The impact of physiological arousal on negative and neutral episodic memories in young and middle-aged adults.

The relationship between physiological arousal and emotional memory enhancement is well established, but how this relationship changes with age remains unclear, especially in understudied middle-aged adults. The present study investigated the impact of physiological arousal on memory for emotional and neutral information across young adulthood and middle age. In this experiment, healthy young (ages 18-35; n = 55) and middle-aged (ages 36-59; n = 41) adults encoded scenes containing negative or neutral objects superimposed on neutral backgrounds, while their physiological arousal was recorded. During the memory test, participants indicated whether objects and backgrounds were same, similar, or new compared to the images they viewed during encoding. Memory for negative versus neutral objects (negative-neutral objects, or negative memory difference) was assessed. We found that heart rate deceleration (HRD) was associated with enhanced negative memory difference, while skin conductance response (SCR) amplitude was linked to a reduced negative memory difference. We also calculated memory trade-off scores to examine memory for central objects relative to their paired backgrounds, separately for scenes with negative (negative memory trade-off) and neutral central objects (neutral memory trade-off). Steeper HRD was linked to an increased negative memory trade-off, while higher SCR amplitude was associated with a decrease in the neutral trade-off effect. Parasympathetically driven HRD may be a more robust predictor of arousal-related memory enhancement than sympathetically driven SCR, especially in middle-aged adults. These findings highlight the importance of considering early age-related changes in autonomic function when examining changes in memory. (PsycInfo Database Record (c) 2026 APA, all rights reserved).