Aberrant Response Preparation in Parkinson’s Disease.
The basal ganglia circuit plays a fundamental role in the preparation of a response. Individuals with Parkinson’s disease (PD) are considered to have difficulty with two particular aspects of response preparation, namely, the maintenance of cognitive and motor sets and the ability to adequately switch between cognitive and motor sets. The vast majority of substantiating evidence derives from limb motor control, electrophysiological, and neuropsychological research. These investigations have begun to unfold the characteristics and mechanisms of aberrant response processing in PD. The putative deficits of response preparation are likely tied to the impaired processing of internally versus externally generated cues and are discussed in this larger context. Despite the relevance of response “maintenance” and “switching” to the preparatory aspects of speech, little research has been conducted in this area. However, extant investigations on the preparatory aspects of cognitive and motor responses in PD can provide a theoretical basis for rehabilitation strategies. Clinical implications and management suggestions are highlighted. **********