Every day, we experience action events in which we must remember whether we have done something or not. Previous evidence have suggested that participants’ memory for performed actions is superior to that for actions that were only heard or read in item memory tasks. Can enactment (i.e., performing actions) also improve associative memory? And how enactment change the contribution of memory processes (i.e., familiarity and recollection) to associative memory? 

In a recent study by Prof. Dr. FU Xiaolan’s team from the Institute of Psychology of the Chinese Academy of Sciences and Prof. Dr. Hubert D. Zimmer from Saarland University (Germany) directly addressed these issues by using Event-related potentials (ERPs) technique.

Forty-eight students participated in this experiment; they were randomly assigned to either the subject-performed task (SPT) or verbal task (VT) group.

During studying, participants in the VT group were asked to try to memorize verb–object pairs; participants in the SPT group were additionally asked to pretend to perform the actions with imaginary objects.

During testing, they discriminated between intact, recombined and new items and made Remember/Know judgments; additionally, their EEGs were recorded.

Behavioral result showed that associative recognition was better following SPT than VT. ERP results (see Figure 1, 2, 3) revealed that early frontal event-related potentials (ERPs) were graded according to the item status following SPT (intact>recombined>new), but no such effects were found after VT.

Similarly, the late parietal ERPs were graded following SPT, whereas these effects were smaller and did not differ between intact and recombined items following VT (intact=recombined>new).

We take this as a correlate of memory retrieval of one’s own performance of the studied action (“I was the actor of the action denoted by the intact phrase or I did this specific movement while performing this action”), and this feature is only available after SPT and is different from the recombined phrases.

Collectively, these findings provide convergent evidence that (a) familiarity can contribute to associative recognition if items were unitized during study, (b) SPT supports unitization, (c) SPT enhances associative recognition and (d) both familiarity and recollection contribute to this improvement.