Figure 4

A schematic showing a trial of FCNef. On each trial, a participant saw an equals sign on the screen above the fixation point for 14 s. This was followed by a plus sign on the screen above the fixation point for 42 s. The participant had been instructed to simply maintain fixation on the fixation cross and not think about anything too deeply when the equals sign was on the screen. They had been instructed to do their best to ‘do something with their brain’ to get the best feedback possible when the plus sign was on the screen. Of the 42 s that the plus sign was on the screen, the first 40 s is considered the “induction period”. The data from the first 2 s of the induction period were discarded to somewhat account for the hemodynamic delay and the data from the next 38 s were used in the calculation of FC. Unbeknown to the participant (because nothing on the screen changed), FC calculation took place during the “calculation period”, which was the final 2 s that the plus sign was on the screen. Based on this FC calculation, feedback was then presented on the screen in the form of a green circle. The larger the green circle the more money the participant would receive for that trial. The participant had been instructed to do their best to make the green circle larger than the red circle that was also shown on the screen. The circumference of the red circle represented the participant's baseline FC (which had been calculated based on neural activity from the induction periods of SHAM FCNef from Day 0).