Individual differences in working memory capacity and the regulation of arousal

Previously it has been theorized that differential functioning of the locus coeruleus–norepinephrine (LC–NE) system affects people’s ability to regulate arousal, which has impacts on cognitive abilities. In the present study, we investigated three potential mechanisms by which the LC–NE system can fail to regulate arousal appropriately: hypoarousal, hyperarousal, and dysregulation of arousal. Each of these three could potentially account for why arousal affects cognition. To test the contributions of these three mechanisms, the present study examined individual differences in working memory capacity (WMC) and the regulation of arousal using pupillometry. Participants completed multiple complex span and visual arrays change-detection measures of WMC. An eye-tracker recorded pupil diameter as participants completed the visual arrays tasks. We found rather mixed evidence for the three mechanisms. Arousal dysregulation correlated with lower visual arrays performance and more self-reported attentional lapses. However, arousal regulation did not correlate with complex span performance. There was also some evidence for hypoarousal as an explanatory mechanism, as arousal correlated with attentional lapses. We discuss the implications of the results for theories regarding the role of arousal regulation in cognitive performance and individual differences in cognitive abilities.