Chronic marijuana users (MJ Users) perform poorly on the Iowa Gambling Task (IGT), a complex decision-making task in which monetary wins and losses guide strategy development. This functional magnetic resonance imaging (MRI) study sought to determine if the poor performance of MJ Users was related to differences in brain activity while evaluating wins and losses during the strategy development phase of the IGT. MJ Users (16) and Controls (16) performed a modified IGT in an MRI scanner. Performance was tracked and functional activity in response to early wins and losses was examined. While the MJ Users continued to perform poorly at the end of the task, there was no difference in group performance during the initial strategy development phase. During this phase, before the emergence of behavioral differences, Controls exhibited significantly greater activity in response to losses in the anterior cingulate cortex, medial frontal cortex, precuneus, superior parietal lobe, occipital lobe and cerebellum as compared to MJ Users. Furthermore, in Controls, but not MJ Users, the functional response to losses in the anterior cingulate cortex, ventral medial prefrontal cortex and rostral prefrontal cortex positively correlated with performance over time. These data suggest MJ Users are less sensitive to negative feedback during strategy development.
|Number of pages||9|
|Journal||Psychiatry Research - Neuroimaging|
|State||Published - Jan 30 2011|
Bibliographical noteFunding Information:
This work was supported by the National Institute of Drug Abuse grants DA007246 (MJW), DA020074 (LJP), and DA06634 (LJP). The authors thank Mack D. Miller, Hilary R. Smith and Thomas J.R. Beveridge for their comments on this manuscript and Marla Torrence for her assistance in recruitment and processing of the participants. None of the authors have any financial conflict of interest in the performance or publication of this research.
- Functional MRI
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Radiology Nuclear Medicine and imaging
- Psychiatry and Mental health