Sex-related differences in neural activity during risk taking: an fMRI study

Abstract

This study explored sex effects on the process of risk-taking. We observed that the female participants (n = 10) showed stronger activation in the right insula and bilateral orbitofrontal cortex (OFC) than did the male participants (n = 12) while they were performing in the Risky-Gains task. The female participants also showed stronger activations in the precentral, postcentral, and paracentral regions after receiving punishment feedback. In addition, the strength of neural activity in the insula correlated with the rate of risky behaviors for the female participants but not for the male participants. Similarly, the percent signal changes in the right OFC correlated negatively with the rate of selecting risky choices for the female group. These findings strongly suggest a sex-related influence modulating brain activity during risk-taking tasks. When taking the same level of risk, relative to men, women tend to engage in more neural processing involving the insula and the OFC to update and valuate possible uncertainty associated with risk-taking decision making. These results are consistent with the value-based decision-making model and offer insights into the possible neural mechanisms underlying the different risk-taking attitudes of men and women.

Figure 1.

Schematic diagram of the Risky-Gains task.

Figure 2.

Results of the ROI analyses. The activation map shows the activation in the predefined regions, the insula and the OFC, on a standard template, and the bar charts show the plot of percent signal change for the risky versus safe-response contrast in female and male participants. No significantly stronger activation was revealed for the male participants than for the female participants. Right (R) is right. L = left hemisphere; R = right hemisphere; x, y, z in Montreal Neurological Institute coordinates. Error bars show standard error of means.

Figure 3.

Results of the ROI analyses comparing activations in the insula and the OFC between female and male participants. x, y, z in Montreal Neurological Institute coordinates.

Figure 4.

Whole-brain analysis comparing sex effects on risky versus safe-response contrast and punishment feedback versus risky-response contrast at a voxel-wise intensity threshold of P < 0.001 corrected at a cluster level of 10 voxels. No significantly stronger activation was revealed for the male participants than for the female participants. L = left hemisphere; R = right hemisphere; x, y, z in Montreal Neurological Institute coordinates.

Figure 5.

Scatter plot between the rate of risky responses and percent signal change in the right insula.

Figure 6.

Scatter plot between the rate of risky responses and percent signal change in the left insula.

Figure 7.

Whole-brain analysis showing stronger brain activation in the female participants than in the male participants on a) punished-then-risky versus safe responses; b) punished-then-risky versus safe-then-risky responses; c) punished-then-risky versus risky-then-risky responses; d) risky-then-risky versus safe responses; and e) risky-then-risky versus safe-then-risky responses at a voxel-wise intensity threshold of P < 0.001 corrected at a cluster level of 10 voxels. L = left hemisphere; R = right hemisphere; x, y, z in Montreal Neurological Institute coordinates.

Figure 8.

Scatter plot between the rate of risky responses after receiving punishment feedback (i.e., punished-then-risky response) and its percent signal change in the right OFC.

Figure 9.

Scatter plot between the rate of risky responses after making a risky response (i.e., risky-then-risky response) and its percent signal change in the left insula.