“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.     

Recent research trends in testing

Summary: Recent trends in test research as measured by references in Buros' Mental Measurements Yearbooks were investigated. The 24 tests with the greatest number of publications were identified, and growth trends of five major tests (Rorschach, MMPI, TAT, Stanford-Bhet, and SVIB) were shown. The correlation between test publications and test usage was .25. The authors speculated that future research trends might include increasing psychometric attention to behavioral assessment and test modifications for minorities. Based on a survey of psychologists' judgments of test quality, the authors concluded that good psychometric properties do not test leaders make.     

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     

Incidental image memorability

ABSTRACT

Recent studies using intentional memory tasks showed that images differ consistently in memorability. Here, we used a surprise recognition memory test. We asked how incidental encoding would affect the consistency and ranking of the memorability scores. If memorability is truly an intrinsic property of the image, one should not expect large differences between incidental and intentional conditions. On the other hand, participants might process images differently when not anticipating a memory test, yielding different results. The study list of our incidental memory task was identical to our previous, intentional study. Participants were to watch the images of this list carefully as they appeared on the screen one by one (free viewing); supposedly for a study about eye movements. Afterwards, a surprise recognition memory test was administered. Despite the free viewing instructions during the study phase, the resulting incidental image memorability scores still showed high levels of consistency across participants. In addition, the overlap between the incidental and intentional memorability ranking was large. These results provide further support for the idea of memorability as an intrinsic image property and add to its ecological validity, as people rarely memorise images intentionally.     

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.