Personality profiles of women attending an artificial insemination by donor clinic

The EPQ was administered to 43 women attending an artificial insemination by donor (AID) clinic. The results indicated that relative to age-norms, the women were significantly lower on Psychoticism and Neuroticism, and significantly higher on the Lie scale. There were no differences between those women who did, and those who did not, become pregnant over a 6-month period. On the basis of the personality scores obtained, we would describe women attending AID clinics as calm, controlled individuals who have chosen, in conjunction with their partner, what is a socially-acceptable solution to the problem.     

Optimal allocation of instructional effort to interrelated learning strands

The problem of allocating instructional effort to two interrelated blocks of learning material is studied. In many learning environments, the amount of material that has been mastered in one area of study affects the learning rate in another distinct but related area—for example, the curriculum subjects of mathematics and engineering. A model is developed that describes this phenomenon, and the Pontryagin Maximum Principle of control theory is applied to determine optimal instructional policies based on the model. The nature of this optimal solution is to allocate instructional effort so that the learner follows a maximal average learning rate “turnpike” path until near the end of the study period and then concentrates on only one strand. This strategy, when applied to a more realistic stochastic model, defines a closed-loop feedback controller that determines daily instructional allocation based on the best current estimate of how much the student has learned. This estimate is calculated by a multistage linear filter based on the Kalman filtering technique.     

Constraints on the visual accuracy of drawings produced by young children

Errors made by young children when they are asked to draw a model were investigated in two studies. In the first study, the experimenter asked 5- and 8-year-old children to draw a cup that had a flower decal (transfer) attached to its outside surface, attached to its inside surface or positioned beside it. The 8-year-old children in all conditions produced visually accurate drawings. The 5-year-old children produced visually accurate drawings when the flower decal was positioned beside the cup and when the flower decal was attached to the inside surface of the cup but not when the flower decal was attached to the cup's outside surface. In the second study, 5- and 8-year-old children were asked to draw a cup that had either an intact or a broken handle. The handle area of the cup was either in view or not in view. The 5- and 8-year-old children performed comparably in this experiment. The children had difficulty producing accurate copies of the model only when the cup had a handle and the handle was not in view. Taken together, these studies indicate that 5-year-old children are more likely to produce visually accurate drawings than has previously been supposed. Difficulty in producing accurate drawings occurred when drawing rules and drawing conventions interfered with the task.     

Enhancement of perceptual sensitivity as the result of selectively attending to spatial locations

The present experiment employed a visual signal-detection task within a cost-benefit (inhibition-facilitation) paradigm to examine the effects of selective attention on perceptual sensitivity. A central cue directed the subjects’ attention to either a right or a left spatial location where a detection task was performed. The cue was either a high/low or neutral-validity indicator of the position in which an event was likely to occur. A rating-scale response scheme in conjunction with the subjects’ target signal locational judgments allowed for the construction of ROC curves for each condition. Significant benefits were found for all subjects, supporting the hypothesis that selective attention can enhance perceptual sensitivity. Deallocation of attention resulted in an inhibition of sensitivity in unattended spatial locations. Subjects were consistently most sensitive in the right spatial location. There were no significant differences in overall response bias among the three conditions or in spatial locations. The results support theories of attention, such as “perceptual tuning, ” that suggest very early selective control.     

The effects of physostigmine during the acquisition of avoidance behaviour as a function of the intersession interval

Rats were trained and tested on an avoidance task in a shuttle box. The change in the performance of the control rats over two sessions was found to be a U-shaped function of the interval between the sessions. The change in performance of rats injected with physostigmine prior to the second session was also found to be a U-shaped function of the intersession interval, although the drug was shown to impair avoidance behaviour. These results are consistent with those of Hamburg (1967) and of Biederman (1970), and support the general contention that cholinergic mechanisms in the brain are involved in the control of avoidance and escape behaviour in the rat. They do not, however, necessarily support the hypothesis advanced by Deutsch (1969, 1971) to describe a biochemical basis of learning and memory, especially if it is used to explain the effects of cholinesterase inhibitors on avoidance behaviour in the shurtlebox.     

Some Effects of Reduction of Extra-Classroom Crowding in a School Environment

The effects of reduced enrollment were studied by examining two architecturally identical schools. One school experienced a 43% reduction in enrollment while the other's enrollment remained constant. Reduction in enrollment had a number of positive benefits, including improved attitudes about the school environment and reduced faculty absenteeism. Findings regarding academic performance were less clear.