Emotional arousal lingers in time to bind discrete episodes in memory

ABSTRACT

Temporal stability and change in neutral contexts can transform continuous experiences into distinct and memorable events. However, less is known about how shifting emotional states influence these memory processes, despite ample evidence that emotion impacts non-temporal aspects of memory. Here, we examined if emotional stimuli influence temporal memory for recent event sequences. Participants encoded lists of neutral images while listening to auditory tones. At regular intervals within each list, participants heard emotional positive, negative, or neutral sounds, which served as “emotional event boundaries” that divided each sequence into discrete events. Temporal order memory was tested for neutral item pairs that either spanned an emotional sound or were encountered within the same auditory event. Encountering a highly arousing event boundary led to faster response times for items encoded within the next event. Critically, we found that highly arousing sounds had different effects on binding ongoing versus ensuing sequential representations in memory. Specifically, highly arousing sounds were significantly more likely to enhance temporal order memory for ensuing information compared to information that spanned those boundaries, especially for boundaries with negative valence. These findings suggest that within aversive emotional contexts, fluctuations in arousal help shape the temporal organisation of events in memory.

KEYWORDS:

• Episodic memory
• arousal
• emotion
• temporal
• event segmentation

Acknowledgements

The authors thank Zala Reppman and Natalie Plotkin for their assistance with data collection. We also thank Dr. Alexandra Cohen, Dr. Elizabeth Goldfarb, and Camille Gasser for their helpful feedback on earlier versions of this manuscript. Finally, we thank Lila Davachi for financing this project, her invaluable advice, and her helpful input on this project and on earlier versions of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

All experiment/analysis code, data, and stimuli are available on the first author’s OSF page: https://osf.io/dspqv/

Additional information

Funding

This project was funded by federal National Institute of Mental Health [grant number R01 MH074692] to Lila Davachi and by federal NIH [ grant number F32 MH114536] to D.C. and a National Science Foundation Graduate Research Fellowship to M.M.