WORD-FREQUENCY MONITORING IN PARKINSON DISEASE - AN ANALYSIS OF ACCURACY AND PRECISION

The judgment of frequency of occurrence of stimuli appearing in a task is a complicated decision. This decision can be independently analyze d using estimates of subject accuracy (where their estimate resembles the true frequency of the stimuli) and precision (sensitive to respons e bias). In this study, the accuracy and precision of Parkison's disea se (PD) patients estimates of the frequency of occurrence of word stim uli were analyzed. The results indicated that the accuracy estimates o f PD patients were not significantly different from normal controls wh ereas their precision of frequency judgments was impaired. Poorer prec ision scores were associated with fewer categories achieved on the Wis consin Card Sorting Test. Using accuracy and precision estimates shoul d improve the characterization of the cognitive processes required in frequency judgments.