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 inves tigation of the relationship between visual and verbal representations within and between the hemispheres. On each trial, a picture was proj ected to the left or right side of the visual field, followed by a str ing 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 nonw ord. Although a strong priming effect was observed when the name of an object followed its picture, this did not depend on which visual fiel ds 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 th e hemispheres. A further finding was that absolute response time to wo rds was shorter when stimuli were divided between the visual fields, e ven at an SOA of 1000 msec. It is suggested that this result is due to the activation of picture-processing mechanisms within a hemisphere b y the first (pictorial) stimulus, which causes a delay in processing t he subsequent verbal stimulus in that hemisphere. (C) 1994 Academic Pr ess, Inc.