Autonoetic consciousness in Alzheimer's disease: neuropsychological and PET findings using an episodic learning and recognition task.
OBJECTIVE
This study aims to map in patients with mild Alzheimer's disease (AD) the correlations between resting-state brain glucose utilization measured by FDG-PET and scores reflecting autonoetic consciousness in an episodic learning and recognition task.


METHODS
Autonoetic consciousness, that gives a subject the conscious feeling to mentally travelling back in time to relive an event, was assessed using the Remember/Know (R/K) paradigm.


RESULTS
AD patients provided less R responses (reflecting autonoetic consciousness) and more K ones (indicating the involvement of noetic consciousness) than healthy controls. Correct recognitions associated with a R response correlated with the metabolism of frontal areas bilaterally whereas those associated with a K response mainly correlated with the metabolism of left parahippocampal gyrus and lateral temporal cortex.


CONCLUSIONS
These data show that recollection is impaired in AD and recognition is more based on a feeling of familiarity than in controls. In addition, the findings of our correlative approach indicate that the impairment of episodic memory is mainly subserved by the dysfunction of frontal areas and of the hippocampal region.
Rauchs
Géraldine
G
Inserm-EPHE-Université de Caen E0218 and GIP Cyceron, Laboratoire de Neuropsychologie, CHU Avenue Côte de Nacre, 14033 CAEN cedex, France.
Piolino
Pascale
P
Mézenge
Florence
F
Landeau
Brigitte
B
Lalevée
Catherine
C
Pélerin
Alice
A
Viader
Fausto
F
de la Sayette
Vincent
V
Eustache
Francis
F
Desgranges
Béatrice
B
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001931:Brain Mapping; D003243:Consciousness / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D013223:Statistics as Topic; D018709:Statistics, Nonparametric
D019788:Fluorodeoxyglucose F18