[Object and action naming in a sentence context in people with Parkinson's disease free of dementia]

Difficulties in action language processing (e.g. verbs) have been described in Parkinson's disease (PD). The embodied cognition approach links this difficulty to degenerative motor process. It has also been suggested that frontostriatal dysfunction could involve executive problems for lexical selection, which is generally more demanding for verbs. From this point of view, difficulties should diminish in a supportive context.

21 non demented people with PD and 16 control subjects were evaluated in an object and action naming task preceded by a sentence context that could be predictive or not of the target word (e.g. 'When the music started the couple began to…' 'dance'). The mobility of actions and the manipulability of objects were also manipulated.

PD patients showed longer response latencies for verbs than the control group. In line with the embodied cognition approach, actions that implied higher mobility were more difficult for the group of people with PD. Moreover, PD patients benefited more from the predictive context for naming objects and actions.

Results suggest that both a disruption at the level of action semantics and a subtle executive dysfunction contribute to lexical access difficulties in people with PD, even in the absence of overt cognitive impairment.