ABSTRACT
Word-retrieval deficits are common in patients with Parkinson's disease (PD). The impairment seems to be linked to deficits in word search, rather than to problems with task-switching, or other functions of the supervisory attentional system. Preliminary results on such tasks are described and discussed. Word-search deficits linked to fluency impairments are then reported, followed by presentation of task-switching experiments in which subjects must, for example, produce words alternately from the two categories. Control measures were taken to pinpoint the cognitive locus of the PD fluency deficit. Rapid speaking rate was measured for over-learned sequences, that is, so-called "automatic speech". The finding of a verbal fluency by picture-naming correlation in PD is the first step toward fractionation of the fluency task in the service of PD deficit analysis. The verbal fluency task has largely remained unfractionated in its employment within cognitive neuropsychology.
