{Reference Type}: Journal Article {Title}: What is the role of spatial processing in the decline of episodic memory in Alzheimer's disease? The "mental frame syncing" hypothesis. {Author}: Serino S;Riva G; {Journal}: Front Aging Neurosci {Volume}: 6 {Issue}: 0 {Year}: 2014 {Factor}: 5.702 {DOI}: 10.3389/fnagi.2014.00033 {Abstract}: The current theories on episodic memory suggest a crucial role of spatial processing for an effective retrieval. For a successful episodic recall, the long-term allocentric scene has to be translated into an egocentric scene. Here, we argue that a crucial role for an episodic retrieval is played by a "mental frame syncing" between two kinds of allocentric representations. This neurocognitive process allows an effective retrieval of our past experiences by synchronizing the allocentric view-point independent representation with the allocentric view-point dependent representation. If the "mental frame syncing" stops, even momentarily, it is difficult to reconstruct a coherent spatial scaffold upon which to effectively retrieve our previous events within an egocentric perspective. This is what apparently happens in Alzheimer's disease: a break in the "mental frame syncing" between these two kinds of allocentric representations, underpinned by damage to the hippocampus, may contribute significantly to the early deficit in episodic memory.