Increased ventral-striatal activity during monetary decision making is a marker of problem poker gambling severity

Abstract

The aim of this study was to examine the impact of different neural systems on monetary decision making in frequent poker gamblers, who vary in their degree of problem gambling. Fifteen frequent poker players, ranging from non-problem to high-problem gambling, and 15 non-gambler controls were scanned using functional magnetic resonance imaging (fMRI) while performing the Iowa Gambling Task (IGT). During IGT deck selection, between-group fMRI analyses showed that frequent poker gamblers exhibited higher ventral-striatal but lower dorsolateral prefrontal and orbitofrontal activations as compared with controls. Moreover, using functional connectivity analyses, we observed higher ventral-striatal connectivity in poker players, and in regions involved in attentional/motor control (posterior cingulate), visual (occipital gyrus) and auditory (temporal gyrus) processing. In poker gamblers, scores of problem gambling severity were positively associated with ventral-striatal activations and with the connectivity between the ventral-striatum seed and the occipital fusiform gyrus and the middle temporal gyrus. Present results are consistent with findings from recent brain imaging studies showing that gambling disorder is associated with heightened motivational-reward processes during monetary decision making, which may hamper one's ability to moderate his level of monetary risk taking.

Keywords: Decision making; fMRI; problem gambling severity; ventral striatum.

Figure 1

Panel A.1 Coronal view (at Y = 40, 30, 20) of the frontal brain activations observed in controls for the whole brain contrast of deck selection minus baseline. Panel A.2. Coronal view (at Y = 0, −10, −15) of the amygdalar, striatal and insular brain activations observed in controls for the whole brain contrast of disadvantageous deck selection minus advantageous deck selection. Panel B. Coronal view (at y = 50, 15, 5) of the frontal, striatal and insular brain activations observed in poker players for the whole brain contrast of deck selection minus baseline. All contrast maps are thresholded at p < .05, corrected for whole-brain multiple comparisons. Red/Amber color demonstrates areas where subjects show relatively greater activation. The right side of the brain is on the right.

Figure 2

Panel A.1 Coronal view of ventral striatal regions of interest (ROIs). Panel A.2. Compared to controls, poker players showed stronger brain activation in the right ventral striatum (X = 12, Y = 12, Z = 0, k = 10, z = 2.69, at p < .05, corrected) for the contrast of deck selection minus baseline. Panel A.3. Mean parameter estimates (P.E.) extracted from the right ventral striatum for each group separately. Panel B.1. Horizontal view of orbitofrontal ROIs. Panel B.2. Compared to poker players, controls showed stronger brain activation in the left orbitofrontal cortex (X = −32, Y = 28, Z = −12, k = 11, z = 2.72, at p < .05, corrected) for the contrast of deck selection minus baseline. Panel B.3. Mean P.E. extracted from the left orbitofrontal cortex for each group separately. Panel C.1. Horizontal view of dorsolateral prefrontal ROIs. Panel C.2. Compared to poker players, controls showed stronger brain activation in the right dorsolateral prefrontal cortex (X = 36, Y = 30, Z = 28, k = 53, z = 2.96, at p < .05, corrected) for the contrast of deck selection minus baseline. Panel C.3. Mean P.E. extracted from the right dorsolateral prefrontal cortex for each group separately. Error bars are the standard errors of the mean.

Figure 3

Fig. 5. In the poker player group (n = 15), gambling severity was positively correlated with P.E. extracted from the right ventral striatum ROI (Spearmann Rho = .745, p < .001).

Figure 4

As compared with controls, higher ventral striatal connectivity (p < .05, corrected) in poker players in the left posterior cingulate cortex (pathway a.), the occipital fusiform gyrus (pathway b.). and the middle/superior temporal gyrus (pathway c.).