Prefrontal Cortex Responses to Conflicting Information.

Over time, we develop event schemas or scripts that shape our expectations about what typically happens in certain contexts. However, even after forming a memory about a certain event, we are often exposed to related information about that same event at later points in time. This additional information sometimes causes one to have to re-evaluate the interpretation of the original event. Over a two-day fNIRS experiment, participants were exposed to events that were subsequently updated with schema-congruent or schema-incongruent additional details. These schema-incongruent additional details make those events more fitting to another schema than originally was the case, meaning that participants would need to dissociate that event from the original schema and re-integrate it with another schema. The fNIRS results showed higher oxygenated hemoglobin (HbO) concentrations in the prefrontal cortex (PFC)-which indicates enhanced PFC activation-for events updated with schema-congruent compared to schema-incongruent details. When specifically looking at those events that were updated with schema-incongruent details, our results suggest that dissociating an event from the original schema and re-integrating it with another schema was accompanied by an initial PFC decrease early in the trial followed by a PFC increase later in the trial. This was a distinctly different pattern compared to trials in which participants failed to re-integrate the event with another schema, which showed delayed PFC increase with lower amplitude and no initial PFC decrease. Our findings provide insight into how people process and integrate conflicting information.