Retinal projection or size constancy as determinants of the horizontal-vertical illusion?

To compare the influence of the projected retinal size and of the figure size on the perception of the horizontal-vertical illusion, the target size, the viewing distance, and the slant of an illusion figure were varied. In the first experiment the illusion produced by two figures of the same object size but of different retinal size was compared with that of two figures projecting the same retinal size but differing in object size. The illusion diminished when the size of the retinal projection was increased, whereas a change in figure size did not change the illusion. In Exp. II the illusion figure was tilted backwards which reduced the retinal projection of the 'vertical' figure limb. The illusion decreased and became negative as a function of the retinal projection, but this decrease was relatively small compared with the reduction of the retinal image. The results are interpreted as supporting a retinal origin as an explanation of the illusion. Although there is strong evidence for size-constancy scaling in a tilted figure, constancy scaling is considered of minor importance as a determinant of the usual illusion.     

Catamnestic studies in patients with anorexia nervosa in puberty

Catamnestic studies ware performed on 15 subjects (13 female und 2 male) who were treated individually with Leonhard's method for puberal emaciation between 1960 and 1970. 14 of the patients, then children, now have a good physical status with normal weight, are coping well with life and are most cases married. One female patient died at age 31 years; when accepted for treatment 15 years ago there was some doubt regarding the diagnosis of a genuine puberal emaciation, and this doubt grew in the subsequent course of events. No connection could be found between her death and emaciation. We can thus consider that the success of individual treatment with Leonhard's method has been confirmed.     

Anticipatory coarticulation in a patient with apraxia of speech

Articulatory anticipation of vowel gestures was assessed in an apraxic patient, a dysarthric patient, and three normal speakers. The technique of assessment included perceptual identification of gated speech stimuli. The speech material consisted of /getVte/ utterances with the target vowels /i/, /y/, and /u/. In the case of the apraxic patient the gated vowels were identified at a later instant relative to the preceding plosion burst than in the normal speakers. This result was interpreted as reflecting a delayed onset of coarticulatory gestures, in particular lip rounding. The identification rates for the dysarthric's vowels rather reflected the general reduction of this patient's vowel space.     

Development of visually guided hand orientation in reaching

The development of an ability to use vision in adjusting the hand and the fingers to the orientation of an object to be grasped was studied in a group of 15 infants. They were 18 weeks at the first session and were seen at 4-week intervals until 34 weeks old. At each session they were presented with horizontal and vertical rods. The orientation of the hand of the infant when reaching for these rods was measured at each 60-msec interval during the last 540 msec of the approach. It was found that even at the youngest age there were signs of adjustment of the hand to the orientation of the object. However, at that age the adjustments were rather incomplete. During the months that followed there was a rapid improvement in the skill studied. The findings were in accordance with the idea that information about object orientation is accessible to the manual system when infants start reaching for objects but that the system has yet to be tuned and calibrated before functioning adequately.     

Preparation for grasping an object: a developmental study

The development of visually controlled grasping actions was studied in two experiments. An optoelectronic technique (SELSPOT) was used to monitor the opening and closing of the hand during reaching actions by measuring the change in the distance between thumb and index finger. The purpose of Experiment 1 was to establish an adult criterion for the development. It was shown that adults started closing the hand around the target well before touch and that the timing was dependent on the size of the target. The hand started to close earlier when grasping a small rather than a large target. In addition, the degree of hand opening was also less for a small than for a large target. In Experiment 2 it was shown that infants who were 5-6, 9, and 13 months of age also controlled their grasping actions visually and started closing the hand around the target in anticipation of the encounter rather than as a reaction to the encounter. However, the strategy of the two younger age groups was different from that of adults. They started closing the hand closer to the time of contact with the target than did the 13-month-olds, who were comparable to adults in this respect. The timing was not dependent on the size of the target in any of the infant groups. In all age groups, reaching and grasping were most commonly organized in a continuous way; that is, the hand started to close without any interruption in the approach. The opening of the hand was found to be adjusted to target size in the 9- and 13-month-olds but not in the 5-6 month olds.     

Utilization of social sciences in public discourse: Labeling problems

This article reports the main results of an empirical research project on the utilization of social sciences in the field of labor market and educational policy in West Germany since the 1960s. The research interest focused upon utilization of social science knowledge in public discourse paralleling policy decisions. The analysis shows that the social sciences are used extensively for labeling social problems. The use made of social science knowledge can be described as a certain combination of instrumental and conceptual utilization. In the concluding section of the article, the innovation problem of social science utilization is considered. Dr. Matthias Wingens is senior research associate with the Sociological Research Center “Social Problems” at the University of Bremen. His main research interests include the utilization of social science knowledge, the sociology of knowledge, and educational research. Dr. Ansgar Weymann is chair of the Department of Sociology and head of the Sociological Research Center “Social Problems” at the University of Bremen. His main research interests include sociological theory, utilization of social research, research on education, labor market, and employment, and research on socialization and life-course.     

Trading accuracy for speed: gender differences on a Stroop task under mild performance anxiety.

A standard Stroop task was used to examine the effect of performance anxiety on 58 male and 69 female undergraduates. Subjects were approached either by two casually dressed experimenters who did not stress speed or accuracy or by 4 or 5 formally dressed experimenters who stressed quick and accurate performance. Subjects were told the test would assess their "mental acuity"; their responses were visibly tape-recorded. Reaction times did not show differential response by anxiety condition; men and women showed different RTs only in the low-anxiety condition, with women performing significantly more slowly. There were no significant differences for the high-anxiety condition. Analysis of errors showed women were more accurate than men. Men traded accuracy for speed and may have been under equal performance stress in both situations. When performance was not stressed, women were slower and more accurate than men. When performance was stressed, women increased their speed to match that of men while maintaining their greater accuracy.