Llamas use social information from conspecifics and humans to solve a spatial detour task

Animal Cognition - Learning by observing others (i.e. social learning) is an important mechanism to reduce the costs of individual learning. Social learning can occur between conspecifics but also...     

Predictive pointing movements and saccades toward a moving target

The authors investigated whether and, if so, how velocity information is used to control predictive manual pointing movements and saccades. Participants (N = 6) intercepted an occluded moving target as if it were still visible. They kept their eyes fixated while the target moved. The target traveled over a fixed distance and changed its velocity on the way. The presentation time of the final velocity was varied. Both the eye and the hand overshot the slow target and undershot the fast target, particularly when the duration of the final velocity was short. Thus, responses were biased in the direction of the target's initial velocity. The error seemed to arise because participants did not take their latency into account when aiming at the target. Instead, they strategically aimed farther ahead when the target was fast. Amplitude was also more related to the position of velocity change than to final velocity duration. Both findings suggest that target velocity is not extrapolated but that individuals add an increment to the position of velocity change.     

An islet of social ability in Asperger Syndrome: judging social attributes from faces

We asked adults with Asperger Syndrome to judge pictorial stimuli in terms of certain social stereotypes to evaluate to what extent they have access to this type of social knowledge. Sixteen adults with Asperger Syndrome and 24 controls, matched for age and intelligence, were presented with sets of faces, bodies and objects, which had to be rated on a 7-point scale in terms of trustworthiness, attractiveness, social status, and age, or, in the case of objects, price. Despite impaired performance on two important aspects of social cognition (second-order mentalizing and face recognition) the social judgements of the individuals with Asperger Syndrome were just as competent and consistent as those of their matched controls, with only one exception: there was a trend for them to be less able to judge the attractiveness of faces if they were the same sex. We explain this difference in terms of a weakness in mentalizing, specifically the ability to take a different point of view: While all other stereotypic attributions could be made from an egocentric point of view, judging the attractiveness of faces of one's own sex requires taking the perspective of someone of the opposite sex, a challenge for people with mentalizing problems. We conclude that individuals with Asperger Syndrome show preserved aspects of social knowledge, as revealed in the attribution of stereotypes to pictures of people. These findings suggest that there are dissociable subcomponents to social cognition and that not all of these are compromised in Asperger Syndrome.     

Misleading postevent information and working memory capacity: an individual differences approach to eyewitness memory

The present study examines how individual differences in working memory capacity relate to the effect of misleading postevent information on memory for the original event. Participants were shown a film of a crime event and were then asked to unscramble a narrative that included misinformation regarding some of the film's details. Additionally, the working memory capacity of the participants was measured using the operation‐word span task. Finally, in a free recall test, participants recalled fewer correct details in the misinformation condition compared to the control condition. This effect was negatively correlated with working memory capacity. Copyright © 2002 John Wiley & Sons, Ltd.     

Book reviews

Weiskrantz, L. (1986). Blindsight: A case study and implications. Oxford University Press. Pp. 187. ISBN 0-19-852129-4. £19.50.

Humphreys, G. W. & Riddoch, M. J. (1987). to see but not to see: A case study of visual agnosia. Hove and London: Lawrence Erlbaum Associates Ltd. Pp. 124. ISBN 0-83677-064-9. £12.95.

Downing, J. A. (1988). Advances in psychology: Cognitive psychology and reading in the USSR. Amsterdam: North Holland; Elsevier Science Publishers. Pp. 471. ISBN 0-444-70374-8. $108.00.

John Beech & Ann Colley (Eds.) (1987). Cognitive approaches to reading. Chichester: John Wiley. Pp. xii + 315.

James Wertsch (Ed.) (1985). Culture, communication and cognition: Vygotskian perspectives. Cambridge: Cambridge University Press. Pp. 379. ISBN 0-521-25214-8. £27.50 (Hardback).

Fodor, J. A. (1987). Psychosemantics: The problem of meaning in the philosophy of mind. Cambridge, MA: M.I.T. Press. Pp. xiii, 1-171. ISBN 0-262-06106-6.

Richardson, K. (1988). Understanding Psychology. Milton Keynes: The Open University Press. Pp. 114. ISBN 0-335-09842-8. Paperback £7.95.

Stanovich, Keith E. (Ed.) (1988). Children's reading and the development of phonological awareness. Detroit: Wayne State University Press. Pp. 177. ISBN 0-8143-1909-2. $20.00.

Allport, A., MacKay, D.G., Prinz, W., & Scheerer, E. (Eds.), (1987). Language perception and production: Relationships between listening, speaking, reading, and writing. London: Academic Press. Pp. xiii + 497. ISBN 0-12-052750-2. £32.00

Light, L. L. & Burke, D. M. (eds.) (1988). Language, Memory and Aging. Cambridge: Cambridge University Press. Pp. 280. ISBN-0-521-32942-6. £27.50

Friedman, S.L., Scholnick, E.F., and Cocking, R. R. (1987). Bleuprints for thinking: The role of planing in cognitive development. Cambridge: Cambridge University Press. Pp. xv + 559. ISBN 0-521-25605-4. £40.00.     

On the timescale of stimulus-based action-effect learning

When performing an action, people pick up associations between their actions and the resulting consequences of that action, a phenomenon that has been termed response (R)-effect (E) learning. In the present study, we investigated incidental R-E learning in a forced-choice-that is, a stimulus (S)-based-acquisition mode. Specifically, the study examined at which timescale R-E learning evolves-that is, how many encounters are actually needed to form stable R-E associations. The learning of R-E associations was assessed in a subsequent test phase via effect-based response priming. Experiment 1 tested 4 different numbers of S-R-E repetitions for a 2-2-2 S-R-E mapping. Experiment 2 disentangled the contributions of S-E and R-E associations to the facilitating impact of effect-based response priming by means of a 4-2-4 S-R-E mapping. Experiment 3 investigated whether R-E associations can be picked up even when a given E cannot be unequivocally predicted based on the antecedent S in case of inconsistent S-R-E couplings. Together, the results of the present study clearly show that R-E learning occurs in a stimulus-based action mode and that it evolves very rapidly after only 12 S-R-E repetitions. Moreover, the present findings suggest that at least in this initial phase of learning, complete S-R-E consistency seems to be relevant for R-E learning.     

The solitaire illusion: An illusion of numerosity

A new illusion in which the apparent number of elements of two kinds is determined by their spatial arrangement is described. The illusion is such that one large cluster appears to contain more elements than several small clusters, clustering being determined by Gestalt principles. The illusion was found both in adults and in children of 8 years.     

Tactile sensitivity in Asperger syndrome

People with autism and Asperger syndrome are anecdotally said to be hypersensitive to touch. In two experiments, we measured tactile thresholds and suprathreshold tactile sensitivity in a group of adults with Asperger syndrome. In the first experiment, tactile perceptual thresholds were measured. Two frequencies of vibrotactile stimulation were used: 30 and 200 Hz. The results demonstrated significantly lower tactile perceptual thresholds in the Asperger group at 200 Hz but not at 30 Hz, thus confirming tactile hypersensitivity but only for one class of stimulus. A second experiment investigated whether self-produced movement affected the perception of touch in a group of adults with Asperger syndrome. A suprathreshold tactile stimulus was produced either by the participant (self-produced condition) or by the experimenter (externally produced condition) and participants were asked to rate the perception of the tactile stimulation. The results demonstrated that, while both Asperger and control groups rated self-produced touch as less tickly than external touch, the Asperger group rated both types of tactile stimulus as significantly more tickly and intense than did the control group. This experiment confirms the finding of tactile hypersensitivity, but shows that the perceptual consequences of self-produced touch are attenuated in the normal way in people with Asperger syndrome. An abnormality in this process cannot therefore account for their tactile hypersensitivity.     

Social cognitive neuroscience: where are we heading?

Humans crave the company of others and suffer profoundly if temporarily isolated from society. Much of the brain must have evolved to deal with social communication and we are increasingly learning more about the neurophysiological basis of social cognition. Here, we explore some of the reasons why social cognitive neuroscience is captivating the interest of many researchers. We focus on its future, and what we believe are priority areas for further research.