CEREBRAL REPRESENTATION OF ONES OWN PAST - NEURAL NETWORKS INVOLVED IN AUTOBIOGRAPHICAL MEMORY

We studied the functional anatomy of affect-laden autobiographical mem ory in normal volunteers. Using (H2O)-O-15 positron emission tomograph y (PET), we measured changes in relative regional cerebral blood flow (rCBF). Four rCBF measurements were obtained during three conditions: REST, i.e., subjects lay at rest (for control); IMPERSONAL, i.e., subj ects listened to sentences containing episodic information taken from an autobiography of a person they did not know, but which had been pre sented to them before PET scanning (nonautobiographical episodic memor y ecphory); and PERSONAL, i.e., subjects listened to sentences contain ing information taken from their own past (autobiographical episodic m emory ecphory). Comparing IMPERSONAL with REST (nonautobiographical ep isodic memory ecphory) resulted in relative rCBF increases symmetrical ly in both temporal robes including the temporal poles and medial and superior temporal gyri. The same loci, however, with a stronger latera lization to the right hemisphere were activated in the comparison PERS ONAL to REST (autobiographical episodic memory ecphory). In addition, the right temporomesial, right dorsal prefrontal, right posterior cing ulate areas, and the left cerebellum were activated. A comparison of P ERSONAL and IMPERSONAL (autobiographical vs nonautobiographical episod ic memory ecphory) demonstrated a preponderantly right hemispheric act ivation including primarily right temporomesial and temporolateral cor tex, right posterior cingulate areas, right insula, and right prefront al areas. The right temporomesial activation included hippocampus, par ahippocampus, and amygdala. These results suggest that a right hemisph eric network of temporal, together with posterior, cingulate, and pref rontal, areas is engaged in the ecphory of affect-laden autobiographic al information.