Hemispheric differences in processing visual patterns

The dichotomies verbal/visuospatial, serial/parallel and analytic/holistic are reviewed with respect to differences in hemispheric processing. A number of experimental parameters may be varied in such tasks, and together with certain frequently-occurring weaknesses of experimental design may account for the often discrepant results hitherto reported. The above factors are systematically reviewed, and three further experiments are reported which attempt to fill in the missing designs. Further evidence is given in support of the hypothesis that right-hemisphere superiority is most apparent in processes leading to identity matching. It is quantitative rather than qualitative, and may depend upon operations on the entire gestalt, such as holistic matching, mental rotation, reflection, distortion, etc., rather than, e.g., simultaneous (parallel) processing of discretely analysed or isolated features or elements. On the other hand left-hemisphere involvement in visuospatial processing is thought to reflect analysis of the configuration into its separable components; such processing may be either serial or parallel, and may frequently lead to a judgement different.     

Attribute coding at different levels of processing

Schoolchildren, aged 16 years showed poorer incidental learning for nouns if the orienting task was one of finding rhymes for the items compared to assigning each word to a semantic category. On a recognition task including homophone and synonym foils, rhyming subjects made significantly more phonemic errors, whereas categorizing subjects produced a significantly greater number of semantic confusions. Subjects instructed to construct images for each of the nouns showed a performance pattern similar to the categorizing group. The results are interpreted in terms of Herriot's (1974) view that different levels of processing are associated with the coding of different clusters of stimulus attributes.