The role of temporal lobe epilepsy in the Construction and Elaboration of Autobiographical Memories: a preliminary analysis

Autobiographical memory (AM) is supported by a network of brain areas among which the hippocampal complex is supposed to play a predominant role. It recently emerged that the right and left hippocampus may differently sustain the two phases of autobiographical memory retrieval (i.e. construction and elaboration). In the current study we recruited 16 patients with unilateral temporal lobe epilepsy (TLE), that also presented hippocampal sclerosis, and we evaluated their performance in both phases of AM processing with the Autobiographical and Public Memory Test, comparing them with a group of healthy volunteers. Our aim was to explore differences in the retrieval of autobiographical and public memories during the construction and elaboration phases. Moreover, all participants also underwent an MRI session, so that we could observe the structural brain correlates of the two phases with a Voxel-Based Morphometry (VBM) analysis. Results showed that, in line with previous literature, the recollection of autobiographical memories is characterised by higher specificity, reliving, vividness and emotional intensity compared to public memories. Furthermore, it emerged that TLE does affect the two retrieval phases, depending on the side of the hippocampal damage. In particular, both patient groups were associated with reduced specificity, whereas only left TLE patients showed a heightened recollection, probably due to the loss of low-recollective memories because of the sclerosis. Finally, preliminary results on the VBM analysis are discussed. Our results, even if preliminary and conducted on a limited sample, highlight the different contribution of the right and left hippocampus in autobiographical memory retrieval.