Picture-name priming in the cerebral hemispheres.

In a lexical decision task, pictures and names of common objects were presented in succession to the left or right visual fields in an investigation of the relationship between visual and verbal representations within and between the hemispheres. On each trial, a picture was projected to the left or right side of the visual field, followed by a string of letters to the same or different side. The letter string could be the name of the object in the picture, an unrelated word, or a nonword. Although a strong priming effect was observed when the name of an object followed its picture, this did not depend on which visual fields had registered the stimuli. Activation of name codes was apparently independent of visual field of presentation of picture and word. This result was consistent with the view that representational systems for pictures and their names are not differentially specialized across the hemispheres. A further finding was that absolute response time to words was shorter when stimuli were divided between the visual fields, even at an SOA of 1000 msec. It is suggested that this result is due to the activation of picture-processing mechanisms within a hemisphere by the first (pictorial) stimulus, which causes a delay in processing the subsequent verbal stimulus in that hemisphere.