Abstract
An ambidextrous agrammatic patient with diffuse cerebral infarction in the right hemisphere, showing notable “telegraphic speech,” was investigated for the production of case-marking particles through two kinds of picture-description tasks. The first task was an ordinary picturedescription, in which most of the patient's responses conformed to the subject-object order, thus suggesting his relatively preserved ability to construct so-called “cannonical word orders.” On the second task, in which the patient described pictures using predetermined “sentence-frames” specifying the constructions of sentences to be produced, he made substantial errors in particles when the sentence-frames were those with non-cannonical noun phrase (NP) orders or those which contained only object NP's. The latter result suggested that the patient would rely on the information of NP order in selecting particles. The patterns of errors in the responses in the two tasks suggested that not only separate particles but also “plausible sequences” of particles which would correspond to cannonical NP orders might be preserved, and that such particle sequences could be erroneously activated through utilizing NP-sequence information. The main disturbance in the patient seemed to consist in selecting precise particles and/or in suppressing plausible but inappropriate particles, while he was able, if not accurately, to select particles relying on NP-sequence and/or semantic cues. From these data, it appeared that the grammatical function of precise selection of particles might be localized in the right hemisphere in the patient, whose language lateralization could be anomalous as suggested by his ambidextrosity.
