Decreased frontal, striatal and cerebellar activation in adults with ADHD during an adaptive delay discounting task
Acta Neurobiol. Exp.(Wars), 75, 326-338, 2015
Abstract: An important characteristic of childhood attention-deficit/hyperactivity disorder (ADHD) is a bias towards small immediate
versus larger delayed rewards, but it is not known if this symptom is also a feature of adult ADHD. A delay-discounting task
was administered to participants with adult ADHD and a comparison group in conjunction with functional magnetic
resonance imaging. Participants responded to a series of questions that required judgments between small sums of money
available immediately and larger sums obtained after a temporal delay. Question parameters were adjusted by an adaptive
algorithm designed to converge on each participant’s discounting indifference point, an individual set point at which there
is equal valuation of both choices. In all participants, robust task activation was observed in regions previously identified in
functional imaging studies of delay discounting. However, adults with ADHD showed less task activation in a number of
regions including the dorsolateral prefrontal cortex, superior frontal gyrus, anterior cingulate, caudate nucleus and declive
of the cerebellum. Additionally, the degree to which a participant discounted delayed rewards was inversely related to task
activation in the cerebellum. The results suggest that the bias towards immediate rewards in childhood ADHD may not
persist behaviorally, but instead present in adulthood as alterations in frontostriatal and frontocerebellar networks.
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Bongard's work focuses on understanding the general nature of cognition, regardless of whether it is found in humans, animals or robots. This unique approach focuses on the role that morphology and evolution plays in cognition. Addressing these questions has taken him into the fields of biology, psychology, engineering and computer science.
Danforth is an applied mathematician interested in modeling a variety of physical, biological, and social phenomenon. He has applied principles of chaos theory to improve weather forecasts as a member of the Mathematics and Climate Research Network, and developed a real-time remote sensor of global happiness using messages from Twitter: the Hedonometer. Danforth co-runs the Computational Story Lab with Peter Dodds, and helps run UVM's reading group on complexity.
Laurent studies the interaction of structure and dynamics. His research involves network theory, statistical physics and nonlinear dynamics along with their applications in epidemiology, ecology, biology, and sociology. Recent projects include comparing complex networks of different nature, the coevolution of human behavior and infectious diseases, understanding the role of forest shape in determining stability of tropical forests, as well as the impact of echo chambers in political discussions.
Hines' work broadly focuses on finding ways to make electric energy more reliable, more affordable, with less environmental impact. Particular topics of interest include understanding the mechanisms by which small problems in the power grid become large blackouts, identifying and mitigating the stresses caused by large amounts of electric vehicle charging, and quantifying the impact of high penetrations of wind/solar on electricity systems.
Bagrow's interests include: Complex Networks (community detection, social modeling and human dynamics, statistical phenomena, graph similarity and isomorphism), Statistical Physics (non-equilibrium methods, phase transitions, percolation, interacting particle systems, spin glasses), and Optimization(glassy techniques such as simulated/quantum annealing, (non-gradient) minimization of noisy objective functions).