The neurobiology of human working memory for threat: A multi-method approach

This project will explore how our ability to remember and think about information immediately after perceiving it is affected by how emotional that information is. Previous research conducted by scientists a Bangor University showed that images associated with threat, e.g., angry faces, are more likely to be remembered over brief intervals than non-threatening images, e.g., faces with a neutral expression. This project will build on those previous studies by exploring how emotional information, including images and sounds that are fear evoking, gain preferential processing by the brain. The study will use brain-imaging techniques to investigate the brain systems that control how emotional information influences short term memory. It will also explore the possibility that specific bio-chemicals in the brain, called neurotransmitters, regulate cognitive responses to emotional information. To do this, the project will study short-term memory for emotional information in patients with Parkinson's disease because they are known to be deficient in a specific neurotransmitter that is highly likely to be important in emotional regulation of short-term memory. Asking the same question but using a different method, other parts of the project will examine how genetic variation in the neurotransmitter systems in healthy human adults can be used to account for variations in short term memory for emotional information. The results of the project will provide insight into how the brain uses motivationally relavent information to control memory and conscious experience.

The proposal addresses emotion effects on visual cognition, using the example of working memory for faces. Emotional expression is crucial to face processing, and it is slightly surprising that its effect in face working memory has not been investigated more. In the first study of this topic we showed an angry benefit in working memory. It will be conceptually important to decide whether this benefit is confined to angry, as opposed to other negative or generally emotional faces, whether it transfers to other types of non-social and social stimuli and to identity memory. In a novel design, we will also explore the effects of emotional WM on selective attention. The differential emotion effects on face working memory will allow for an interpretation in the context of evolutionary biology (e.g., the threat associated with angry faces, or fearful faces signalling imminent danger). However, for a truly comprehensive biology of emotion/cognition interactions we will also need to investigate the neural mechanisms at the systems and molecular level. The analysis of specific neurotransmitter effects, especially of the dopamine system, is the primary aim of a patient study in Parkinson's disease and a genetic study. Parkinson's disease provides a lesion model for the study of dopaminergic effects, and the genetic study will specifically investigate a small number of functional polymorphisms of the dopamine and serotonin systems in order to unravel the functional and molecular neuroanatomy of the emotion benefits. This will ultimately result in a cellular model of memory enhancement through recruitment of emotion-related areas and neurotransmitter systems in the service of working memory. We will thus be able to follow the chain of molecular events from the initial perceptual response to an expressive face down to the match-to-sample response that ends a trial, providing the first instance of such 'biology of cognition'.