Role of interstimulus and stimulus-hemisphere compatibility in the process of interhemispheric integration.

Normal subjects had to name German compound nouns which were presented tachistoscopically. The compound nouns were displayed either unilaterally to the left or right visual field, or bilaterally with one element to the left and one to the right visual field. A distinction was made between the bilateral conditions as to whether the representation of the elements, printed and/or pictorial, included a high or low interstimulus and a high or low stimulus-hemisphere compatibility. Analysis indicated firstly a superiority of the left hemisphere for the naming of compound nouns in mixed print and pictorial representation. Secondly, the performance in the bilateral conditions was moderated by stimulus-hemisphere compatibility. In the process of interhemispheric integration stimulus-hemisphere compatibility proved more crucial than interstimulus compatibility. Analyses of errors further illustrated hemispheric behaviour.