During the development of addiction, the pursuit of drugs of abuse, such as alcohol, becomes progressively less goal-directed and progressively more habitual coming under the control of internal and external states and stimuli. Understandably, therefore, recent theory and research on alcoholism has started to focus on the habit learning process and its behavioral and neural bases. It is important, however, to distinguish habitual drug-seeking from other forms of habitual behavior. Under normal conditions, habit learning can be highly adaptive;habits allow us and other animals to relegate the control of routine behavioral responses to a system that uses few cognitive resources freeing up this limited capacity for tasks that need greater monitoring. Unlike goal-directed actions that are quickly acquired and flexibly deployed, habits are usually slowly acquired, stimulus-bound and inflexible. Nevertheless, their deployment can be rapidly suppressed when conditions change. Driving, cycling, even walking would be very dangerous activities if we couldn't quickly and reliably suppress these habits as and when circumstances change to navigate around an obstacle. In contrast, habitual drug seeking is pathological;drug exposure appears both to increase the rate of habit acquisition and the influence of drug associated contexts and cues on their performance. Furthermore, despite the heavy emphasis on habit processes in current research, a distinguishing feature of habitual drug seeking is the addicts'loss of executive and behavioral control over the habit;drug seeking persists even in the face of severe negative consequences. The compulsive pursuit of alcohol can be viewed, therefore, as the product of two interacting processes: (i) an alcohol-induced increment in the acquisition of habitual alcohol seeking and (ii) an alcohol-induced decrement in the addict's ability to exert control over the habit in the face of persistent, sometimes extreme negative feedback. It is important to recognize, however, that these effects of alcohol exposure extend beyond alcohol seeking and appear to have an effect on decision-making and adaptive behavioral control more generally. It is likely, therefore, that alcohol exposure produces extensive changes in the larger neural systems that control the acquisition and performance of goal-directed and habitual actions. Given these considerations, the broad objective of the current project is to assess the effect of alcohol exposure on the behavioral and neural determinants of (i) goal directed learning, (ii) habit learning and (iii) the processes that control the degree to which these learning processes are implemented in performance.
The transition from casual drinking to compulsive alcohol seeking may stem from alcohol's tendency to disrupt the cognitive and behavioral processes that guide action selection and decision making more generally. In instrumental conditioning, the behavioral processes, and the corresponding neural systems, responsible for goal-directed action selection and habitual performance have been relatively well characterized. The broad, long-term objective of the current project is, therefore, to investigate how exposure to alcohol affects the neural systems that control goal-directed and habitual instrumental learning processes.
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