Lexical decision, parafoveal eccentricity and visual hemifield.

Abstract

The effect of the eccentricity of parafoveal stimulation on a lexical decision task was studied using stimuli presented to the two visual hemifield. Five-letter word and nonword stimuli were presented to three parafoveal locations ranging over 1 degree angle of eccentricity. Subjects responded manually. The results of the analyses indicated that the average RT to words was approximately 48 msec. shorter than to nonwords. The average RT to a stimulus presented to the RVF was approximately 11 msec. shorter than to a stimulus presented to the LVF. As parafoveal location became more eccentric, RT to all stimuli increased by approximately 37 msec. per degree of eccentricity. A very significant interaction was found between the visual hemifield stimulated and the direction of response to the type of stimulus presented (word/nonword).