# Valence Effects on Episodic Memory in Young and Old Adults Following Exposure to Emotional Stimuli

## TL;DR

Older adults remember neutral information worse after seeing negative images, with brain activity patterns showing lasting effects of negative emotions and age-related changes in emotional regulation.

## Contribution

This study reveals how negative emotional stimuli disrupt memory in older adults, with distinct neural patterns indicating altered emotion regulation strategies during aging.

## Key findings

- Negative valence impaired retrieval of neutral information in both young and old adults.
- Old adults showed increased hippocampal and frontal gyri activity to compensate for memory declines.
- Positive valence in older adults led to increased neural engagement from exposure to retrieval, indicating emotion regulation changes.

## Abstract

Episodic memory benefits from arousal, with better retrieval linked to arousing to‐be‐remembered information. Arousal's impact on subsequent memory processes, particularly for nonarousing stimuli, remains unclear. Healthy ageing is associated with emotion regulation changes and declines in episodic memory, which may influence how arousal affects memory processes. This functional Magnetic Resonance Imaging (fMRI) study examined the effects of valence on episodic memory in young and old adults, focusing on memory of neutral information following arousal exposure. Neural activity was assessed at three time points: during exposure to arousing and nonarousing images, encoding of neutral videos following image exposure, retrieval of the encoded videos. We hypothesised that valence would induce distinct neural activation across task stages, and exposure to negative stimuli would be associated with worse retrieval. Old adults were expected to show stronger neural responses to positive valence and less disruption from negative valence on memory performance. Behavioural results revealed that only negative valence was associated with impaired retrieval. fMRI results replicated age‐related differences in memory performance, with old adults compensating through increased hippocampal and frontal gyri activity. Negative valence was associated with increased activity in the occipital cortex and precentral gyri, also affecting upcoming encoding with heightened activity in the left insula, precuneus and middle temporal gyrus. In old adults, positive valence prompted increasing neural engagement from initial exposure to retrieval, reflecting changes in emotion regulation strategies. Findings emphasise the enduring impact of negative valence on subsequent cognitive processes and suggest that age‐related changes in emotional regulation influence memory‐related neural processes.

Young and old adults exposed to positive, negative or neutral stimuli showed worse episodic memory following negative valence. Negative stimuli increased neural activity during exposure with lasting effects on subsequent encoding. In old adults, while they failed to neurally differentiate between positive and negative stimuli, positive valence increased its neural impact from initial valence exposure to unrelated retrieval, suggesting a dynamic shift influenced by emotion regulation changes in ageing.