Risky Gains Task.

<p>In two subsequent gambles on 96 trials, subjects could gamble the safe option (cash in 20 cents) for double or nothing, to gain 40 or, in the potential second gamble, 80 cents (“risky” decisions). Positive values needed to be collected within their respective 1sec presentation window. 54 trials were predefined as rewarded (+20, +40, +80), 24 as punished 40 trials (-40) and 18 as punished 80 (-80) trials. Overall totals were displayed on top after a given trial, so that subjects could monitor their performance and monetary wins and losses. Decision phase regressors for fMRI analysis were defined as lasting from the onset of the trial until the subject had made a response, or, in the case of a response latency greater than 1sec, until the subject was presented with a negative value. The baseline regressor encompassed the time to initiation of the trial and the time after presenting the outcome, and also included the null trials that are interspersed.