Grammatical decision time and visual hemifield stimulation.

Abstract

An experiment was performed to study grammatical decision time to three-letter Hebrew verbs and nouns presented to the right or to the left visual hemifield. Decision time was measured by the subject's manual response involving the movement of the index finger from the middle one of three electronic contact keys, to the right key to indicate the appearance of a verb, and to the left key to indicate the appearance of a noun. A comparison was also made of two response conditions, right hand responding versus left hand responding. The results indicate a greater number of errors in responding to verbs than to nouns, but no difference in accuracy between right visual field (RVF) stimulation and left visual field (LVF) stimulation. In contrast, the results indicate that grammatical decision time to Hebrew verbs is shorter than to nouns for all conditions of stimulation and response. Decision time to verbs appearing in the right visual field (RVF) is shorter than to verbs appearing in the left visual field (LVF). Consequently, the difference in decision time between verbs and nouns is greater for RVF stimulation than for LVF stimulation. There is no difference in decision time for stimulation of the RVF or LVF by nouns. Responding hand also does not affect grammatical decision time to either verbs or nouns in either RVF or LVF stimulation.