Word search in patients with Parkinson's disease

Abstract A Neisser word-search task and case-series method is employed to show that patients with Parkinson's disease (PD) are slow at word-search from lexical-semantic long-term stores. This slowing is then related to the patients' word-finding impairment in verbal fluency. The results are also compared to those of a patient with bilateral frontal lobe damage, due to Pick's disease. Neisser's word-search task is based on the premise that the time it takes to scan down a (vertical) list of words to identify a target (e.g. ‘any animal’) is a measure of the time taken to select that item in lexical semantic memory. The experimental paradigm is robust. A cognitive neuropsychology approach is necessary for this investigation, as PD double-dissociation data help to eliminate confounding factors in the data interpretation. Attentional problems, for example, are unlikely to account for the significant correlation between verbal fluency and word search stores in PD.