Abstract
The Iowa Gambling Task (IGT) involves exploratory learning via rewards and penalties, where most advantageous task performance
requires subjects to forego potential large immediate rewards for small longer-term rewards to avoid larger punishments. Pathological
gambling (PG) subjects perform worse on the IGT compared to controls, relating to their persistence at high risk decisions
involving the continued choice of potential large immediate rewards despite experiencing larger punishments. We wished to
determine if neural processing of risk and reward within striatal and frontal cortex is associated with this behaviour observed
in PG. Functional magnetic resonance imaging (fMRI) was used to assess brain activity in response to a computerized version
of the IGT. Thirteen male PG subjects with no active comorbidities were compared to 13 demographically matched control subjects.
In agreement with previous behavioural studies, PG subjects performed worse on the IGT and made more high-risk choices compared
to controls, particularly after experiencing wins and losses. During high-risk gambling decisions, fMRI demonstrated that
PG subjects exhibited relatively increased frontal lobe and basal ganglia activation, particularly involving the orbitofrontal
cortex (OFC), caudate and amygdala. Increased activation of regions encompassing the extended reward pathway in PG subjects
during high risk choices suggests that the persistence of PG may be due to the increased salience of immediate and greater
potential monetary rewards relative to lower monetary rewards or potential future losses. Whether this over activation of
the reward pathway is associated with the development of PG warrants further investigation.
requires subjects to forego potential large immediate rewards for small longer-term rewards to avoid larger punishments. Pathological
gambling (PG) subjects perform worse on the IGT compared to controls, relating to their persistence at high risk decisions
involving the continued choice of potential large immediate rewards despite experiencing larger punishments. We wished to
determine if neural processing of risk and reward within striatal and frontal cortex is associated with this behaviour observed
in PG. Functional magnetic resonance imaging (fMRI) was used to assess brain activity in response to a computerized version
of the IGT. Thirteen male PG subjects with no active comorbidities were compared to 13 demographically matched control subjects.
In agreement with previous behavioural studies, PG subjects performed worse on the IGT and made more high-risk choices compared
to controls, particularly after experiencing wins and losses. During high-risk gambling decisions, fMRI demonstrated that
PG subjects exhibited relatively increased frontal lobe and basal ganglia activation, particularly involving the orbitofrontal
cortex (OFC), caudate and amygdala. Increased activation of regions encompassing the extended reward pathway in PG subjects
during high risk choices suggests that the persistence of PG may be due to the increased salience of immediate and greater
potential monetary rewards relative to lower monetary rewards or potential future losses. Whether this over activation of
the reward pathway is associated with the development of PG warrants further investigation.
- Content Type Journal Article
- Category Original Paper
- Pages 1-14
- DOI 10.1007/s10899-011-9278-5
- Authors
- Yuri Power, Department of Psychiatry, University of Calgary, C203, 1403-29 Street NW, Foothills Medical Centre, Calgary, AB T2N 2T9, Canada
- Bradley Goodyear, Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
- David Crockford, Department of Psychiatry, University of Calgary, C203, 1403-29 Street NW, Foothills Medical Centre, Calgary, AB T2N 2T9, Canada
- Journal Journal of Gambling Studies
- Online ISSN 1573-3602
- Print ISSN 1050-5350