Memorization Modulates the Lifespan of Event Files

The present study examined whether memorization influences retrieval of stimulus-response (S-R) representations, or event files. Repeating some but not all features of an event file impairs performance (partial repetition costs). Previous findings show smaller partial repetition costs after long than short intervals between formation and retrieval, suggesting that event file representations decay within a few seconds. Short-term memory processes such as rehearsal or attentional refreshing may mitigate this decay and preserve event files. In this experiment (N = 223), participants performed an S1R1-S2R2 task and were either instructed to memorize S1 identity (memorization group) or received no such instruction (control group). Partial repetition costs were compared between short (500 ms) and long (5,000 ms) intervals between R1 and S2. The memorization group also completed a forced-choice S1-identity memory task after each trial. In both groups, partial repetition costs were smaller after long than short R1-S2 intervals in response times and error rates. Partial repetition costs were also larger in the memorization group than in the control group across both intervals. In error rates, this group difference was modulated by interval length, with larger partial repetition costs following short intervals in the memorization group; a supplementary check showed this pattern was sensitive to a small number of trials, possibly reflecting reduced power (see Discussion). Exploratory analyses showed that better S1 memory performance was associated with slower event file decay. The findings provide evidence that memorization can mitigate event file decay, with implications for the interplay between binding, attention, and short-term memory.