ИСТИНА

In probabilistic conditions, people choose low-payoff alternatives on some trials, thus failing to maximize their payoffs. We suggest that such behaviour implies exploration of task rules by choosing risky options instead of exploiting more rewarding alternatives. We hypothesized that, first, during exploration the importance of feedback on risky trials may augment feedback salience. Second, exploratory strategy could develop gradually and, therefore, a decision to make an exploratory choice may affect brain response to the feedback on trials preceding risky choices. Namely, we expected to observe indications of increased feedback salience on trials with risky choices and those of decreased feedback importance on trials preceding risky choices. We investigated beta power (16-30 Hz) in the magnetoencephalographic data from 62 healthy participants performing a two-choice probabilistic gambling task involving monetary gains and losses. We found increases in beta power 600-800 ms following losses in risky choices, possibly implying a more articulated response to missed rewards. On trials preceding risky choices, we identified a decrease in beta power 800 ms following rewards. This effect might reflect a change in decision-making strategy and a shift towards cognitive flexibility and exploration.