Poster A81, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Electrophysiological Correlates of Time-Based Prospective Memory in Individuals Across the Lifespan
Erin E. Aisenberg1, Christy C. Chan1, Sarah A. Raskin, Ph.D.1; 1Trinity College
This study investigated the relationship between a clinical measure of time-based prospective memory (PM) and a computerized paradigm (Cona et al., 2012) that examined time-based PM in individuals in different age groups. PM involves the ability to form and realize intentions after a time delay (Einstein & McDaniel, 1990). The Memory for Intentions Screening Test (MIST) was used to clinically assessed both time- and event-related PM, which were compared with the electrophysiological and behavioral data collected as participants completed a computer-based PM task that assessed time-based PM. Older adults performed significantly worse on MIST tasks with a 15-minute time delay, event-based cues, action-based responses, and their total MIST scores were also significantly lower than that of younger adults. On the computerized-PM tasks, older adults performed significantly worse on PM tasks with a 5-minite time delay. ERP data was significantly different between groups only on realized 5-minute PM blocks. In the 275-325 ms post-stimulus time window, older adults had significantly higher amplitudes in left frontal electrodes and significantly reduced amplitudes in right parietal and occipital electrodes indicating their frontal lobes work harder in maintaining the intention. The reduction in the occipital electrode was the only ERP difference that extended into the 550-600 ms post-stimulus time window, a period critical for cue detection. Previously Cona et al. (2012) found a similar pattern in event-based PM, possibly indicating the presence of a separate clock altered the nature of the time-based cue into more of an event-based cue.
Topic Area: EXECUTIVE PROCESSES: Working memory