CEREBRAL MECHANISMS FOR SUPPRESSION OF INAPPROPRIATE INFORMATION DURING SENTENCE COMPREHENSION

In two experiments we investigated the extent to which interference fr om centextually inappropriate information was attenuated or suppressed over time in the two cerebral hemispheres during sentence comprehensi on. Subjects viewed centrally presented sentences ending in either a h omophone or a homograph and made speeded judgments as to whether a lat erally presented test word was related to the overall meaning of the s entence. Suppression of contextually inappropriate forms of homophones was found when test words were presented to either hemifield, but sup pression of inappropriate senses of homographs was found only when tes t words were presented to the right visual hemifield. The results from the homograph experiment are consistent with the hypothesis that righ t and left hemisphere semantic selection systems operate in qualitativ ely different ways. The results from the homophone experiment suggest that while the left hemisphere may be more efficient at suppression, b oth hemispheres possess the ability to suppress inappropriate informat ion to some degree. (C) 1996 Academic Press, Inc.