Psychophysiological arousal at encoding leads to reduced reactivity but enhanced emotional memory following sleep

• Published in: Neurobiology of learning and memory Vol. 114; pp. 155 - 164
• Main Authors: Cunningham, Tony J., Crowell, Charles R., Alger, Sara E., Kensinger, Elizabeth A., Villano, Michael A., Mattingly, Stephen M., Payne, Jessica D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-10-2014; Elsevier BV
• Subjects: Affective reactivity; Anatomy & physiology; Arousal - physiology; Emotional memory; Emotions - physiology; Female; Galvanic Skin Response - physiology; Heart rate; Heart Rate - physiology; Humans; Male; Memory; Memory - physiology; Memory consolidation; Psychopathology; Skin conductance response; Sleep; Sleep - physiology; Memory consolidation; Heart rate; Emotional memory; Affective reactivity; Sleep; Skin conductance response
• ISSN: 1074-7427; 1095-9564
• DOI: 10.1016/j.nlm.2014.06.002

•We explore visceral response to emotional and neutral stimuli across sleep and wake.•We investigate how reactivity at encoding affects later memory for these stimuli.•Increased reactivity at encoding correlates with negative memory, only after sleep.•Sleep reduces reactivity to all stimuli.•Wake affects no change in reactivity to the stimuli.
While sleep’s role in emotional memory processing is gaining increasing support, its effect on emotion regulation remains equivocal. Moreover, little is known about the link between emotional reactivity at the time of encoding and subsequent sleep-based emotional memory consolidation. This study examined whether sleep would potentiate, protect, or depotentiate measures of heart rate and skin conductance in response to scenes containing emotional and neutral objects, and assessed how these measures of reactivity would predict subsequent memory for the objects across delays of sleep and wake. Heart rate deceleration (HRD) and skin conductance response (SCR) data were collected at encoding and recognition. Although HRD and SCR reactivity to objects were depotentiated after a sleep-filled delay, they remained unchanged after a delay containing wakefulness. Moreover, increased arousal responses to negative scenes at encoding as measured by HRD and SCR responses were positively correlated with subsequent memory for the negative objects of scenes, but only in the sleep group. This suggests that larger reactions to negative images at the time of encoding set the stage for the preferential consolidation of these images during a night of sleep. Although arousal responses are often thought to account for emotional enhancement in long-term memory, these findings suggest that both an arousal response at encoding and a subsequent period of sleep are needed to optimize selective emotional memory consolidation.