Laterality and field dependence

The purposes of this study were (1) to replicate a right visual-field advantage for a version of the Embedded Figures Test modified for tachistoscopic presentation and (2) to test for a relationship between field independence and performance on modified Embedded Figures Test items presented to the right visual-field. 34 right-handed subjects were presented Embedded Figures Test items to the left, center, and right visual-fields for 150 msec. The Group Embedded Figures Test was also given. Results showed a right visual-field advantage on the modified embedded-figures test and (2) a negative relationship between Group Embedded Figures Test performance and right visual-field scores. These findings were discussed in terms of the differences between the two versions of the embedded-figures test, memory for simple figures, specificity of judgment, and sustained versus tachistoscopic perception. A tentative conclusion suggests that a better internal representation of the briefly presented complex figures places field-independent subjects at a disadvantage on the modified version of the test.     

Geophysical variables and behavior: XXIX. Impact of atmospheric conditions on occurrences of individual violence among Canadian penitentiary populations

This project studied the effects of weather variables and size of the population on minor and major violence rates within six prisons in the Kingston, Ontario, Canada area from January, 1980 through December, 1983. While weather variables have been studied in relation to mood changes within the general population, this study was the first to analyze the impact of weather variables on rates of violence within the prison setting using forward inclusion multiple regression. Analysis showed that population size consistently appeared positively correlated with assaults on other inmates among the male medium-security prisoners during the summer months. In the summer months, temperature tended to be positively related to some minor kinds of offenses, but in the winter months the relationship was negative. Humidity, rain, sunshine hours, snow, and snow on the ground were not consistently related to incidences of minor and major violence. Indices of geomagnetic disturbances had statistically significant inverse relationships with attempted suicide/self-inflicted injury rates among the male prisoners during the summer months. Over 12 months, wind was generally negatively correlated with incidences of major and minor violence among the male inmates. For 6-mo. periods, wind was generally positively correlated with violence rates during the winter months and negatively correlated during the summer months among the male inmates. The findings relating weather variables to violence rates in the women's prison were consistently in opposition to those found for male prisoners during the 4-yr. period.     

Effects of a paradoxical intervention on a child's anxiety about sleep- and sports-related performance

A paradoxical instruction was used to treat a 10-yr.-old boy's complaint of crying when unable to sleep and the daytime equivalent of fearing the public display of crying when failing at sports performances. The instruction resolved both the sleep disturbance and the public crying. The results suggest that, like adults, children may experience anxiety about sleep difficulties and that paradoxical intention may have promise for the treatment of some children's insomnia.     

Cognitive styles: illusory phenomena

The relationship between cognitive style and illusion magnitude was examined using the assimilation and contrast Delboeuf distortions. As in previous research, field dependence correlated positively with assimilation; however, a significant negative correlation with contrast was also found, suggesting that, while field dependence may involve the illusory integration of the stimulus field, field independence may involve its equally illusory differentiation.     

Handling time and choice in pigeons

According to optimal foraging theory, animals should prefer food items with the highest ratios of energy intake to handling time. When single items have negligible handling times, one large item should be preferred to a collection of small ones of equivalent total weight. However, when pigeons were offered such a choice on equal concurrent variable-interval schedules in a shuttlebox, they preferred the side offering many small items per reinforcement to that offering one or a few relatively large items. This preference was still evident on concurrent fixed-cumulative-duration schedules in which choosing the alternative with longer handling time substantially lowered the rate of food intake.     

Temporal proximity and reinforcement sensitivity in multiple schedules

Distributions of reinforcers between two components of multiple variable-interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15-s or 60-s component durations. The failure to demonstrate the “short-component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60-s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15-s subinterval of the 60-s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance between components.     

Sequential effects in dimensional contrast

Two experiments examined pigeons' response rates during short trials signaled by stimuli closely spaced along a wavelength continuum. In Experiment 1 separate halves of the continuum were correlated with different reinforcement schedules. In Experiment 2, the middle stimulus was accompanied by a lower probability of reinforcement than were the remaining wavelengths. Both procedures resulted in dimensional contrast “shoulders,” seen as relatively enhanced or depressed response rates in the presence of stimuli between the extreme of the continuum and the border separating the positive and negative stimuli. Sequential analyses addressed possible contributions of the following interactions: (a) local contrast, seen when rate during a given schedule depends on the schedule in the just-preceding trial; (b) modification of local contrast by the similarity of the signaling stimuli (P. Blough, 1983); and (c) schedule-independent rate contrast, seen when rate in a given trial depends on the rate controlled by the stimulus that accompanied the just-preceding trial (Malone & Rowe, 1981). Dimensional contrast functions were similar when isolated according to the schedule, to the similarity of the signaling stimulus, and to the response rate of the just-preceding trial. The interactions noted above do not appear to make important contributions to this effect.