The differential effects of cueing on recall in Parkinson's disease and normal subjects

Patients with Parkinson's disease (PD) are known to be impaired in supraspan verbal learning due to reduced availability of internal encoding capacity. PD patients may suffer from poor semantic, source and sequential processing capacity. Thirty-three patients with idiopathic PD and 42 matched normal control subjects (NC) were administered the California Verbal Learning Test under 3 conditions of graded cueing. While the PD patients benefited significantly and progressively from increasingly explicit cueing, the NC group did not since their performance was optimal even without cueing. Results are discussed in relation to frontal executive control of attentional resources and the establishment of encoding strategies.