HORROR-EVOKED AROUSAL AND AMYGDALA BIAS OF THE MEDIAL TEMPORAL LOBE

Abstract

The ability to learn and predict threats in our environment has a direct impact onwhat and how we encode our experiences into future recollections. Experience of our daily lives has implications for how we eventually gain long-term memory, adaptive strategies to assess and foresee threats are crucial for survival. Yet, how humans encode threat-related experiences is difficult to study in terms of episodic memory (Clewett & Murty, 2019; Murty et al., 2012). From background literature, a model that focuses on brain-related modulation at encoding which then is found to impact the formation and recollection of episodic experience, our recent work has begun to characterize how threat-related arousal either enhances or disrupts temporal order memory (Cliver et al., 2024; Gregory & Murty, n.d.). In both behavioral (Study 1 and Study 2) and neuroimaging (Study 2) analyses to investigate the relationship between threat-related neural circuitry during encoding of short movie clips to test temporal order memory and temporal distance memory. We measured neural circuitry in the medial temporal lobe (MTL), including the amygdala sub-nuclei areas of the basolateral and the central-medial amygdala, the anterior and posterior hippocampus, and the perirhinal cortex. We present neural univariate signals of these regions of interest (ROIs), and functional connectivity between ROIs (basolateral and central-medial amygdala, anterior and posterior hippocampus, perirhinal cortex) to see successful temporal order memory performance and compression or expansion of temporal distance memory. This work highlights the importance of understanding neural processes of threat-related arousal encoding.