The role of trace strength in recency and frequency judgements by amnesic and control subjects

Amnesic and control subjects were required to judge the recency and frequency of presentation of complex pictures. The pictures were shown either once or three times 10 min or 24 h before testing. In both groups recency judgements were influenced by frequency of presentation, and frequency judgements by recency of presentation. Because the amnesic patients were unable to discriminate between the effects of repeated presentation and recent presentation, it was concluded that their judgements were determined solely by trace strength. Because controls showed some ability to make this discrimination, it was concluded that their judgements were determined jointly by trace strength and specific information about time and frequency of presentation.