Event-related potential evidence for memory prioritization modulated by social labels

We investigated whether semantic activation induced by social labels modulates memory prioritization during encoding, as indexed by event-related potentials (ERPs). Specifically, we examined semantic processing and attentional allocation during encoding to identify the stage at which memory enhancement arises.

The experiment consisted of a semantic categorization task during encoding followed by a surprise free-recall test. Participants were assigned to one of two task conditions. In task 1, they judged whether a word belonged to the self category or to non-self categories (friend, irrelevant). In task 2, they judged whether a word belonged to the self or friend category.

We analyzed the N400 and P3b components of ERP data recorded during encoding. Greater N400 attenuation was observed in the self condition in task 1 but not in task 2. Parietal P3b amplitude was larger in the self condition than in the friend and the irrelevant conditions. In the surprise free-recall test, recall performance was highest for self items followed by friend items, and lowest for irrelevant items.

Recall performance demonstrated both a self-prioritization effect and a friend advantage. These results indicate that self-prioritization is more strongly associated with attentional allocation during encoding than with task-driven semantic processing.