Research Interests
In order to adapt to its environment, an animal must be sensitive to the consequences of its actions and be able to modify its behavior in order to gain access to desired commodities while avoiding events that are harmful or aversive. It is the flexibility of the instrumental or goal-directed components of human behaviour that allows us to develop new behavioural strategies to control events in our environment and satisfy our needs. The adaptive quality of this flexibility becomes most clear when these processes break down as they do in a number of psychiatric disorders including addiction. The goal of my research is to provide fundamental information about the behavioural and neural determinants of goal-directed action and the transition to automatic/habitual performance. This work will also provide considerable insight into the development and maintenance of addictive behaviors and may aid the development of treatment strategies to reverse such behaviors.
Current Projects
Goal-directed versus Habit Learning
Goal-directed actions depend on knowledge of the association between a response and the consequences or outcome of that response. However, with extended training as behaviour becomes more efficient and automatic, the importance of the outcome of performance decreases and the role of environmental stimuli in guiding behaviors is thought to increase (Balleine et al., 1995; Colwill and Rescorla, 1986; Dickinson, 1985; Dickinson and Balleine, 1994; Dickinson et al., 2002). The precise time course of this transition has not been fully characterized, nor has it been assessed whether such a time course differs for responses reinforced with natural vs. drug rewards.
Further, the neural systems that control goal-directed vs. habitual responding are only beginning to be understood. Previous work has shown that corticolimbic circuitry is importantly involved in governing goal-directed actions (e.g., Corbit et al, 2001; Corbit & Balleine 2003) and several recent studies have demonstrated a critical role for the dorsal striatum in habit formation and stimulus-directed responding (e.g., Yin et al., 2004; Corbit & Janak, 2007b; Corbit & Janak 2010). This leads to the interesting hypothesis that the brain regions controlling reward-seeking behaviors change over the course of training. Ongoing studies are examining this hypothesis using reversible inactivation techniques and a parallel series of studies is using electrophysiological recording to examine changes in neural activity during reward-seeking behaviors such as outcome devaluation and Pavlovian-instrumental transfer. I am particularly interested in neural responses that correspond to changes in behavioral responses in the presence of reward-related stimuli or following changes in reward value.
Extinction Learning
Preventing relapse is a major challenge for the treatment of drug abuse. Exposure to drug-associated environmental stimuli, even following long periods of abstinence, can contribute to craving and relapse to drug use. A major goal of our research is to develop means for reducing the powerful influence of drug-associated stimuli. Our approach is to use behavioral and pharmacological methods to enhance the learning that occurs during extinction training in order to reduce the susceptibility to future recovery of the extinguished cocaine-seeking behaviors. We use an animal model of relapse to test the hypothesis that deepening the learning that occurs during extinction of cocaine- or alcohol-associated stimuli will reduce the future ability of these stimuli to precipitate drug-seeking behavior. By determining behavioral and pharmacological methods to enhance the stability and longevity of extinction learning, we hope to provide insight into the development of better therapies for drug addiction that will be less susceptible to relapse.
Publications
For reprints of any of the following articles, please feel free to contact me at
Hogarth L, Balleine BW, Corbit, LH, Killcross S. (2013). Associative learning mechanisms underpinning the transition from recreational drug use to addiction. Ann N Y Acad Sci., 1282, 12-24.
Corbit, L.H. & Janak, P.H. (2012). Habitual alcohol seeking: Time course and the contribution of subregions of the dorsal striatum. Biological Psychiatry. 72, 389-95.
Janak, P.H., Bowers, M.S., & Corbit, L. H. (2011).Compound stimulus presentation and the norepinephrine reuptake inhibitor atomoxetine enhance long-term extinction of cocaine-seeking behavior. Neuropsychopharmacology, Epub ahead of print.
Corbit, L.H. & Balleine, B.W. (2011). The general and outcome-specific forms of Pavlovian-instrumental transfer are differentially mediated by the nucleus accumbens core and shell. The Journal of Neuroscience, 31, 11786-94.
Janak PH, Corbit LH. (2011). Deepened extinction following compound stimulus presentation: noradrenergic modulation. Learning & Memory, 18, 1-10.
Corbit LH, Janak PH. (2010). Posterior dorsomedial striatum is critical for both selective instrumental and Pavlovian reward learning. European Journal of Neuroscience, 31, 1312-21.
Corbit, L.H. & Janak, P.H. (2007). Inactivation of the lateral but not medial dorsal striatum eliminates the excitatory impact of Pavlovian stimuli on instrumental responding. The Journal of Neuroscience, 27, 13977-13981.
Corbit, L.H. & Janak, P.H. (2007). Inactivation of the lateral but not medial dorsal striatum eliminates the excitatory impact of Pavlovian stimuli on instrumental responding. The Journal of Neuroscience, 27, 13977-13981.
Corbit, L.H., Janak, P.H., & Balleine, B.W. (2007). General and outcome-specific forms of Pavlovian-instrumental transfer: the effect of shifts in motivational state and inactivation of the ventral tegmental area. European Journal of Neuroscience, 26, 3141-3149.
Corbit, L.H. & Janak, P.H. (2007). Ethanol-associated cues produce general Pavlovian-instrumental transfer. Alcoholism: Clinical and Experimental Research, 31, 766-774.
Corbit, L.H. & Balleine, B.W. (2005). Double dissociation of the effects of lesions of basolateral and central amygdala on the outcome-specific and general forms of Pavlovian-instrumental transfer. The Journal of Neuroscience, 25, 962-970.
Corbit, L.H. & Balleine, B.W. (2003). The role of the prelimbic cortex in instrumental conditioning. Behavioral Brain Research, 146, 145-157.
Corbit, L.H., Muir, J.L, & Balleine, B.W. (2003). Lesions of mediodorsal thalamus and anterior thalamic nuclei produce dissociable effects on instrumental conditioning in rats. The European Journal of Neuroscience, 18, 1-10.
Corbit, L.H. & Balleine, B.W. (2003). Instrumental and Pavlovian incentive processes have dissociable effects on components of a heterogeneous instrumental chain. The Journal of Experimental Psychology: Animal Behavior Processes, 29, 99-106.
Corbit, L.H., Ostlund, S.B., & Balleine, B.W. (2002). Cell body lesions of entorhinal cortex and electrolytic, but not cell body lesions of dorsal hippocampus reduce sensitivity to degradation of the instrumental contingency in rats. The Journal of Neuroscience, 22, 10976-10984.
Corbit, L.H., Muir, J.L, & Balleine, B.W. (2001). The role of the nucleus accumbens in instrumental conditioning: Evidence for a functional dissociation between accumbens core and shell. The Journal of Neuroscience, 21, 3251-3260.
Corbit, L.H. & Balleine, B.W. (2000). The role of the hippocampus in instrumental conditioning. The Journal of Neuroscience, 20, 4233-4239.
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