The perception of continuous curves in dot stimuli

Two categorisation experiments are reported in which the perceptual phenomenon that some simple arrays of discrete dots appear as a continuous curve whereas others are perceived as an angular contour or as consisting of separate groups of dots was investigated. Triplets of dots were presented in the first experiment, and complete or incomplete regular dot polygons (ie dots positioned on the vertices of imaginary regular polygons) in the second. In both experiments the perception of a curve versus an angle was determined mainly by the relative orientations of the dots, ie by the angles between successive virtual lines, whereas the lengths of the virtual lines had relatively little influence. In experiment 2 the number of displayed dots was shown to be a second independent factor for perceiving continuity. These results are in agreement with results from experiments on dipole textures discrimination, and suggest the psychological existence and importance of virtual lines in the visual processing of dot stimuli.     

Stereokinesis with moving visual phantoms

When a flat pattern composed of a solid ellipse with two symmetrical semirings (corresponding to the visible parts of a contour ellipse whose major axis is perpendicular to that of the solid ellipse) is slowly rotated in the frontoparallel plane, a compelling three-dimensional impression occurs. Subjects report seeing an egg-shaped object that is inserted into a circular ring: the two objects move solidly into three-dimensional space and a moving visual phantom is generated so that the ring appears completed by an illusory curved bar in the region closest to the observer during rotation. A number of variations of this illusion are presented. It is shown that stereokinetic phantoms (i) maintain the shape of the inducing elements; (ii) appear only after the stereokinetic transformation has taken place; and (iii) depend on the organization of the three-dimensional percept as a whole. Relations between stereokinetic phantoms and other completion phenomena are presented and discussed.     

Individual differences and measures of aggression in laboratory studies

After inducing hostility toward a confederate by threatening subjects' self-esteem, subjects were then given the opportunity either to deliver shocks (Experiment 1) or to withhold rewards (Experiment 2) from their confederate. Physiological measures were taken prior to the hostility induction, shortly after the induction and, finally, after the opportunity to aggress. Measures of individual differences relating to aggressive behavior were also considered. While the experimental manipulation was the best predictor in the ‘withholding rewards’ condition, measures of dissipation-rumination tendencies and emotional vulnerability were the best predictors in the ‘shock administration’ condition. In both conditions, systolic blood pressure seemed to reflect differences in arousal as a function of the hostility induction procedure, while subjects in the withhold rewards procedure also showed a decrease in systolic pressure after having an opportunity to aggress toward the confederate. It was concluded that not only is the withholding of rewards a more ethically acceptable procedure than shock administration, but it is also more likely to reflect experimental rather than individual difference affects.     

Investigation of a social-interactional model of depression with mildly depressed males and females

Recent research has explored social-interactional factors in the etiology and maintenance of depression. The current investigation further explored the social-interactional model using face-to-face interactions between depressed and nondepressed individuals, as well as the applicability of this model to observed differences in male and female depression. Forty depressed and 40 nondepressed subjects interacted with same or opposite-sex partners. The 20-minute interactions were videotaped and scored with a behavioral coding system. Subjects completed questionnaires concerning perceptions of their partners and the interaction. Results indicated that depressed and non-depressed subjects behaved similarly during the interactions. However, depression was associated with a number of socially unskilled behaviors. Depression in males was related to additional skills deficits not observed for females. While male and female self-report of depression did not differ, males consistently reported greater negative affect. Partner impressions differed based upon sex of partner, and not his or her level of depression. The robustness of the social-interactional model and methodological considerations for future research with this model are discussed.This article is based on the first author's master's thesis conducted under the supervision of the second author who is now at Catholic University. Portions of this research were presented at the 32nd annual meeting of the Southeastern Psychological Association.The authors wish to thank George A. Clum and Thomas H. Ollendick for serving as committee members; Teresa K. Meade for her invaluable help in data collection; and Katie Bechtel, Ruth Townsley, and Mike Cobler for their assistance in scoring and coding data. Thanks also to an anonymous reviewer for helpful comments on an earlier draft of this paper.     

Teaching social skills to emotionally disturbed adolescent inpatients

A social skills training program was evaluated with emotionally disturbed adolescent inpatients. The targeted social skills required an action or reaction within six skill areas. The program was adapted from a commercially available social skills training game that features the use of response specific feedback, self-monitoring, individualized reinforcers, and individualized performance criteria. A peer conducted the baseline and posttraining sessions while the training was conducted by an adult who had no previous interactive history with the subjects. A multiple baseline design across groups demonstrated that the program increased appropriate responding in all skill areas and that these effects generalized during the posttraining peer conducted sessions. A generalization test indicated that the subjects used their newly learned skills with a novel adult outside the training setting. The program appears quite applicable to emotionally disturbed adolescents since it targets skills in a variety of areas and employs standardized procedures to enhance replicability.     

Parental preferences regarding sex education topics for sixth graders

The purpose of this study was to ascertain which sex education topics parents of preadolescents regarded as appropriate for their children. The sample was comprised of 146 respondents randomly selected from a class list of sixth graders in a suburban school district. A mailed, self-administered questionnaire listing 48 possible topics was used to elicit parental response. Pretesting found the questionnaire to be highly reliable (Cronbach's alpha = .95). Overall, parents strongly supported the inclusion of a broad range of sex education topics regardless of parental age, sex, marital status, income, education, or child's sex. Moreover, parents were largely in agreement with the inclusion of sensitive topics in addition to those which were more physiological or behavioral. Catholics more often than Protestants agreed with the inclusion of birth control, abortion, and sterilization even after controlling for income and education. Thus, the findings suggest that parents of sixth graders find a broad sex education program in the school appropriate. To this end, school officials and sex educators should not overlook the needs of preadolescents for sex education solely on the basis of perceived parental opposition.     

Recognizing people seen in events via dynamic "mug shots"

This study examined effects of an event and dynamic mug shots on facial recognition. Witnesses saw either a film of a liquor store holdup staged by six perpetrators, slides of the same targets, or freeze-framed views from the filmed event. Slides of different facial views of targets among 12 foils, or dynamic 180 degrees mug shots of the same men, or multiple static views were administered 24 hr later in yes-no recognition tests. Recognition (d') was poorer for the same men seen in the event than in slides, but better for dynamic than for static mug shots. Nondynamic event characteristics were responsible for poor recognition of people seen in events, whereas dynamic aspects of facial transformations, not multiple views, seemed responsible for the superiority of dynamic mug shots. The implications of these results for issues of ecological validity of traditional face recognition methodology and for static feature models vs. dynamic transformation models of face recognition are discussed.