Event-related potential repetition effect in alzheimer's patients: Multiple repetition priming with pictures

Abstract

Abstract The most notable symptom in probable Alzheimer's disease (PAD) is a profound deficit on direct or explicit memory tasks. In many cases these same patients show performance similar to normal controls on indirect or implicit memory tasks. During indirect testing, recent studies have shown that many PAD subjects have an intact event-related potential (ERP) repetition effect, which is thought to index indirect memory functioning. the present study was designed to test the effect of multiple repetitions on the ERPs of PAD patients. ERPs were recorded from 8 subjects with PAD, 8 elderly and 16 young healthy controls. Subjects were asked to make speeded but accurate choice responses to infrequently occurring animal pictures and frequently occurring nonanimal pictures. Stimuli were presented in four sets of three blocks of trials. Half of the nonanimal items from the first block of each set were repeated in the subsequent two blocks of trials along with new or foil nonanimal pictures, resulting in three ...