The role of egocentric-updating in episodic memory

International audienceThe relation between episodic memory and spatial function is generally conceptualised through a linking process. Episodic memory binds various elements in a specific spatial and temporal context. It has thus been proposed that during retrieval, disparate neocortical elements could be re-associated into a coherent episode due to an allocentric spatial representation (i.e., coding for object-to-object relations, independently of the individual's position) maintained within the hippocampal formation (Burgess, Becker, King, & O'Keefe, 2001, Nadel & Moscovitch, 1998). However, in apparent discrepancies with a pure allocentric coding, the phenomenological experience is characterised by an autonoetic consciousness occurring while the original first perspective view on the original event is rein- stated. We propose that autonoetic consciousness could be linked to an individual's attribution from a fluency in processing egocentric-updating spatial information (i.e., monitoring of position, orientation and movement of one's body in relation with spatial elements) during retrieval.We will present two type of evidence in favour of this hypothesis. On the neuropsychological side, our study of short-term spatial performance of two pure bi-hippocampal amnesic patients (developmental or acquired amnesia) indicates a processing deficit in egocentric updating and not in allocentric ones, provided that testing conditions disentangle these two types of coding.With respect to behavioural and fMRI data, we will present experimental results showing that episodic remembering appears to be more dependent on egocentric-updating processes than of allocentric one