The visual perception of rigid motion from constant flow fields

Four experiments investigated observers’ judgments of rigidity for different types of optical motion. The depicted structural deformations were of two types: (1) those with nonparallel image trajectories that are detectable from the first-order spatiotemporal relations between pairs of views; and (2) those with parallel image trajectories that can only be detected from higher order relations among three or more views. Patterns were composed of smooth flow fields in Experiments 1 and 3, and of wire frame figures in Experiments 2 and 4. For both types of display, the nonrigidity detectable from the first-order spatiotemporal structure of the motion sequence was much more salient than the deformation detectable only from the higher order spatiotemporal structure. These results indicate that observers’ judgments of rigidity are based primarily on a two-view analysis, but that some useful information can be obtained under appropriate circumstances from higher order spatiotemporal relations among three or more views.     

The effects of situational performance constraints on intrinsic motivation and satisfaction: The role of perceived competence and self-determination

Situational performance constraints, task interest, and pay contingencies were manipulated in a laboratory study in order to investigate the cognitive mechanisms associated with the previously observed detrimental effects of constraints on affective task reactions. It was hypothesized that feelings of task competence and self-determination would account for both the direct and the interactive effects of constraints on motivation and satisfaction. The results of the study indicated that despite the fact that participants' performance was being constrained and they were aware of these constraints, the mere presence of the constraints alone failed to result in lower levels of satisfaction or motivation on a proofreading task. Post hoc analyses suggested that the constraints, in fact, led to negative affective task reactions when they also reduced participants' feelings of competence and self-determination. Interestingly, participants' generalized locus of control was associated with such effects. Internals tended to maintain stronger feelings of competence and self-determination than externals in the presence of constraints, thereby also maintaining greater motivation and satisfaction.     

Extreme itching treated by a family systems approach

A case study is presented in which a 16-year-old daughter developed extreme itching and scratching behavior that was triggered by the occurrence of manifested parental conflict. The daughter's scratching also served the family function of helping the parents avoid marital conflict. Family treatment consisted of helping the parents manifest, negotiate, and resolve marital conflict issues in front of the daughter so that she could experience the benefits of dealing with a family conflict in a functional way. This approach had helped the daughter decrease her anxiety about conflict situations which, in turn, has resulted in a significant decrease in her itching and scratching behavior. In addition, the parents report an improved marital relationship now that the daughter's itching no longer occurs and no longer interrupts the parents' attempts to negotiate marital conflict issues.1979, Fall     

When is an easy task difficult and vice versa? A reply to lane

Lane has argued that kantowitz and Knight incorrectly predicted an interaction between primary and secondary task difficulty for the variable-allocation model of attention. It is shown that such an interaction is indeed obtained if task-performance difficulty is defined in terms of capacity and only reasonable transformations of data are permitted. This interaction holds for any set of monotonic resource operating characteristics.     

Job attachment,satisfaction, and turnover among public sector employees

This study sought (1) to compare the relative predictive powers of job attachment and job satisfaction with respect to turnover among a sample of public employees; and (2) to examine individual and job-related influences on both attitudes. It was found that attachment was a more effective predictor of turnover than overall satisfaction (or any facet of satisfaction), even when the alternative attitude was partialled out. In addition, it was found that individual employee characteristics were more strongly related to attachment than were job characteristics, while the opposite was found for satisfaction. The findings are discussed in the light of previous evidence, and implications are drawn for research in vocational behavior.     

Effect of listener age and situation on the politeness of children's directives

Twenty-one children between the ages of 46 and 52 years made a speaker doll address other dolls that represented an adult, a peer, and a younger listener in command and request situations. Analyses of the politeness of the elicited directives revealed that the effect of the listener's age was greatest in the command situations,with the adult listener receiving the politest directives, followed by the peer and the younger child, respectively. The listener age effect diminished in the request situations, where the child had to ask a favor of the listener. In these situations, the children were very polite to all three listeners. The results are discussed in terms of status relationships between the speaker and the listener.This article is taken from a doctoral dissertation completed at the University of Wisconsin, Madison, under the direction of D. K. Vetter.