The effects of bilateral ECT on primary memory

Sixteen patients treated with bilateral ECT and sixteen students were tested with single-trial free recall. Testing was carried out at both a fast and a slow rate of presentation, and recall was either immediate or delayed for 30 sec. The primary memory component was estimated with five different methods, and it is concluded that this memory component is essentially unaffected by ECT. The results are discussed in relation to other studies showing that individual differences in memory capacity are primarily related to the secondary memory component. It is argued that the results obtained in studies of memory functions in ECT patients and in patients with chronic amnesic syndromes are similar. The normal primary memory component in ECT patients is not considered conclusive evidence of two storage systems.