Recognition thresholds in the central and lateral visual fields following temporal lobectomy.

This study examined recognition thresholds for patients wtih unilateral left or right temporal lobectomy and for normal subjects. Material was projected tachistoscopically and successively to the center, left, and right visual fields. Stimuli were random designs and three-letter words oriented vertically. The recognition thresholds of the left temporal and normal groups were comparable, for both sets of stimuli. In contrast, the right temoral group was impaired in the recognition of words and random designs in the central and lateral fields. Results were seen to reflect the processing of units of visual information, whether in the form of letters or random designs, which at this elementary level relates to the right temporal lobe functioning.