Investigation to Uncover the Electrophysiological Correlates of the Mediating Cognitive Factors, Responsible for the Immediate Emotional Enhancement of Memory

Abstract

Emotional memories are powerful memories that have markedly different phenomenological characteristics, compared to neutral memories. Emotional memories are adaptive and serve to aid survival of organisms. Evidence suggests that emotional events tend to be remembered with a greater depth of sensory and perceptual detail. The phenomenon around such memories has therefore been coined, emotion-enhanced memory (EEM). Much of the research into EEM has focused on the long-term consolidating affects that emotions can have upon memory; with the modulation hypothesis being the predominant theory in the literature. However, it has been noted in the literature that emotional stimuli can also enhance short-term memories, immediately after test. It is suggested that the immediate EEM is driven by changes in the cognitive attributes of emotional stimuli, which facilitates encoding processes; this is known as the cognitive-mediating account of immediate EEM. This research aims to investigate three of the key cognitive mediating factors, implicated in the behavioural literature; distinctiveness, relatedness and attention. Using electrophysiological recordings and event-related potentials, this work aims to further the behavioural research and develop functional accounts of how these cognitive factors can influence the immediate EEM. The results suggest that distinctiveness plays a significant role in the immediate EEM and a functional two-step model is proposed to outline the mechanisms through which it exerts it influence. This works also suggests overt attentional resources play a key role, as part of distinctiveness processing. The results did however find, contrary to the behavioural literature, relatedness is unable to fully account for the immediate EEM. These results are interpreted as supporting a complimentary model of EEM, which involves both the cognitive-mediating account for the immediate EEM and the modulation hypothesis for long-term EEM. These findings are discussed in terms of the real-world implications that emotional memory research can have.