Independence of recognition memory and priming effects: a neuropsychological analysis

In order to examine the relation between recognition memory and priming effects, we have tracked the recovery of recognition memory and word completion ability during the hours after individual treatment given as part of a prescribed course of electroconvulsive therapy (ECT). Recognition memory was tested by a three-alternative, forced-choice method. In the word completion test, the initial letters of previously presented words were given as cues, and subjects were asked to complete each cue to form the first word that came to mind. Patients receiving bilateral ECT markedly improved their recognition memory performance 45 min to 9 hr after treatment. Word completion performance was normal at 45 min after treatment and did not change thereafter. Despite exhibiting normal priming effects, patients prescribed bilateral ECT scored at chance levels on recognition tests given 45 min after treatment. These findings support the view that recognition memory and priming are independent memory processes, and they suggest that the processes that support priming make little if any contribution to recognition memory. The results are considered in terms of neuropsychological evidence from amnesic patients for the existence of multiple memory systems.