Individuals with insula and dACC lesions show impairments in risky decision-making.

<p><b>(a)</b> We used multiple linear regression to examine whether the lesion group was indeed impaired in risky decision-making. Specifically, we set group identity (NC vs lesion), probability of winning the high payoff, and their interaction as predictors of individuals’ gamble choices (proportion of safe choices, P(safe)) on Solo trials. As expected, on average, across all groups, individuals chose the safe option significantly less as the probability of winning the high payoff increased (<i>P</i> = 9.2e−4). In addition, the interaction effect was significant (group (NC vs lesion) × probability interaction: <i>P</i> = 0.022). Specifically, the extent to which individuals chose the safe option less as a function of the gamble’ probability was attenuated in the lesion group compared to NCs. In line with previous reports [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012602#pcbi.1012602.ref020" target="_blank">20</a>,<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1012602#pcbi.1012602.ref021" target="_blank">21</a>], these results suggest that individuals with insula and dACC lesions are impaired in risky decision-making. <b>(b)</b> Lesion participants and NC response times in Solo trials were compared. Individuals with insula or dACC lesions took significantly longer to make a choice compared to NCs (<i>P</i> = 0.026; NC vs insula: <i>P</i> = 0.045; NC vs dACC: <i>P</i> = 0.066), which provides an additional measure indicating disrupted decision-making about risky options. Each point represents an individual participant; Error bars represent s.e.m.</p> <p>(PDF)</p>