“Smart” mechanisms emerging from cooperation and competition between modules

Summary Three sets of experiments are described. The first set concerns the detection of the 3-D possibility of shaded 2-D block patterns. The data indicate that the human perceptual system is able to do this above chance level, but in a specific and restricted way, which suggests the possibility of a module devoted to it. The second set concerns the determination of the 3-D orientation of coloured 2-D patterns. The data show that the human perceptual system uses physical constraints of colour mixing in doing this. Again, the mechanism seems to have characteristics suggesting modularity. The third set is about the detection of skewed symmetry in dot patterns. Skewed symmetry can be used as a source of information about the slant and tilt of a surface with bilateral symmetry present on it. Therefore, a module for recovering this information might exist.All these empirical data show that Fodor's criteria of modularity can be used to test hypotheses about visual mechanisms recovering 3-D information from 2-D inputs. But this does not imply that the results prove modularity and cannot be interpreted otherwise. As an exercise the same story about these experiments is told with the use of jargon from ecological realism and connectionist approaches. It is concluded that some of the approaches to some perceptual mechanisms are not as divergent as they might seem. The main theme underlying modular, connectionist, and ecological approaches is the avoidance of central intelligence agencies by the incorporation of physical constraints. Within this broad framework different questions can be asked and answers attempted that may depend on personal taste.     

Generative theories in language and music descriptions

The style of a set of Swedish nursery tunes is described in terms of a generative rule system. A generative rule system producing melodically similar versions of an old Swedish folk song is also presented. Examples of melodies generated by these two rule systems are given.Both these rule systems are similar in several respects. Thus, the marking of the hierarchical constituent structure seems to be one of the important principles in composing simple melodies.The rule systems also show a number of similarities with the Chomsky & Halle (1968) generative phonology of English. For instance, the procedures used for deriving a stress contour from a tree diagram are almost identical. Moreover, in sentences as in melodies this stress, or prominence contour is of decisive importance to the generation of the surface structure, such as meter, harmony, and sequences of pitches. It is believed that such parallels between language and music reflect characteristics of man's perceptual and cognitive capacities.     

The logical study of science

The relation between logic and philosophy of science, often taken for granted, is in fact problematic. Although current fashionable criticisms of the usefulness of logic are usually mistaken, there are indeed difficulties which should be taken seriously — having to do, amongst other things, with different scientific mentalities in the two disciplines (section 1). Nevertheless, logic is, or should be, a vital part of the theory of science. To make this clear, the bulk of this paper is devoted to the key notion of a scientific theory in a logical perspective. First, various formal explications of this notion are reviewed (section 2), then their further logical theory is discussed (section 3). In the absence of grand inspiring programs like those of Klein in mathematics or Hilbert in metamathematics, this preparatory ground-work is the best one can do here. The paper ends on a philosophical note, discussing applicability and merits of the formal approach to the study of science (section 4).I would like to thank David Pearce and Veikko Rantala for their helpful comments.     

The variety of consequence,according to Bolzano

Contemporary historians of logic tend to credit Bernard Bolzano with the invention of the semantic notion, of consequence, a full century before Tarski. Nevertheless, Bolzano's work played no significant rôle in the genesis of modern logical semantics. The purpose of this paper is to point out three highly original, and still quite relevant themes in Bolzano's work, being a systematic study of possible types of inference, of consistency, as well as their meta-theory. There are certain analogies with Tarski's concerns here, although the main thrust seems to be different, both philosophically and technically. Thus, if only obliquely, we also provide some additional historical perspective on Tarski's achievement.     

Book reviews

Byrne, R. W. and Whiten, A. (Eds.) (1988). Machiavellian intelligence: Social expertise and the evolution of intellect in monkeys, apes, and humans. Oxford: Clarendon press. Pp. xiv + 413. ISBN 0-19-852175-8, £25.00 (paperback).

Dudai, Y. (1989). The neurobiology of memory. Concepts, findings, trends. Oxford: Oxford University press. pp. xi + 340. ISBN 0-19-854261-5, £40.00 (hardback), ISBN 0-19-854229-1, £18.00 (paperback).

Richards, R. J. (1987). Darwin and the emergence of evolutionary theories of mind and behavior. Chicago & London: University of Chicago Press, Pp. xvii + 700. ISBN 0-226-71199-4. £23.95.

Archer, T. & Nilsson, L. (Eds.) (1989). Aversion, avoidance and anxiety: Perspectives on aversively motivated behavior. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc. Pp. 491. ISBN 0-8058-0132-4. £29.95     

Comment on Björn Sahlberg’s paper

This paper is a comment on Björn Sahlberg’s paper on the function of training analysis in the Swedish psychoanalytic association and discusses some aspects of the candidates’ personal analysis and supervision. The paper further suggests some possible sources for inspiration and perspective on organizational and educational issues, for example taking an interest in the epistemology of professions, in what the concept of ‘reflection-in-action’ could mean in the training situation, or in empirical research about the educational models and the practice of psychoanalysis.     

When preschoolers follow their eyes and older children follow their noses: visuo‐olfactory social affective matching in childhood

Recognition of emotional facial expressions is a crucial skill for adaptive behavior that most often occurs in a multi‐sensory context. Affective matching tasks have been used across development to investigate how people integrate facial information with other senses. Given the relative affective strength of olfaction and its relevance in mediating social information since birth, we assessed olfactory–visual matching abilities in a group of 140 children between the ages of 3 and 11 years old. We presented one of three odor primes (rose, fish and no‐odor, rated as pleasant or unpleasant by individual children) before a facial choice task (happy vs. disgusted face). Children were instructed to select one of two faces. As expected, children of all ages tended to choose happy faces. Children younger than 5 years of age were biased towards choosing the happy face, irrespective of the odor smelled. After age 5, an affective matching strategy guided children's choices. Smelling a pleasant odor predicted the choice of happy faces, whereas smelling the unpleasant or fish odor predicted the choice of disgusted faces. The present study fills a gap in the developmental literature on olfactory‐visual affective strategies that affect decision‐making, and represents an important step towards understanding the underlying developmental processes that shape the typical social mind.     

The role of sparsely distributed representations in familiarity recognition of verbal and olfactory materials

We present the generalized signal detection theory (GSDT), where familiarity is described by a sparse binomial distribution of binary node activity rather than by normal distribution of familiarity. Items are presented in a distributed representation, where each node receives either noise only, or signal and noise. An old response (i.e., a “yes” response) is made if at least one node receives signal plus noise that is larger than the activation threshold, and item variability is determined by the distribution of activated nodes as the threshold is varied. A distinct representation leads to better performance and a lower ratio of new to old item variability, than a more distributed and less distinct representations. Here we apply the GSDT to empirical data on verbal and olfactory memory and suggest that verbal memory relies on a distinct neural item representation, whereas olfactory memory has a fuzzy neural representation leading to poorer memory and inducing a larger ratio of new to old item variability.     

Songs to syntax: the linguistics of birdsong

Unlike our primate cousins, many species of bird share with humans a capacity for vocal learning, a crucial factor in speech acquisition. There are striking behavioural, neural and genetic similarities between auditory-vocal learning in birds and human infants. Recently, the linguistic parallels between birdsong and spoken language have begun to be investigated. Although both birdsong and human language are hierarchically organized according to particular syntactic constraints, birdsong structure is best characterized as 'phonological syntax', resembling aspects of human sound structure. Crucially, birdsong lacks semantics and words. Formal language and linguistic analysis remains essential for the proper characterization of birdsong as a model system for human speech and language, and for the study of the brain and cognition evolution.