Expectancy Violation Drives Memory Boost for Stressful Events

Stressful events are often vividly remembered. Although generally adaptive to survival, this emotional-memory enhancement may contribute to stress-related disorders. We tested here whether the enhanced memory for stressful events is due to the expectancy violation evoked by these events. Ninety-four men and women underwent a stressful or control episode. Critically, to manipulate the degree of expectancy violation, we gave participants either detailed or minimal information about the stressor. Although the subjective and hormonal stress responses were comparable in informed and uninformed participants, prior information about the stressor abolished the memory advantage for core features of the stressful event, tested 7 days later. Using functional near-infrared spectroscopy, we further linked the expectancy violation and memory formation under stress to the inferior temporal cortex. These data are the first to show that detailed information about an upcoming stressor and, by implication, a reduced expectancy violation attenuates the memory for stressful events.

Emotional memory

This chapter presents an overview of current conceptualizations of the emotional enhancement of explicit and implicit memory. It postulates that these processes depend largely on arousal-mediated noradrenergic influences on the amygdala, a key hub in a brain network, conveying information about the (emotional) salience of stimuli and events. Selected genetic polymorphisms known to cause individual differences in neurotransmitter systems mediating emotional memory enhancement are described, as well as how these may be used as tools to investigate effects of neuromodulators and hormones on emotional memory and learning. The conclusion drawn is that studies involving candidate gene approaches should be conducted alongside genome-wide association studies (GWAS) in order to improve understanding of how genetic variations and gene clusters affect emotional memory at a molecular level. Combining earlier findings with novel work obtained from genetic studies will help understand how heritability and life experience mediate and aid generate individual differences in brain and behavior function related to emotional memory.

Attention and Emotion-Enhanced Memory: A Systematic Review and Meta-Analysis of Behavioural and Neuroimaging Evidence

ABSTRACTThe interaction between attention and emotion is posited to influence long-term memory consolidation. We systematically reviewed experiments investigating the influence of attention on emotional memory to determine: (i) the reported effect of attention on memory for emotional stimuli, and (ii) whether there is homogeneity between behavioural and neuroimaging based effects. Over half of the 47 included experiments found a moderate-to-large effect of attention on emotional memory as measured behaviourally. However, eye-tracking research provide mixed support for the role of attention-related processes in facilitating emotional information into long-term memory. Similarly, modulations in sensory-related components at encoding were not predictive of long-term memory formation, whereas later components appear to differentially reflect the allocation of attention to heterogeneous emotional stimuli. This dissociation in neurophysiology is paralleled by the activation of distinct neural networks under full- and divided-attention conditions. We quantified the effects of the behavioural, eye-tracking and neuroimaging findings via meta-analysis to show that the neural substrates of attention-related emotional memory enhancement may be sensitive to specific methodological parameters.