Lexical-retrieval and semantic memory in Parkinson's disease: The question of noun and verb dissociation

The dissociation between the processing of verbs and nouns has been debated in light of the Embodied Cognition Theory (EC). The objective of this paper is to verify how action and verb processing deficits of PD patients are modulated by different tasks with different cognitive demands. Action and object lexical-semantic processing was evaluated in patients with Parkinson's Disease (PD) and cognitively healthy controls through three different tasks (verbal fluency, naming and semantic association). Compared to controls, PD patients presented worse performance in naming actions and in the two semantic association tasks (action/object). Action verbal fluency performance was significantly associated with PD severity whereas object semantic association deficits and noun verbal fluency scores were associated to lower scores in measures of global cognitive functioning. Our data suggest that semantic deficits are related to the type of cognitive processing and this is in the line with more flexible EC accounts.