Aims: To use functional magnetic resonance imaging (fMRI) to investigate the neural circuitry behind effort-related valuation and motivation in a population of alcohol-dependent participants and healthy controls.
Methods: Seventeen alcohol-dependent participants and a comparison group of 17 healthy control participants completed an effort-based motivation paradigm during an fMRI scan, in which they were required to exert effort at varying levels in order to earn a monetary reward.
Results: We found that alcohol-dependent participants were less motivated during trials requiring high levels of effort. The whole-brain fMRI analysis revealed that alcohol-dependent participants displayed an increased blood-oxygen-level dependent (BOLD) signal during low and unknown effort cues in the dorsal and ventral striatum compared with healthy controls.
Conclusion: These findings provide the first evidence that alcohol-dependent participants and healthy controls differ in their effort-based valuation and motivation processing. Alcohol-dependent participants displayed a hyperactive mesolimbic reward circuitry recruited by non-drug rewards, potentially reflecting a sensitization to reward in this patient population.
Published by Oxford University Press on behalf of Medical Council on Alcohol 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.