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.     

Self-consciousness,self-report of aggressiveness,and aggression

Private self-consciousness consists of attending to one's thoughts, feelings, and motives. Public self-consciousness consists of attending to oneself as a social object. The effect of dispositional self-consciousness on the accuracy of self-reports was studied in research on aggression. High- and low-private self-conscious subjects rated their own aggressiveness. Several weeks later their aggressive behavior was objectively measured. The correlation between self-report of aggressiveness and aggressive behavior was significantly higher for high-than for low-private self-conscious subjects. The correlation between self-report and behavior was unaffected by public self-consciousness. The implications of these findings for self-consciousness theory and personality dispositions are discussed.     

Self-consciousness and reactance

Two studies examined the effects of dispositional self-consciousness on reactance. In Experiment 1, men who were high in private self-consciousness displayed greater reactance responses to a coercive communication attempt (as reflected by attitude reversal) than did men lower in private self-consciousness. In contrast, the effect of public self-consciousness in this context was to inhibit the expression of reactance. In Experiment 2, women high in private self-consciousness exhibited greater reactance responses to a self-imposed threat to their freedom of choice (as reflected by equivocation over two choice alternatives) than did women lower in private self-consciousness. The effect of public self-consciousness in this context was negligible. These findings replicate and extend a previous self-awareness and reactance finding; they provide additional evidence that manipulated self-awareness and dispositional self-consciousness converge on the same psychological entity; and they provide additional evidence that there are important differences between the dimensions of private and public self-consciousness.     

Poisson signal-detection theory: Link between threshold models and the Gaussian assumption

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

Prophylactic psychiatry

The great contributions of Gantt to the problems of prophylactic psychiatry are pointed out. The author reviews his experiences with a 30-year follow-up of a population of 1800 persons. Over the 30 years, there appeared to be a 50% increase of neuroses, which raises great problems for mental health services. The Berlevåg population was offered optimal psychiatric services. Behavior therapy of neuroses and drug treatment of depression may possibly have lowered the prevalence of mental disorders. Psychophysiologic tests were used in the project. It is hoped that such tests may be utilized for early detection and treatment of mental disorders.     

Focus of attention, chronic expectancy, and responses to a feared stimulus.

An attentional model of fear-based behavior is proposed and a study that tested the model is reported. It was predicted that among subjects with moderate fear of snakes, heightened self-attention during an approach attempt would cause increased awareness of existing anxiety, followed by one of two courses of events: Subjects who believed that they could do the behavior in spite of their fear were expected to redirect their attention to the behavior--goal comparison and exhibit no behavioral deficit. Subjects who doubted their ability to do the behavior were expected to divert their attention from the behavior--goal comparison and to withdraw behaviorally from the approach attempt. The results of the study support this reasoning. Discussion centers on relationships between the proposed model and previous theory.