Bistability in the perception of motion and stationarity: Effects of temporal asymmetry

Evidence for bistability in the perception of motion and stationarity was obtained for a displaced dotfigure embedded in a background of randomly moving noise dots. In the temporal symmetry condition, the figure was presented for the same duration in its two locations; either figure motion or random motion was perceived, depending on the number of noise dots. In the temporal asymmetry condition, the figure was presented for different durations in its two locations; figure motion, a single, stationary figure in a fixed position, or random noise was perceived, again depending on the number of noise dots. Competition between these percepts was established by an analysis of switching rates and by an experiment demonstrating the presence of hysteresis as noise levels were gradually increased and decreased across the figure-motion and figure-stationarity boundaries. This evidence for bistability in the perception of figure motion and figure stationarity (one or the other, but not both, was perceived for the same stimulus) suggested the presence of strong inhibitory competition between motion- and position-detecting mechanisms.     

Evaluation of an islandwide screening,assessment and treatment program

This article reports on the effectiveness of the Islandwide Screening, Assessment, and Treatment Program of the Child Development Project in Bermuda. From 1982 to 1984, approximately 1100 families with 2-year-old children were screened for children's cognitive and language delay, for behaviour management problems and for other home characteristics that put children at risk for later school failure. Children who failed the screening and subsequent assessment procedures (of whom random samples received treatment) and samples of others who passed screening and assessment were evaluated from 1984 to 1986 at 4 years of age. This article focuses on the results of the cognitive and language programs; the more problematic behaviour management analyses were reported elsewhere (Miller and Scarr, 1988). The screening procedures and assessment measures developed for this project were themselves evaluated and adjusted to maximize efficiency and costeffectiveness. The screening and assessment procedures proved effective in bringing to the attention of the Child Development Project those families and children who need developmental services, and in not overidentifying normal children as potentially delayed in development. Two kinds of treatment services were compared: The Mother-Child Home Program (MCHP), administered by paraprofessional toy demonstrators, and other interventions tailored by professionals to the language and cognitive problems of the child (called ‘tailored programs’). Children who were not extremely delayed or disturbed were randomly assigned either to the MCHP or to a tailored program. Neither intervention program was preferable to the other. Even though improved, the 4-year-olds identified as developmentally delayed at 24 months still lagged behind children who passed all parts of screening and those who failed screening but passed assessment 2 years earlier. The screening and assessment procedures were very effective in the early identification of children with developmental problems, but the treatment programs failed to bring most children to normal levels of cognitive and language functioning.     

Apparent duration of long meaningful events and meaningless intervals

Time estimates of 1 1/2-, 5¼-, and 14 1/2-min intervals were obtained from 12 American graduate students and 12 Indian graduate students by the methods of verbal estimation and cross-modality matching. Material presented during stimulus intervals varied in degree of meaningfulness. Each subject was tested on 4 successive days with basically the same material in order to determine the effects of repetition. The relationship between perceived and physical time was found to follow Stevens’ power law, and confidence limits of exponents obtained in this study include the exponents previously reported for short durations. Neither actual judgments nor exponents were affected by cultural background or by cognitive factors such as memory for material presented in the interval, familiarity, complexity, degree of meaningfulness, and repetition. It had previously been reported that time judgments were dependent on these cognitive factors. In light of the present research, it is necessary to review and replicate those studies which support a cognitive view of time perception.     

Letter versus dot stimuli as tools for “splitting the normal brain with reaction time”

Filbey and Gazzaniga (1969) found simple dot-present or -absent reports averaged 35 ms slower for the left than for the right visual field. Other data suggests that verbal processing efficiency differences between the cerebral hemispheres, rather than transcallosal transfer time alone, must be tapped to obtain half-field differences as large as 35 ms. Three experiments were conducted. The first failed to show any half-field differences in vocal RT for dot detection; the second replicated previous reports of significant right field superiority of vocal RT to letter stimuli for right handers, and also showed a substantially smaller half-field difference for left handers; the third experiment, utilizing the fixation control procedure of the second experiment, again failed to show half-field differences for the dot detection paradigm. Differences between the Filbey and Gazzaniga and present results probably reflect important procedural differences. We conclude that transcallosal transfer time for simple dot information is much smaller than assumed by Filbey and Gazzaniga and that the letter report-time task taps hemispheric asymmetries of verbal processing efficiency.     

Competition and cooperation between groups and between individuals

Groups and individuals were compared in two experiments. In the first, two same-sex individuals or two same-sex dyads played 10 trials of a Prisoner's Dilemma matrix game (PDG) for money. Play between individuals was more cooperative and less competitive than play between groups. In the second experiment subjects played 10 trials of either PDG or mutual-fate-control (MFC) matrices. For the MFC matrix the competitive choice, which reduces the opponent's outcomes, but has no effect on own outcomes, reflects a desire to increase one's relative advantage over the opponent. Although cooperation was greater for MFC, for both PDG and MFC matrices groups were more competitive and less cooperative than individuals. A large component of the groups-individuals effect is attributed to the greater desire of groups to “win” or avoid “losing” to the opponent, regardless of their absolute outcomes.     

The association between play materials and social behavior in a mainstreamed preschool: A naturalistic investigation

Social interaction during play with various types of materials was observed during free play in a DARCEE model mainstreamed preschool classroom. Results indicated that the use of play materials by mildly handicapped and nonhandicapped children was quite similar. Blocks and vehicles and water play materials were associated with handicapped/nonhandicapped interactions. Library, fine motor, and art materials were associated with solitary activity; blocks and vehicles, water play, housekeeping and music with cooperative interaction; and blocks and vehicles with conflict. Adult-child interaction was associated with children not engaged with any play materials. Implications for mainstreamed preschool settings are discussed.     

THE ROLE OF RESPONSE DELAY IN IMPROVING THE DISCRIMINATION PERFORMANCE OF AUTISTIC CHILDREN

This study investigated the influence of a response delay requirement on the discrimination performance of autistic children. In the context of a multiple baseline design with subsequent repeated reversals, two conditions were compared: a no-response-delay condition, where the child was allowed to make the target response immediately after presentation of the discriminative stimulus versus a response-delay condition, where the target response was permitted three seconds following the discriminative stimulus when the therapist would signal the child to respond. The results showed that the response-delay condition produced higher levels of correct responding than the no-response-delay condition. In addition, teachers in the research setting rated the response-delay procedure to be a practical and effective teaching technique that could be implemented in a classroom setting. The results were discussed in relation to the literature on impulsivity, and were interpreted as indicating that the response-delay procedure provides a valuable technique for teaching autistic children.     

Contrapower sexual harassment: The effects of student sex and type of behavior on faculty perceptions

The purpose of this study was to assess the effects of sex of offender and type of behavior on faculty perceptions of contrapower sexual harassment. Probability samples of predominately white male and female faculty at two universities in the Midwest were asked to read and make judgments about an incident that might constitute sexual harassment of a faculty member by an opposite-sex student. The effects of offender/student sex, type of harassing behavior, and subject sex were assessed. Some of the results included, as hypothesized, that when the student offender was male, subjects were more likely to: (1) view the incident as harassment, (2) believe the faculty member would be upset, and (3) see the student as responsible, compared to when the student offender was female. Overall, obscene phone calls and explicit verbal-physical harassment were viewed more negatively than written sexual comments and implicit verbal-physical harassment. Female faculty subjects also viewed the incidents as more negative or problematic on several measures than did male faculty.     

Weapons used by juveniles and adults to kill parents

Youths who kill, particularly those who kill their parents, have been a matter of increasing concern in the United States in recent years. Empirical analyses of homicide and parricide cases, however, have been limited. The FBI Supplementary Homicide Report (SHR) Data Base for the 10-year period 1977–1986 was utilized to investigate which weapons were used by children in the United States to kill male and female parents and stepparents in single victim, single offender situations. Biological parents were analyzed separately from stepparents. Significant differences were found in the weapons used to kill male and female parents, the weapons used by juveniles and adults when killing parents and stepfathers, and the weapons used by both juveniles and adults when killing male as opposed to female victims. The age and gender differences found in relation to weapons used to kill parents were consistent with a physical strength hypothesis. The relationship found between offender age and weapon used strongly suggests that the number of parricides committed by juveniles could be somewhat curtailed if access to firearms, particularly rifles and shotguns, was severely restricted.     

Activity settings as the unit of analysis: A theoretical basis for community intervention and development

Theory, methods, and action develop within context, one of which is the intellectual climate of an era. Community psychology is directly and indirectly interactive with many intellectual currents, such as postmodernism, semiotics, hermeneutics, and dialogism. These ideas are discussed as they impact on community psychology, with an emphasis on the reemergence of meaning as a central condition of psychology and community. Meaning is of key importance to the unifying concept in the transactional theoretical model which is presented. How this model might serve as a conceptual framework for an asset approach to community intervention and development is discussed. Increasingly, it is recognized that the development of theory to guide community research and action is necessary to advance intervention and to realize the potential of community psychology. It is argued that community psychology is positioned by concepts and practice squarely at the point of emerging thought, and can make fuondational contributions to general social science. The next article in this special section illustrates concepts of this model in an early education program and the remaining article illustrates the influence of ecocultural factors.