faustian craft; with a focus on holistic notions of healing, thus avoiding biomedicine altogether; or with a focus on the subjective experience of illness, thus ignoring the interaction between medicine and the diseased person.     

Dyskeratosis congenita: telomerase, telomeres and anticipation

Dyskeratosis congenita (DC) is a rare bone marrow failure syndrome that displays marked clinical and genetic heterogeneity. The identification of dyskeratosis congenita gene 1 (DKC1) mutations in X-linked recessive patients initially suggested that DC is a defective pseudouridylation disorder. The subsequent identification of mutations in the telomerase RNA component (TERC) of autosomal dominant DC patients together with the discovery that both TERC and the DKC1-encoded protein, dyskerin, are closely associated in the telomerase complex have suggested that the pathophysiology of DC predominantly relates to defective telomere maintenance. Recent discoveries have shown that autosomal dominant DC exhibits disease anticipation and that this is associated with progressive telomere shortening owing to the haplo-insufficiency of TERC.     

Ecological frames of mind: the role of cognition in behavioral ecology.

Cognitive psychology is the study of how information, from the senses and from memory, is used in the production of behavior. Investigation of the specifics of behavioral adaptation has already led some behavioral ecologists into the domain of animal cognition. I make several arguments for the benefits and the necessity of a sophisticated assessment by ecologists of the cognitive aspects of behavioral adaptation. First, because cognition typically serves to produce adaptive behavior, cognitive structure and function should reflect ecological demands; studies of cognition in ecological contexts are opportunities to understand adaptation. Furthermore, constraints on cognitive properties may help determine how behavior meets the environment. Studies of spatial memory in food-caching corvids exemplify how cognitive aspects of behavior may both reflect and determine specifics of adaptation. Second, many models in behavioral ecology assume certain cognitive abilities, such as timing or counting. Cognitive theory and methodology should be used to determine whether animals possess these abilities. I have provided examples. Third, consideration of cognitive function can lead to original ideas about the details of behavioral adaptation. Without a thorough integration of cognitive psychology with behavioral ecology, our understanding of the relation between behavior and selective pressures will be compromised.     

Estrogen treatment effects on cognition, memory and mood in male-to-female transsexuals

Gonadal hormones, particularly estrogens, have been suggested to influence memory and cognitive tasks that show sex differences. Previously, we reported that male-to-female (M-F) transsexuals undergoing estrogen treatment for sex re-assignment scored higher on verbal Paired Associate Learning (PAL) than a transsexual control group awaiting estrogen treatment. The present study used a more robust design to examine further associations between estrogen and cognition. We assessed additional aspects of memory, including visual, spatial, object and location memory, other cognitive abilities that show reliable sex differences, including verbal and visual-spatial abilities, and mood variables that could mediate associations between estrogen and cognition. In addition to comparing groups of individuals on and off estrogen, we used two repeated measures designs (AB and BA). The AB group was tested prior to hormone treatment and then again after treatment had begun; the BA group was tested while on estrogen treatment and then again when hormones had been withdrawn prior to surgery. Few changes in memory or cognition were observed, and changes that were observed were not consistent across study designs. The lack of significant effects did not relate to mood changes or to the sexual orientation of participants. These findings suggest that estrogen treatment associated with sex change for M-F transsexuals has little or no influence on sex-typed aspects of cognition or memory.     

The prefrontal cortex: categories,concepts and cognition

The ability to generalize behaviour-guiding principles and concepts from experience is key to intelligent, goal-directed behaviour. It allows us to deal efficiently with a complex world and to adapt readily to novel situations. We review evidence that the prefrontal cortex-the cortical area that reaches its greatest elaboration in primates-plays a central part in acquiring and representing this information. The prefrontal cortex receives highly processed information from all major forebrain systems, and neurophysiological studies suggest that it synthesizes this into representations of learned task contingencies, concepts and task rules. In short, the prefrontal cortex seems to underlie our internal representations of the 'rules of the game'. This may provide the necessary foundation for the complex behaviour of primates, in whom this structure is most elaborate.     

Social cognition in anorexia nervosa: evidence of preserved theory of mind and impaired emotional functioning

Background

The findings of the few studies that have to date investigated the way in which individuals with Anorexia Nervosa (AN) navigate their social environment are somewhat contradictory. We undertook this study to shed new light on the social-cognitive profile of patients with AN, analysing Theory of Mind and emotional functioning. Starting from previous evidence on the role of the amygdala in the neurobiology of AN and in the social cognition, we hypothesise preserved Theory of Mind and impaired emotional functioning in patients with AN.

Methodology

Thirty women diagnosed with AN and thirty-two women matched for education and age were involved in the study. Theory of Mind and emotional functioning were assessed with a set of validated experimental tasks. A measure of perceived social support was also used to test the correlations between this dimension and the social-cognitive profile of AN patients.

Principal Findings

The performance of patients with AN is significantly worse than that of healthy controls on tasks assessing emotional functioning, whereas patients’ performance is comparable to that of healthy controls on the Theory of Mind task. Correlation analyses showed no relationship between scores on any of the social-cognition tasks and either age of onset or duration of illness. A correlation between social support and emotional functioning was found. This latter result seems to suggest a potential role of social support in the treatment and recovery of AN.

Conclusions

The pattern of results followed the experimental hypothesis. They may be useful to help us better understand the social-cognitive profile of patients with AN and to contribute to the development of effective interventions based on the ways in which patients with AN actually perceive their social environment.     

The key mimetic features of hoverflies through avian eyes

Batesian mimicry occurs when a palatable species (the mimic) gains protection from predators by resembling an unpalatable or otherwise protected species (the model). While some mimetic species resemble their models closely, other species ('imperfect mimics') are thought to bear only a crude likeness. In an earlier study, pigeons (Columba livia) were trained to recognize wasp images in one experiment and non-mimetic (NM) fly images in another by rewarding the pigeons for pecking on the respective image types. These pigeons were subsequently presented with different images, including seemingly wasp-like hoverfly species, and the recorded peck rates on these images were used as a measure of the pigeons' perception of the hoverflies' mimetic similarity. To identify a candidate set of morphological features that the pigeons used when assessing this mimetic similarity, we first extracted a range of biometrical measurements from images originally presented to the pigeons. We then repeatedly optimized an empirical model in an attempt to match the recorded pigeon peck rates while using as few biometrical features as input as possible. Our models were able to fit the pigeon peck rates with considerable accuracy even while excluding many input features. Antennal length, a feature commonly used to discriminate between flies and wasps, was regularly retained as an input variable, but overall a different set of biometrical features was important for predicting the peck rates of pigeons rewarded for identifying wasps compared to those rewarded for identifying NM flies. In highlighting the importance of specific biometrical features in promoting mimicry and the irrelevance of others, our optimized models provide an explanation as to why certain species that appear to be poor mimics to humans are judged to be good mimics by birds.     

Effects of ambient odors of lavender and cloves on cognition, memory, affect and mood

The effects of the odors of lavender and cloves on three cognitiveskills—memory, affective reaction to the experiment andmood—of college students are studied in two sessions,separated by 1 week. Essential oils of lavender or cloves werediffused throughout the laboratory, or no odor was presented.In the second session, approximately the same number of subjectsfrom each odor condition of the first session influenced arithmeticreasoning in the first session (3 x 3 factorial design). Lavenderadversely influenced arithmetic reasoning in the first session.At the same time, subjects' affective reactions to the experimentwere more favorable with lavender present, though cloves decreasedwillingness-to-return. In the second session, effects on cognitivefunctioning were not evident, and effects on affect were complex:relative to no-odor controls, groups that had odor in at leastone session expressed negative affect and unwillingness-to-return.Discussion concerned implications for the claim that lavenderis physiologically relaxing, the surprising absence of an effectof an effect of odor change on memory, and possible interactionsof odor and personality factors.     

Aberrations of chick eyes during normal growth and lens induction of myopia

Understanding the control of eye growth may lead to the prevention of nearsightedness (myopia). Chicks develop refractive errors in response to defocusing lenses by changing the rate of eye elongation. Changes in optical image quality and the optical signal in lens compensation are not understood. Monochromatic ocular aberrations were measured in 16 chicks that unilaterally developed myopia in response to unilateral goggles with −15D lenses and in 6 chicks developing naturally. There is no significant difference in higher-order root mean square aberrations (RMSA) between control eyes of the goggled birds and eyes of naturally developing chicks. Higher-order RMSA for a constant pupil size exponentially decreases in the chick eye with age more slowly than defocus. In the presence of a defocusing lens, the exponential decrease begins after day 2. In goggled eyes, asymmetric aberrations initially increase significantly, followed by an exponential decrease. Higher-order RMSA is significantly higher in goggled eyes than in controls. Equivalent blur, a new measure of image quality that accounts for increasing pupil size with age, exponentially decreases with age. In goggled eyes, this decrease also occurs after day 2. The fine optical structure, reflected in higher-order aberrations, may be important in understanding normal development and the development of myopia.