Investigating Dopamine- and Norepinephrine-Linked Variability in Cognitive Control in Lab and in Life
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A series of experiments investigated the relationship between locus coeruleus-norepinephrine (LC-NE) function and striatal dopamine (DA) tone and the flexibility of stability of cognitive control. Across 4 experiments, participants completed an attention shifting task, in which they had to periodically switch the focus of their attention while avoiding distraction. In 3 of the 4 experiments, participants’ eyes were tracked to collect eye blink rate and pupil size, indices of striatal dopamine and LC-NE function respectively. A second aim of this project was to determine whether DA- and NE-linked variability in cognitive control was predictive of more ecologically valid real-world behaviors. To this end, participants in Experiment 4 also completed an additional lab session, in which they performed an internet search task, designed to be similar to what a student might experience in their everyday life. Participants then completed 2 weeks of follow-up questionnaires to provide a self-report of their daily experience of distractibility and flexibility. We hypothesized that observable indices of flexibility and distractibility during the internet search task would mediate the relationship between attention task performance and real-world experiences. Results indicated that EBR is related to attentional flexibility; however the specific shape of the effect was inconsistent across studies, with one showing a linear effect on the ability to update the attentional set, and the other showing a quadratic effect. There were large, consistent main effects of both tonic and phasic pupil measures on attention task performance, with longer latencies, larger phasic responses, and larger baseline pupil sizes all tending to predict slower responding and a higher error rate. There was no clear pattern of pupil effects across conditions, however, and so it is not clear whether pupil-linked changes in task performance are related to specific effects on cognitive control processes, or rather a more general arousing effect on performance. Finally, there were also no clear links suggesting that observable behaviors on our internet search task could be used to bridge between attention task performance and real-world behavior.