Some reflections on the notion of hypotyposis in Kant

In the Critique of Judgement, Kant, despite his strong condemnation of rhetoric, introduces the figure of hypotyposis at the very moment he sets out to tackle the philosophical problem of presentation as such. This study holds that this choice of the rhetorical term is not fortuitous. Its connotations of vivid illustration, synopsis, and moral grandeur serve Kant in arguing that, on a transcendental level, presentation secures the mind's life, unity, and self-affection. Although of rhetorical origin, hypotyposis is thus shown to link up with a specifically philosophical meaning of the term in the writings of Aristotle.     

Stereo-motion cooperation and the use ofmotion disparity in the visual perception of 3-D structure

When an observer views a moving scene binocularly, both motion parallax and binocular disparity provide depth information. In Experiments lA-1C, we measured sensitivity to surface curvature when these depth cues were available either individually or simultaneously. When the depth cues yielded comparable sensitivity to surface curvature, we found that curvature detection was easier with the cues present simultaneously, rather than individually. For 2 of the 6 subjects, this effect was stronger when the component of frontal translation of the surface was vertical, rather than horizontal. No such anisotropy was found for the 4 other subjects. If a moving object is observed binocularly, the patterns of optic flow are different on the left and right retinae. We have suggested elsewhere (Cornilleau-Pérès & Droulez, in press) that this motion disparity might be used as avisual cue for the perception of a 3-D structure. Our model consisted in deriving binocular disparity from the left and right distributions of vertical velocities, rather than from luminous intensities, as has been done in classical studies on stereoscopic vision. The model led to some predictions concerning the detection of surface curvature from motion disparity in the presence or absence of intensity-based disparity (classically termedbinocular disparity). In a second set of experiments, we attempted to test these predictions, and we failed to validate our theoretical scheme from a physiological point of view.     

Illusory conjunctions and the cerebral hemispheres

Two visual half-field experiments tested Moscovitch’s (1979) proposition that cerebral asymmetry does not concern the earliest perceptual stages but only later processing. Subjects were briefly shown displays that included one (Experiment 1) or two (Experiment 2) types of forms differing in size and which, according to previous evidence, might lead to opposite laterality effects. Laterality effects were assessed for correct detections and for illusory conjunctions, both in terms of raw detection scores and in terms of perceptual discriminability (dr scores). In Experiment 1, displays included either rectangles or triangles. In the first case, the target was a cross; in the second case, it was a Star of David. A hemifield x size interaction was observed both on correct detections and on associated discriminability. Yet, no such interaction was obtained for illusory conjunctions or for associated d’ scores. In Experiment 2, the two types of forms were presented simultaneously, with the small ones either inside or outside the large ones. No laterality effects were observed. Some implications of these data for both hemispheric asymmetry and feature integration issues are discussed. The results suggest that early preattentive processes of feature extraction are not lateralized, whereas some integrative mechanisms, such as Treisman’s (1988) focal attention, may operate differently in the two hemispheres.     

Search behaviour of cats (Felis catus) in an invisible displacement test: cognition and experience

An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.     

Changes in information as a function of a culturally appropriate smoking cessation community intervention for Hispanics

Tested a 7-month, media-based, community intervention among Hispanics in San Francisco designed to change levels of information on the damaging effects of cigarette smoking and on the availability of culturally appropriate cessation services. Three community-wide surveys of Hispanics were conducted with independent random samples, two as baselines (n = 1,660 and 2,053) and one postintervention (n = 1,965). Results showed that changes in the level of awareness of cessation services had taken place after implementation of the intervention. Furthermore, those changes took place primarily among the less acculturated Spanish-speaking Hispanics who were the target of the intervention. The changes in information reported here demonstrate that a culturally appropriate information dissemination campaign that utilizes multiple channels can produce changes in a community's level of information even when the campaign is implemented for a relatively short period.     

Tracks and affordances: The sources of a physical ontology

How is meaning assigned to those terms in a theory which are remote from direct observational instantiation? Models and analogies play a role, but close examination of theories in high energy physics shows that the design of experimental apparatus also influences the interpretation of such terms. Certain apparatus favours certain kinds of effects, and this affects the way mathematical theories are interpreted. In particular track producing apparatus becomes involved with theories in which photonic terms are picked out in the theory. A further conceptual constraint is thus introduced. It is argued that this situation favours the interpretation of dispositional properties as affordances rather than as simple dispositions.     

The role accorded to the public by philosophers of science 1

The role accorded to the public by scientists and philosophers of science has undergone an essential historical change in the last three centuries. Public participation in (witnessing of) scientific experiments was considered an important requirement for 17th century experimenters (e.g. for Boyle or Pascal). The cognitive role played by lay persons was later substantially downgraded; witnessing went out of fashion, while science became more and more esoteric and a matter for experts only. Part of this process was that all scientific disciplines became intensively compartmentalized and in consequence a rather puzzling or even paradoxical situation appeared: that the scientists themselves were and are being reduced epistemically to the status of lay persons, outside of their proper field of expertise (as was pointed out by J. Hardwig). The paper deals with some cognitive aspects of this historical process.     

Attachement,solitude et détresse psychologique chez des jeunes adultes

La présente étude vise à examiner la nature des liens entre les styles d'attachement (sécurisant, anxieux/ambivalent et évitant), la solitude et la détresse psychologique (dépression, anxiété, agressivité et problèmes cognitifs) chez des jeunes adultes. L'échantillon se compose de 407 étudiants de niveau collégial dont l'âge moyen se situe à 18 ans. Les sujets doivent répondre à deux questionnaires d'évaluation du style d'attachement, à l'échelle de solitude UCLA, ainsi qu'à l'index de symptômes psychiatriques. Les résultats laissent voir que les individus ayant un style d'attachement sécurisant rapportent moins de symptômes de dépression et de sentiments de solitude que les sujets des styles anxieux/ambivalent et évitant. De même, ils vivent moins d'anxiété, d'agressivité et de problèmes cognitifs que les individus du style anxieux/ambivalent. Par ailleurs, les individus du style d'attachement anxieux/ambivalent sont plus déprimés, anxieux et agressifs que les individus du style évitant. Par contre, aucune différence significative ne ressort entre les sujets des styles d'attachement anxieux/ambivalent et évitant sur le plan des problèmes cognitifs et de la solitude. Des analyses de régression multiple montrent que l'attachement anxieux/ambivalent et la solitude expliquent un pourcentage significatif de la variance associée à la détresse psychologique. Enfin, il ressort que la solitude joue un rôle modérateur dans la relation unissant l'attachement non sécurisant et les problèmes de nature cognitive, alors qu'elle joue un rôle médiateur dans la relation entre l'attachement sécurisant, la dépression et l'anxiété.