Cortical dynamics of visual motion perception: short-range and long-range apparent motion.

This article describes further evidence for a new neural network theory of biological motion perception. The theory clarifies why parallel streams V1----V2, V1----MT, and V1----V2----MT exist for static form and motion form processing among the areas V1, V2, and MT of visual cortex. The theory suggests that the static form system (Static BCS) generates emergent boundary segmentations whose outputs are insensitive to direction-of-contrast and to direction-of-motion, whereas the motion form system (Motion BCS) generates emergent boundary segmentations whose outputs are insensitive to direction-of-contrast but sensitive to direction-of-motion. The theory is used to explain classical and recent data about short-range and long-range apparent motion percepts that have not yet been explained by alternative models. These data include beta motion, split motion, gamma motion and reverse-contrast gamma motion, delta motion, and visual inertia. Also included are the transition from group motion to element motion in response to a Ternus display as the interstimulus interval (ISI) decreases; group motion in response to a reverse-contrast Ternus display even at short ISIs; speed-up of motion velocity as interflash distance increases or flash duration decreases; dependence of the transition from element motion to group motion on stimulus duration and size, various classical dependencies between flash duration, spatial separation, ISI, and motion threshold known as Korte's laws; dependence of motion strength on stimulus orientation and spatial frequency; short-range and long-range form-color interactions; and binocular interactions of flashes to different eyes.     

The Effects of Decision Outcome Dispersion Upon Organizational Decision Making

The effects of varying decision outcome dispersion on organizational decision making were investigated under individual and group decision making conditions. Thirty-six female and pg]36 male subjects made decisions for organizational decision scenarios in which outcomes affected primarily the decision maker, people other than the decision maker, or a group of which the decision maker was a member. Subjects rated their levels of perceived risk and confidence in their decisions and made decisions within a simulated context of either a small or a large organization. Results indicated that subjects perceived significantly less risk and more confidence in their decisions when outcomes affected primarily themselves rather than others regardless of whether the decisions were made individually or by a group. Males perceived their decisions as significantly more risky than females. Induced organizational size did not significantly influence decision making.

     

Validity of the Threat Index.

The validity of the Threat Index was examined in a study of 42 students and 15 HIV+ clients. When completing the Threat Index, subjects rate the self and death on 30 bipolar adjectives. A count is made of the number of times the same adjective poles are used to describe the self and death. Uses of the same poles are called matches, while uses of different poles are called splits. The Threat Index is based on the assumption that splits indicate threat. Analysis showed that neither splits nor matches were usually threatening and that neither was necessary or sufficient for the experience of threat. These results did not support the validity of the Threat Index.     

Black South Africans and Canadians on neuroticism as a dimension of personality.

This study was done to assess gender and cultural differences on neuroticism as a dimension of personality among both Canadians and Black South Africans. No statistically significant cross-cultural differences were observed. However, statistically significant gender differences emerged among both Canadian and African men and women, with the latter scoring higher on neuroticism than the former.     

Type A behavior, job satisfaction, and stress among black professionals.

Most studies of work-related Type A behavior have been conducted with samples of white men. Using a mail questionnaire to assess Type A behavior, job satisfaction, and daily stress and tension among 250 black men and 233 black women public accountants, the prevalence of Type A behavior and its relationship with satisfaction and stress were highly consistent with those reported for other samples of white men and women.     

Interpretation style and reactance in counselor's social influence.

This study compared two different interpretation styles (tentative and absolute), two levels of subjects' reactance (high and low), and gender on the counselor's social influence, willingness to see the counselor, willingness to help, ability to help, and subjects' anger. No significant main effects or interaction were found for the counselor's social influence, but men in contrast to women perceived the counselor as more willing to help and indicated that they were more willing to see the portrayed counselor. Highly reactant subjects were more willing to see the counselor when absolute interpretations were used; they also thought the counselor was more willing to help when absolute interpretations were used, whereas low reactant subjects thought the counselor was more willing to help when tentative interpretations were used. Mixed results were found for subjects' anger.     

Beliefs about how to reduce anger.

To learn more about people's beliefs about how to reduce anger, 416 college students were asked what they thought would be the effects of various responses to feeling angry. In general, they thought that behaving aggressively would make them feel worse and that distracting themselves and doing something nice for another would make them feel better. However, males, younger subjects, and those who had behaved more aggressively in the past were more likely to feel that behaving aggressively would elevate their mood. These observations are consistent with theories emphasizing the importance of cognitive variables in the experiences of anger and aggression.     

Demographic and intellectual correlates of the Short-term Memory Test.

This study examined the effect of demographic variables and intellectual factors on the Short-term Memory Test. Subjects were 20 patients neurologically diagnosed as brain-damaged. There was only one significant correlation between Verbal IQ and the Short-term Memory Test. Demographic variables of age, education, and sex did not correlate significantly with scores of the Short-term Memory Test.     

Depression, suicide ideation, and aggression among high school students whose parents are divorced and use alcohol at home.

106 high school students from a small rural high school completed the Children of Alcoholics Scale, Zaks and Walters' Aggression Scale, Beck Depression Scale, and a modified version of the Beck Scale of Suicide Ideation. Analyses of variance showed boys were not experiencing suicide ideation any more than girls; suicide ideation was similar across the four grades, but on aggression alcohol-dependent boys scored significantly higher than girls, and in Grade 9 boys' scores were significantly higher than those in Grade 10. The sophomores' scores on alcohol dependency were significantly lower than the freshmen's scores. Boys and children from divorced homes had higher scores on aggression than girls and children from nondivorced homes. Children from homes in which alcohol was used had higher depression scores than children from nonalcoholic homes. Freshman girls and sophomore boys had higher depression scores than senior boys and girls. A Pearson r of 0.28 between scores on alcohol dependency and suicide ideation was significant, but research is needed to understand better the associations of thoughts of suicide and drug-alcohol dependency among these high school students so strategies for prevention and intervention can be focused.     

Gilles de la Tourette syndrome in India: two cases.

Two cases of Gilles de la Tourette syndrome from India are presented. The symptomatology of Tourette syndrome is the same as that documented in western populations which suggests biological factors in the aetiology of the syndrome.