Left-right differences in tachistoscopic recognition as a function of familiarity and pattern orientation.

Abstract

Left-right differences in tachistoscopi c recognition were studied using firstand fourth-order approximations to English arranged in either horizontal or vertical rows. Letter sequences displayed in the right visual field were identified more accurately than those displayed in the left visual field, regardless of orientation or order of approximation . The difference between orders of approximation was greater for horizontal displays than for vertical displays. The results indicate that the familiarity effect is due, in part, to directional scanning processes and that these scanning processes do not produce a right visual field superiority. It has been well established that tachistoscopically presented verbal material is more accurately identified when it is presented in the right visual field than when it is exposed in the left visual field (Heron, 1957; Mishkin & Forgays, 1952). At least two factors seem to be involved in producing this right visual field superiority. One is cerebral dominance: input to the right visual field has more direct access to the left (speechdominant) hemisphere (Bryden, 1965, 1966; Kimura, 1966). The other is directional scanning: it is easier to scan a row of letters in the right visual field, when one starts by fixating near the beginning of the left-toright scan, than it is to scan a row of letters