University of Rochester
The Neural Basis of Cognitive Flexibility
Imagine Times Square in New York City: tall buildings, flashing lights, a swarm of people. This scene represents a potential for sensory overload. Our brain has limited processing resources, meaning it cannot fully process all of the information in our complex environment. Instead, the brain uses a collection of filters to determine which aspects of the environment will receive preferential processing. This collection of filters can either boost the processing of behaviorally important information (e.g., the street corner where you are meeting a friend) or suppress the processing of distracting information (e.g., flashing lights from nearby billboards).
Given the brain’s limited processing resources, our lab investigates how the brain balances competing information. For example, collecting information on a presently important aspect of the environment (e.g., a friend waiting on the opposite street corner), while also remaining prepared for the emergence of another, perhaps even more important aspect of the environment (e.g., an approaching car). In other words, we investigate the neural basis of cognitive flexibility. We are specifically investigating two important components of cognitive flexibility: (1) the coordination of different cognitive functions over time and (2) functional specialization within or between different brain regions.
With regard to the coordination of different cognitive functions over time, findings suggest that the brain alternates between states promoting either focus on (i.e., sampling of) a presently important aspect of the environment or a shift of focus to another potentially important aspect of the environment. These states, promoting either sampling or shifting, alternate about four times per second. The critical cognitive flexibility associated with such alternating brain states might, for example, have helped our ancestors forage for food while continuing to monitor for predators. On the flipside, these alternating brain states might lead to periodically re-occurring windows of increased distractibility, even when it is behaviorally beneficial to maintain focus on the task at hand.
With regard to functional specialization, multiple brain regions contribute to the filtering of environmental information. We are investigating how different brain regions uniquely contribute to this filtering. The brain might balance competing information, in part, by maintaining functionally isolated circuits. That is, different brain regions and neural networks contribute to different aspects of information filtering (e.g., enhancement of behaviorally important information vs. suppression of distracting information). In summary, we hope that our research will provide critical insight into how the brain completes everyday tasks that require both focus and preparedness for the unexpected, such as driving a car. In addition to examining how such flexibility can be beneficial, we will examine how it can lead to problems in our distracting modern environments (e.g., with a laptop open in front of us and a smart phone nearby). Finally, we hope that our research will shed new light on brain disorders associated with limited cognitive flexibility, such as attention-deficit/hyperactivity disorder (ADHD), in which individuals can become fixed in brain states associated with either high distractibility or hyper-focus.