Carl L. Hart, Ph.D.
Dr. Hart is an Assistant Professor of Clinical Neurobiology in the Department of Psychiatry and an adjunct faculty member in the Department of Psychology at Columbia University. He is also a Research Scientist in the Division of Substance Abuse at the New York State Psychiatric Institute. Dr. Hart received his undergraduate degree in psychology at the University of Maryland (1991), and completed his graduate training in experimental psychology and Neurobiology at the University of Wyoming, where he received a M.S. (1994) and a Ph.D. (1996). Dr. Hart’s graduate research was conducted in the laboratory of Dr. Charles Ksir, where he studied dopamine clearance in the nucleus accumbens and locomotor activation following systemic nicotine administration. During the course of Dr. Hart’s graduate education, he earned an NIH Intramural Research Training Award, which allowed him to study metabolism of brain catecholamines following acute and chronic stress in the laboratory of Dr. Irwin J. Kopin. Following graduate school, Dr. Hart participated in postdoctoral research training at the University of California at San Francisco, Yale University, and Columbia University. After completing the Substance Abuse Postdoctoral Training Program at Columbia University with Drs. Marian W. Fischman, Richard W. Foltin, and Herbert D. Kleber, he joined the faculty in the Division on Substance Abuse. Since arriving at Columbia, Dr. Hart’s research has focussed on the evaluation of drug effects on workplace-relevant behaviors and the development and implementation of new executive cognitive tasks that can be used to assess the functioning of drug abusers.

E-Mail: clh42@columbia.edu

Current Research Activities
1. Laboratory model of shift work: Recently, Dr. Hart and colleagues developed a laboratory model of shift work and have begun characterizing drug effects on individuals working irregular schedules. They have shown that that psychomotor performance and mood are disrupted during night shift work; these shift change-related effects are differentially modified by the hypnotic zolpidem administered one hour before bedtime and the stimulant methamphetamine administered one hour after waking. Zolpidem improves subjective reports of sleep quality and, to a lesser extent, performance. Next-day mood, however, appears to be worsened by zolpidem, particularly during the night shift condition. In contrast, methamphetamine attenuates virtually all night shift-related performance impairments. The results from these studies may be of particular significance in occupations that require abrupt changes in work schedules, e.g., health care workers, police officers, and military personnel.

2. Assessment of cognitive functioning during intoxication: A major focus of this research is the development and implementation of new complex cognitive tasks that are sensitive to drug effects. Complex cognitive performance (e.g., shifting of mental sets, inhibiting of prepotent responses, abstraction) during acute marijuana intoxication has received little formal experimental attention. We have begun evaluating the effects of acute marijuana smoking on complex cognitive performance in experienced marijuana smokers. Our data indicate that marijuana has no effect on accuracy on measures of cognitive flexibility, mental calculation, and reasoning, but it significantly increases the number of premature responses and the time participants require to complete many cognitive tasks. Findings from this research suggest that the consistent slowing of cognitive performance during intoxication may have significant behavioral effects under some circumstances requiring complex operations that must be accomplished in a limited time frame, such as certain workplace tasks and the operation of machinery and automobiles. The results of these studies may have substantial public health implications and could contribute to both educational and public policy developments.

Teaching Activities
Dr. Hart teaches an undergraduate Drugs & Behavior course (PSYC W2460) and an undergraduate Topics in Neurobiology & Behavior seminar (PSYC G4440) in the Department of Psychology. In addition, Dr. Hart and colleagues in the Division on Substance Abuse teach a graduate level Drugs & Society course (PH 8724) in the School of Public Health.

Training Opportunities
Dr. Hart is a faculty member on Dr. Kleber’s NIDA-funded Substance Abuse Postdoctoral Fellowship grant and in the Columbia University/Hunter College Minority Students Summer Research Program. The research described above provides excellent training opportunities for applicants to the Fellowship and Summer Research programs.

Selected Peer-reviewed Publications
Hart CL, van Gorp WG, Haney M, Foltin RW, Fischman MW: Effects of acute smoked marijuana on complex cognitive performance. Neuropsychopharmacology 25: 757-765, 2001.

Hart CL, Ward AS, Haney M, Nasser J, Foltin RW: Methamphetamine attenuates disruptions in performance and mood during simulated night shift work. Psychopharmacology 169: 42-51, 2003.

Hart CL, Ward AS, Haney M, Foltin RW: Zolpidem-related effects on performance and mood during simulated night shift work. Experimental and Clinical Psychopharmacology 11, 259-268, 2003.