To be human is to be an organism dynamically embracing frequent change. Consider a blues musician who can intently play into a harmonica and then quickly transition to singing, possibly while playing the guitar throughout. At other times, he may remain completely silent. What is perhaps more impressive than his capacity to engage in this varied assortment of behaviors is his ability to demonstrate the relevant ones at the appropriate times (e.g., in close calibration with his band mates). Flexibility like this applies not just to overt behaviors, but internal processing as well. Consider that we sometimes deliberately attend to salient information (e.g., watching for cars or bicycles while crossing the street), while at other times we tune out virtually all environmental distractions unrelated to our task – witness the entrancement of video game players who are immune to interference by anything outside of the TV screen.
How do we claim such flexible control of behavior, and what neural and cognitive factors give rise to it? This broad question continually inspires and guides our lab’s work, which is best characterized as the study of cognitive control. Cognitive control can be thought of as a mechanism that selects behavioral strategies (or “task sets”), updates such strategies, and modulates the degree to which these strategies are automatic (i.e., stimulus-driven) or controlled (i.e., effortfully implemented to override reflexive behavior). Research in this domain cuts across the scientific disciplines of attention, decision making, memory, perception, and learning.
My lab’s research on cognitive control has aimed to shed light on the following questions: 1) How do we focus on behaviorally relevant stimuli and ignore irrelevant stimuli? 2) Why do we “choose” to resist irrelevant stimuli in some situations, but not in others? 3) Does our ability to update task sets fluctuate over time, and if so, why? 4) Does our ability to maintain a single task set fluctuate over time, and if so, why? We have approached these questions using a variety of methods, principally behavioral studies and functional MRI.
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