To generate the results presented in the main text we created a GLM that included categorical events at the time of incentive presentation and separate events for each combination of motor task conditions (incentive level, difficulty, performance). The incentive presentation event was modeled with a duration lasting the length of incentive presentation

(2–5 s), whereas the motor task event was modeled with a fixed duration of 2 s. Because there were six incentive levels ($0, $5, $25, $50, $75, $100), two difficulty levels (easy, hard), and two performance outcomes (successful, unsuccessful), this resulted in 24 categorical events to model all condition combinations of the motor task. Including the incentive presentation event, a grand total of 25 categorical events were modeled. We also included incentive level as a parametric modulator at the time of the incentive presentation event. In addition, regressors modeling the head motion BGJ398 manufacturer as derived from the affine part of the realignment produce were included in the model. With this model we tested brain areas in which activity was correlated with incentive level at the time of incentive presentation.

Carfilzomib solubility dmso This was done by creating contrasts with the aforementioned parametric modulator for incentive at the time of incentive presentation. We also examined areas in which activity was correlated with incentive level at the time of the motor task. This was done by creating linear contrasts for the motor task conditions at the varying incentive levels (separated among difficulty levels and performance Megestrol Acetate outcomes). To increase statistical power these

contrasts (Figure 4) were computed for trials collapsed across difficulty levels; and to control for actual performance they were computed for only those trials in which participants were successful. We created a separate GLM to test for differences in brain activity between performance outcomes (i.e., unsuccessful and successful trials) during the motor task, and activity showing an interaction between incentives and performance during the motor task. This model included a categorical event at the time of incentive presentation and separate events at the time of the motor task for unsuccessful and successful trials. Each of these categorical regressors included a parametric modulator corresponding to the level of incentive presented. The main effect regressors for unsuccessful and successful trials were subtracted to create contrasts showing the differences between successful and unsuccessful trials. To create the interaction contrast (Figure 7) we subtracted the incentive parametric modulators, at the time of the motor task, for unsuccessful and successful trials. To estimate participants’ loss aversion we used a parametric analysis. We expressed participants’ utility function u for monetary values x as u(x)={xx≥0λxx<0.