documented an association between episodic counterfactual
thinking and key regions within the core network, and further
provided information concerning how brain activity is modulated
by the likelihood of a counterfactual outcome. In this study, prior
to scanning participants recalled specific episodes characterized
by either a positive or a negative outcome. During scanning, participants
recalled some of these episodes, and also engaged in
three different types of counterfactual simulations regarding
other episodes. In the positive condition, they imagined what
would have happened if a reported event whose outcome was
negative instead had a positive outcome (i.e., upward counterfactual);
in the negative condition, they imagined what would have
happened if a reported event whose outcome was positive instead
had a negative outcome (i.e., downward counterfactual); and in the
peripheral condition, they imagined an alternative way in which
the experienced outcome could have been brought about by
changing a peripheral detail of the event. Participants also provided
ratings of the subjective likelihood of the counterfactual
events, thus allowing comparison of brain activity associated with
counterfactual events that participants rated as likely versus
those that they rated unlikely. Brain activity in these conditions
was compared with activity from a control task, where participants
constructed sentences that compared the sizes of different
objects