An investigation into some hemispheric asymmetries of short-term information processing

Charman, David Kenneth (1978) An investigation into some hemispheric asymmetries of short-term information processing. University of Southampton, Doctoral Thesis.

Abstract

The reasons for undertaking research into the hemispheric asymmetries of short-term information processing were riven. The major ways that had been advanced for the purposes of investigating hemispheric asymmetries were reviewed and conclusions as to the most appropriate way for investigating hemispheric asymmetries with !n the confines of this research were made. The literature that had been concerned with short-term information processing and/or hemispheric asymetries was reviewed and proposals for research were made. The proposals stemmed from the conflicting findings and conclusions that were apparent in the literature. The research examined the relationship between hemispheric asymetries and the comparing of two alphanumerals at the levels of 'same and differ' responding and 'physical and name' coding for both parallel and sequential presentations of alphanumerale.On the whole, the evidence supported the position that the mature and strongly right-hand person was not left hemisphere specialised for making relatively simple verbal comparisons nor right hemisphere specialised for making relatively simple visuospatial comparisons. This was contrary to other reports. Evidence for such a position only tentatively emerged with parallel present -I I 9iI IItations. But this evidence was oolipaed and pushed into the background by the far greater effects of 'interference' that occurred. This was strongest with the parallel comparing of two name codes. However, the right hemisphere laboured to a far greater extent than the left hemisphere in doing this. But once the coding became sequential (sequential presentations) there was no significant difference between the hemispheres.Although physical coding always remained quicker than name coding the results demonstrated that as the time interval between the presentational onset of the two stimuli increased the response times given to name coding and physical coding converged. This suggested that it became more difficult to maintain a physical code because of decay, and a transcription of this code to a more stable name code became increasingly apparent.No significant differences were found between making a 'same' or 'differ' response. The form of response chosen, in which the subject only responded positively to one type of stimulus (~go-no go~ method) was thought more appropriate then a positive response to both types of stimulus (~go-go~ method), and may have accounted for the contradictory findings of ~same-differ~ responding found in the literature. There was a transfer of facilitated learning between the experimental sessions and a significant variation in the subjects' responses. Explanations for these findings considered the interval between the experimental sessions. This was discussed. All in all, the normal and intact cerebral hemispheres, under the conditions studied here, showed little preference for 'specializations' unless the stimuli had to be coded quickly as when presented in parallel. Only in this latter condition did the hemispheres show some form of asymmetry of specialisation.

This record has no associated files available for download.

Contributors

Download statistics