Emotion-induced inhibition in aging and Alzheimer's disease

University Of Southern California, Los Angeles CA

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Abstract

Project Summary/Abstract Emotionally arousing stimuli can affect the perception of other items in the environment. A recent theory suggests that increased arousal enhances the representation of important information at the time of arousal and simultaneously inhibits representation of less important information. Inhibition is a cognitive process that is particularly and reliably impaired in older adults. Will older adults, then, fail to exhibit inhibition typically driven by arousal? The goal of this proposal is to identify the arousal-induced attentional mechanisms that may change with age and Alzheimer?s disease (AD). Aim 1 will investigate if older adults inhibit information after an emotionally arousing distractor in the same way as younger adults. Younger adults demonstrate a pattern known as emotion-induced blindness, whereby participants fail to report a task-relevant target when it appears soon after an emotionally powerful distractor. Due to limited attentional inhibition in older adults, and consistent with recent preliminary results, we predict that older adults will not demonstrate emotion-induced blindness similarly to younger adults. Aim 2 will further probe the aspects of emotion-attention processing that are impacted by age-related changes in attention. Older adults may not inhibit information after arousal, but they may still demonstrate enhanced representations for emotionally powerful stimuli. This goal of this aim is to be able to distinguish inhibition, rather than emotional processing, to be the mechanism involved in the age-related changes in arousal-induced attention. Finally, Aim 3 will explore possible neural mechanisms that drive differences in arousal-attention effects between younger and older adults. The locus coeruleus (LC) has been recently implicated in the prioritization of representations under arousal, and its density has been negatively correlated with cognitive decline in older adults. The LC has also been identified as one of the first areas in the brain to express tau pathology ? a marker of AD. In Aim 3 we will specifically examine if LC density and/or AD symptomology will correlate with the impact of emotionally arousing distractors. Behavioral tasks, pupillometry, electrocardiography, and structural MR imaging will be employed to address the aims, providing a rich set of techniques and data analyses to learn and refine during postdoctoral training. The results of this proposal will help inform the understanding of age-related and AD changes in arousal-induced attentional mechanisms, which has implications for the fields of emotion, attention, aging, and tasks that require attentional inhibition in daily life (e.g., driving).