Introduction

Knowledge, Technology &; Policy -     

Role of visual information in ball catching

The present study is concerned with the perceptual information about the body and space underlying the act of catching a ball. In a series of four experiments, subjects were asked to catch a luminous ball under various visual conditions. In general, catching in a normally illuminated room was contrasted with catching the luminous ball in an otherwise completely dark room. In the third and fourth experiments, intermediate conditions of visual information were included. The results suggest that it is possible to catch a ball with one hand when only the ball is visible, but performance is better when the subject has the benefit of a rich visual environment and two hands. The second experiment indicated that subject performance does improve with practice in the dark, but time spent in the darkened room itself doesn't result in a significant decrement in performance. Results of the third study suggest that vision of one's hand does not aid in the performance of this task whereas the presence of a minimal visual frame appears to aid performance. The final study examined the relation between catching performance and body sway under similar visual conditions. Results of this experiment imply that persons who exhibit relatively little postural sway in full-room lighting performed better at this catching task.     

Relations between psychological stress and EEG correlations

In the present study inquiries have been made about the changes EEG cross-correlation in mental activities is subject to. The EEG recordings were made at rest, in visual and acoustical response, when reading and in the solution of an acoustical differentiation problem. In conjunction with plain reflex processes a decline in the intrahemispherical correlation was observed. During complex-structured psycho-request situations dissimilar changes in the EEG correlation have occurred on the scalp. Between the cerebral regions functionally essential for the solution of the problems, an increase in the bio-electric correlation and between other cerebral areas a decline were registered. The findings in conclusion come to realize that the topographic EEG cross-correlation analysis is appropriate to give an insight into the present situation of cerebral functional organization.     

Possibilities and limits of the diagnosis of specific learning disorders with neurophysiologic methods of study

EEG correlation analyses were conducted with children with and without specific learning weaknesses. Reduced left parietal correlation was found in children with dyslectic problems, and in children with adjustment and concentration problems, reduced bioelectric correlation. The frequent evidence of brain injury criteria suggests a link with general affectations of correlation but not specifically with cerebral correlation affections. It would appear to be appropriate to employ computer-assisted EEG correlation analysis, together with frequency analysis and the examination of evoked potentials in objective neurometric diagnosis where children with learning weaknesses are involved.