Neural Patterns Reflect Shared Emotional History.

Emotions shape episodic memories, with emotional context-the affective quality or "hue" of an experience-persisting as part of the event in memory, scaffolding connections between events, and guiding our impressions of the environment. We propose that events encoded in a similar emotional context also exhibit similar patterns of brain activation during retrieval, particularly when such events are negative. To explore this idea, we scanned 33 human participants of all genders using functional magnetic resonance imaging as they completed a two-phase episodic memory task. During encoding, participants viewed trial-unique image pairs: a neutral object alongside a complex picture evoking either a negative or neutral emotional context. Across conditions, images were closely matched on low-level perceptual features. During retrieval, participants were shown the neutral objects again and rated their pleasantness, implicitly recalling their emotional context. To determine whether there is a neural signature that reflects salient emotional contexts, we employed trial-level representational similarity analysis, focusing on three brain areas previously linked to emotional memory, appraisal, and/or affective schemas: ventral visual stream (VVS), hippocampus, and ventromedial prefrontal cortex (vmPFC). Our results demonstrate strong converging evidence of emotional context coding in the VVS, reflecting a shared signature of negative emotional context across retrieval and reinstatement of encoding activation patterns, particularly for negative events. Meanwhile, the hippocampus and vmPFC played a more nuanced role. These findings reveal that content with a shared emotional context evokes brain activity patterns reflecting the essence of its emotional history, highlighting the brain's flexible capacity to integrate affective content into mnemonic representations.