Spontaneous confabulations after Orbitofrontal damage: The role of temporal context confusion and self-monitoring

Abstract

Orbitofrontal damage or disconnection may lead to spontaneous confabulations, which have the meaning of reality for the patients and occasionally motivate them to act. Spontaneous confabulations are based on a temporal confusion of diverse experiences in memory, i.e. increased temporal context confusion (TCC). Here, we report a patient who suffered orbitofrontal and basal forebrain damage after haemorrhage from an anterior communicating artery aneurysm. The patient was severely amnesic and confabulated spontaneously. His confabulations could always be traced back to actual experiences, an observation indicating a confusion of temporal context in memory. In a recognition task measuring TCC in which all our previous spontaneous confabulators had failed, the patient appeared to use an uncommonly stringent recognition criterion suggestive of attempted, wilful self-monitoring. Only when he was motivated to improve his recognition performance did increased TCC became measurable. In non-confabulating amnesics, the same instructions did not lead to an increase of measurable TCC. We conclude that wilful self-monitoring may complicate the measurement of TCC in a test situation, but cannot prevent its behavioural manifestation, i.e. spontaneous confabulations. We suggest that the orbitofrontal cortex is critical for the maintenance of temporal order in memory by distinguishing between presently ongoing and previously encountered information.