The aim of this study is to characterize the deficit in critical components of personal identity (self-consciousness and social cognition) in patients with Alzheimer's disease (AD) and fronto-temporal lobar dementia (FTLD), compared to healthy elderly, combining a neuropsychology and multi-podal neuroimaging study.

We posit that the alteration of some aspects of self-consciousness (autobiographical memory, nosognosia, metacognition) and social cognition (theory of mind and facial) results in personality changes in the patients, primarily due to the alteration of self-consciousness in AD and to social cognition in FTLD.

Inclusion Criteria:

• AD (McKhann et al, 1984 and Dubois et al, 2007) or FTLD (Neary et al, 1998 or Rascovsky et al, 2011)
• MMSE > or = 18
• Relative avaible

Exclusion Criteria:

• Contraindication to MRI
• Major depression
• Other central neurological condition