Fall 2009 Colloquium Series
Speaker: Janet L. Neiswewander, Ph.D., Department of Psychology, Arizona State University
Title: Social interaction influences drug reward even in rats
Initial experience taking drugs usually occurs in a social context during adolescence or young adulthood, yet very little basic neuroscience research on drug abuse has examined social influences on drug reward and dependence. Laboratory rats, like humans, rely on social interactions for their physical health and psychological well-being, and as such, social interactions in adolescent rats are naturally rewarding. I will present research demonstrating that drug and social rewards interact synergistically in adolescent rats. I will also present data examining neuroendocrine stress responses and neural activation associated with drug and social reward interactions. Finally, the implications of these findings for understanding and treating drug dependence will be discussed.
Speaker: Selena T. Nguyen-Rodriguez, Ph.D., MPH, Institute for Helath Promotion and Disease Prevention, Research Department of Preventive Medicine
Title: Emotional Eating in Minority Youth
Psychosocial and behavioral associations of emotional eating in minority adolescents will be discussed. Data from a larger physical activity intervention study were used to conduct multilevel regression and structural equation model analyses. Results indicate that there is specificity in emotions and foods associated with emotional eating. It also appears that several associations found in European and Caucasian samples as well as in the adult literature generalize to a minority sample of adolescents. Further, stress may be related to emotional eating regardless of weight status. The role of sleep behavior and emotional eating is further studied in a sample of minority children. Results from these studies emphasize the important role of affect as an influential factor in eating behavior. Thus, these findings provide points of focus for obesity interventions that may not have previously received ample attention.
Speaker: Steven J. Mee, M.D., Los Alamitos, California
Title: A Quantitative Scale in the Assessment of Psychological Pain as a Risk Factor for Suicidality
The contributions of psychological pain to depression, suicidality, hopelessness and physical pain are not well-defined, nor have methods been developed to reliably and measurably discriminate between these related experiences. Despite important advances in mood disorder research, nearly 30,000 people commit suicide each year. A convergence of evidence suggests that psychological pain may play a central role in depression and suicide.To date, no reliable and validated instruments have been utilized to assess the incidence or effect on suicidality of psychological pain in patients with major depressive episodes. We developed the Mee-Bunney Psychological Pain Assessment Scale (MBP) to provide rapid, reliable and valid measurement of psychological pain. Our efforts utilizing the MBP to measure psychological pain in depressed and non-depressed subjects have shown that psychological pain adds statistical strength to the prediction of suicide even after controlling for measures of hopelessness and depression. Analysis of raw scores identified a threshold differentiating depressives from controls as well as patients with high and low suicidality potential.
Speaker: Peter Kufahl, Ph.D., Department of Meolecular and Integrative Neurosciences, The Scripps Research Institute
Title: Conditioned Brain Responses to Cocaine: Studies in Human Addicts and Animal Subjects
Cocaine is a widely abused drug that has highly reinforcing properties in humans and animals. Repeated exposure to cocaine results in physiological and neurological adaptations which may eventuate in compulsive drug use. In this seminar I will describe two sets of clinical studies of cocaine addicts and two studies of animal models, all of which use intravenous cocaine as a stimulus. In human addicts, the brain response to cocaine was examined in vivo with functional magnetic resonance imaging (fMRI), demonstrating a pattern of activated brain areas. This experiment was then repeated, with the additional factor of a modified context: in one trial the addict was expecting cocaine stimulus and in the other trial the addict was expecting an injection of vehicle. Subcortical and limbic brain areas reacted similarly to cocaine under the different conditions, but the drug response in higher-order brain areas demonstrated changes in both sensitivity and timing. This result was the first to demonstrate a conditioned response in brain activity in human cocaine addicts, to cocaine reinforcement in one context that was discernable from a response to the same drug in a modified context. The feasibility of measuring cocaine-induced brain activity in the rat was investigated by examining post mortem tissue for the expression of Fos, a protein associated with stimulated neural activity. Since fMRI of rats require the use of anesthetics, the cocaine response of rats under anesthesia induced by different methods (isoflurane and alpha-chloralose) was compared against the cocaine response of conscious, drug-naïve rats. Isoflurane was found to reduce cocaine-elicited Fos expression, whereas alpha-chloralose extinguished it. A follow-up study investigated the effect of isoflurane on the cocaine-elicited Fos response in rats previously conditioned to cocaine, under a locomotor sensitization procedure. The modulatory effects of isoflurane on the Fos expression in conditioned rats were consistent with those found in the cocaine-naïve rats, confirming the regional sensitivity of the brain cocaine response to anesthesia. The animal model was therefore adjudged to be most useful in simulating the effects of cocaine on the limbic and subcortical brain structures of human addicts.
Speaker: Dustin Thoman, Ph.D., Department of Psychology, CSULB
Title: The Social Nature of ‘intrinsic’ Motivation: How talking with others affects the development of interest
People are intrinsically motivated when their behavior is motivated by the anticipated, sought, or actual experience of interest. When most people think or talk about having intrinsic motivation toward some activity, they typically describe the source of that motivation as deriving solely from within themselves (i.e., from some internal source). Most psychological models of intrinsic motivation propose the idea, in some form, that the social context can indirectly facilitate intrinsic motivation, but these models maintain the basic idea that interest arises from the transaction between a person and a given activity at a single point in time. When intrinsic motivation is considered within a continuous self-regulatory process (Sansone & Thoman, 2005), however, the social nature of intrinsic motivation is revealed, as other people may be integral to the interest experience at multiple points in the process—even after the initial transaction. For example, one way other people affect the development of interest for a given activity is through listening behavior in conversations about the activity (Thoman, Sansone, & Pasupathi, 2007). I will describe results from a series of studies (utilizing experimental, quasi-experimental, and survey methodologies) that converge to support the proposition that social interaction plays an important role in the experience and development of activity interest even beyond the immediate activity experience. Conclusions are discussed in terms of how these results inform our understanding of the social processes that contribute specifically to students’ development of educational and career interest and identities.