Dr. Christine Hughes, Graduate Coordinator & Associate Professor
I have several lines of behavior-analytic research in which graduate and undergraduate students participate. Currently, my research involves the experimental analysis of behavior in rats and pigeons in areas of translational science.
Punishment: Timeout from Positive Reinforcement. Although timeout often is used in homes and schools to decrease unwanted behavior, there is still the need for research on variables that alter timeout's effectiveness. Currently, we are examining the effects of different timeout durations on behavior maintained by different rates of reinforcement. I also am interested in effects of different types of timeouts, how timeout affects other unpunished behaviors, and how other reinforcement variables (e.g., deprivation) alter timeout's effects. Future research will extend these variables to the examination of response cost. Given that many children are taking prescription medications, such as Ritalin, and experience timeout, I also am interested in effects of drugs on behavior punished by timeout and/or response cost.
Drugs and Impulsivity. Drugs of abuse can affect decision making. Stimulant drugs (e.g., amphetamine) often decrease "impulsive" choices, that is, instead of choosing an immediate, but small reinforcer ("impulsivity"), subjects tend to choose a delayed but larger reinforcer ("self-control") more often. Other drugs tend to increase impulsive choices. In our lab, we investigate both acute and chronic effects of drugs such as methylphenidate (i.e., Ritalin), amphetamine, morphine, and oxycodone on impulsive choices. In addition, we examine effects of drug withdrawal on impulsive behavior and how components of impulsive choices - reinforcement delay and magnitude - contribute to the drugs' effects.
Drug Tolerance and Dependence. Many drugs of abuse disrupt ongoing behavior and when these drugs are repeatedly administered tolerance may develop to this behavioral disruption. That is, a given dose of the drug no longer produces its initial effect and a larger dose of the drug now is required to produce that effect. The development of tolerance to these disruptive effects of the drug may make it more likely that an individual continues taking and abusing the drug. I am interested in how behavioral variables, such as, response effort, unit price, magnitude of reinforcement, and response/reinforcement dependency, affect the development of tolerance to drugs such as morphine and amphetamine.
Over the last few years, I have taught Psy 417: Psychology of Learning, Psy 515: Small-n Research Design, and both undergraduate and graduate seminars in Impulsivity. I also have taught Psy 350: Principles of Behavior Change and Psy 355: Introduction to Experimental Psychology. I enjoy working with undergraduate students on Directed Individual Studies (Psy 491) and Honors Theses Psy 499) in which they can participate in research in our lab.
Rodewald, A. R.., Hughes, C. E., & Pitts, R. C. (2010). Development and maintenance of choice in a dynamic environment. Journal of the Experimental Analysis of Behavior, 94, 175-195.
Rodewald, A. R.., Hughes, C. E., & Pitts, R. C. (2010). Choice in a variable environment: Effects ofd-amphetamine on sensitivity to reinforcement. Behavioural Pharmacology, 84, 460-464.
Maguire, D. R., Rodewald, A. M., Hughes, C. E., & Pitts, R. C. (2009). Rapid acquisition of preference in concurrent schedules: Effects of d-amphetamine on sensitivity to reinforcement amount. Behavioural Processes, 81, 238-243.
Thomas, L. D., Hughes, C. E., & Pitts, R. C. (2009). Effects of d-amphetamine on behavior maintained by signaled and unsignaled delays to reinforcement. Behavioural Processes, 81, 264-269.
TA,W-M, Pitts, R. C., Hughes, C. E., McLean, A. P., & Grace, R. C. (2008). Rapid acquisition of preference in concurrent chains: Effects of d-amphetamine on sensitivity to reinforcement delay. Journal of the Experimental Analysis of Behavior, 89, 71-91.
Bennett, J. A., Hughes, C. E., & Pitts, R. C. (2007). Effects of methamphetamine on response rate: A microstructural analysis.Behavioural Processes, 75, 199-205.
Maguire, D. R., Hughes, C. E., & Pitts, R. C. (2007). Rapid acquisition of preference in concurrent schedules: Effects of reinforcement amount. Behavioural Processes, 75, 213-219.
Hughes, C. E., Sigmon, S. C., Pitts, R. C., & Dykstra, L. A. (2005). Morphine tolerance as a function of ratio schedule: Response requirement or unit price? Journal of the Experimental Analysis of Behavior, 83, 281-296.
Hughes, C. E., Ariely, D., & Eckerman, D. A. (1999).The Joy of Experimental Psychology. (2nd Ed.) Dubuque, IA: Kendall/Hunt Publishing.