Figure 4. fMRI paradigm.

(A) Before each block, an instruction slide to manipulate subjects’ attention focus was presented (from top to bottom: condition of BB, OB, VB; the offender was labeled as Player A, the victim was labeled as Player B). (B) Each trial starts with the decision phase in which subjects could choose to either costly decrease the offender’s (as shown in this case) or increase the victim’s monetary payoff. After a jittered ISI, subjects were asked to indicate how much of their own endowment they would like to sacrifice in order to change the respective money allocation (transfer phase). A jittered ITI completed the trial. BB = baseline block, OB = offender-focused block, VB = victim-focused block, ISI = inter-stimulus interval, ITI = inter-trial interval.