Monetary Incentive Delay (MID Sample Clauses

Monetary Incentive Delay (MID. Task The participants performed a modified version of the Monetary Incentive Delay (MID) task to study neural responses to reward anticipation and reward feedback (Xxxxxxx, Fong, et al., 2001). This event-related task consisted of 66 10-second trials. In each particular trial, participants were presented with one of three cue shapes (cue, 250 ms) denoting whether a target (a white square) would subsequently appear on the left or right side of the screen and whether 0, 2 or 10 points could be won in that particular trial (Figure 1). After a variable delay (4,000-4,500 ms) of fixation on a white crosshair, participants were instructed to respond by pressing a button with their left or right index finger as soon as the target appeared. Feedback on whether and how many points were won during the trial was presented for 1,450 ms after the response. Using a tracking algorithm, task difficulty (i.e. target duration varied between 250 and 400 ms) was individually adjusted such that each participant successfully responded on ~66% of trials. Participants had first completed a practice session outside the scanner (for ~5 minutes), during which they were instructed that for each 5 points won they would receive one food snack in the form of small chocolate candies. Functional MRI BOLD-responses were measured during reward anticipation and reward feedback. The current study used the contrast ‘anticipation high win vs. no win’ and ‘feedback high win vs. no win’. Only successfully ‘hit’ trials were included for analysis.