The Role of Frontal Cortex in Primate Metacognition

Duke University, Durham NC

Investigators

Abstract

Award Title: The Role of Frontal Cortex in Primate Metacognition Award Abstract: Rarely do we stop thinking. The mental experience of humans is one of continuity, with thoughts leading to other thoughts. When we reflect on our past decisions and ponder how we may act in the future, we are manipulating our own thought processes, a process termed metacognition. Most research on thought processes at both the psychological and neural levels has focused on single events such as how we remember a picture or decide our next move in a game of chess. Little is understood about serial cognitive events, such as the chain of decisions required to plan several moves ahead in chess. Understanding how individual thought processes influence each other -- venturing beyond cognition to metacognition -- is a challenging but important next step for brain research. Dr. Marc Sommer at Duke University studies metacognition using novel approaches that combine psychological experiments with direct recordings of neurons in the brain. With his Duke colleague, computational neuroscientist Dr. Jeff Beck, he examines not only how decisions are made, but also how they are remembered and controlled. Psychological testing of humans and non-human primates reveal how well they adjust their decision-making when circumstances change, and computer-aided modeling of the data allows for precise comparisons of metacognitive abilities between subjects and species. Neural recordings from the frontal cortex of non-human primates while they control their own decisions sheds light on how the brain is able to link thoughts across time. Specific implications of this work include a better understanding of human cognition and behavior in fast-paced and unpredictable situations that require constant evaluation and planning of decisions. The project will offer hands-on laboratory training opportunities for undergraduates and high school students and will be highlighted in STEM outreach to K12 schools, community lectures, and lay articles on cognitive neuroscience. The research aligns with the public's emerging interest in metacognition as an important factor in education, mental health, and the management of oneself and others. The experimental approach is to use an integrated set of psychophysical and neurophysiological studies in which all data are analyzed and interpreted with computational modeling. The rationale for the project is that humans are adept at metacognitive operations, for example thinking about how to make a later decision, but little is known about the underlying neural mechanisms. Dr. Sommer previously recorded from neurons in the monkey frontal lobe and discovered signals in one area, the supplementary eye field (SEF), that maintained a trace of past decisions. The overall hypothesis of this proposal is that the SEF contributes, as well, to the metacognitive control of future decisions. The first objective is to quantify metacognitive behavior in monkeys as compared with humans. Both species will be tested on a novel rule selection task. Within a trial, subjects select a rule for making a visual decision (metacognitive control), but across trials, subjects bias their rule selection based on past outcomes (metacognitive monitoring). The second objective is to determine whether SEF activity is related to metacognitive control and monitoring. The approach will be to record from neurons in monkey SEF during the rule selection task. The third objective is to test whether the SEF is necessary for metacognitive control and monitoring. The approach will be to reversibly inactivate the monkey SEF during the rule selection task. Dr. Beck will assist with modeling and analysis of the data to ensure all results are statistically sound and clearly interpretable.