THE VISUAL SYSTEM'S MEASUREMENT OF INVARIANTS NEED NOT ITSELF BE INVARIANT

Abstract— When two shapes that differ in orientation or size have to be compared or objects have to be recognized from different viewpoints, the response time and error rate art systematically affected by the size of the geometric difference. In this report, we argue that these effects are not necessarily solid evidence for the use of mental transformations and against the use of invariants by the visual system. We report an experiment in which observers were asked to give affine-invariant coordinates of a point located in an affine frame defined by three other points. The angle subtended by the coordinate axes and the ratio of the lengths of their unit vectors systematically affected the measurement errors. This finding demonstrates that the visual system's measurement of invariants need not itself be invariant.     

Philosophy of medicine in the Netherlands

This report explores the relationship between philosophy and medicine in the Netherlands. In Section 1 we outline the ups and downs of medico-philosophical research in our country: pre-war flourishing, post-war decline, and modern renaissance. In Section 2 we review recent Dutch literature in the philosophy of medicine. The topics dealt with include methodology of medical science, alternative medicine, the basic concepts of medicine, anthropological medicine, medicalization, medicine and culture, and health care ethics.     

An information processing system for the psychiatric emergency room

An information processing system for a psychiatric emergency room is described. Several studies are presented that show the utility of the system. In the first study, variables involved in diagnosis are explicated. The second study attempts to determine the characteristics that distinguish recidivists from nonrecidivists at an emergency room. The third study attempts to find patient variables related to success in short-term treatment programs. The final study is aimed at discovering whether there are psychopathological effects related to the use of inhalants. Together, these studies show the potential of a mental health information system for learning more about the nature of mental disorders and their treatment.     

Component analysis of the type A coronary-prone behavior pattern in male and female college students

Two studies investigated the psychological dimensions encompassed by the Rosenman Structured Interview (SI) method of assessing the Type A behavior pattern. In Study 1, female students completed the SI and Jenkins Activity Survey (JAS). Factor analysis of the verbal stylistic and answer content components of the SI yielded a 5-factor solution, with one factor--Clinical Rating--accounting for most nonerror variance in Type A ratings. The remaining factors were derived from answer content and correlated more substantially with JAS Type A ratings than with SI Type A ratings. In Study 2, male and female college students completed the SI and JAS and a battery of questionnaires that tap trait dimensions implied by the conceptual definition of Type A. For both males and females, SI ratings of Type A could almost be completely predicted by scores on the Clinical Rating factor. For both sexes, content dimensions of the SI related to other measures of Type A and to Type A-consistent traits, whereas the Clinical Rating factor was only modestly associated with such traits. Moreover, sex differences were observed in the trait constellations composing SI and JAS definitions of Type A. These results suggest that a discrepancy exists between conceptual and operational definitions of the Type A pattern.     

A case report of pathological rule-governed syllable intrusion

A detailed analysis of a unique speech disturbance, marked by the frequent appearance in the speech stream of a meaningless intrusive syllable, is presented. Following a lengthy thoracic surgery, an American English speaking patient began to speak with non-English prosodic patterns, which evolved to a conspicuous intrusion in his speech of the syllable /sis/. This syllable and its variants were attached to words in a manner which conformed to the regular phonological rules in English (for formation of plural, possessive, and third person singular morphemes). The distribution and frequency of the intrusive syllable are described, and possible explanations for the abnormal occurrence of this particular syllable are discussed.