Theory of Mind and social reserve: Alternative hypothesis of progressive Theory of Mind decay during different stages of Alzheimer's disease.
Although Theory of Mind (ToM) is thought to be impaired in Alzheimer's disease (AD), it remains unclear whether this impairment is linked to the level of task complexity, the heterogeneity of the studied patients, or the implication of executive dysfunctions. To elucidate this point, 42 AD patients, divided into two subgroups [moderate AD (mAD) patients (n = 19) and early AD (eAD) patients (n = 23)], and 23 matched healthy older subjects (HO) were enrolled. All participants were given (1) a false-belief task (cognitive ToM), (2) a revised version of the "Reading the Mind in the Eyes" test (affective ToM), and (3) a composite task designed to assess ToM abilities with minimal cognitive demands. Participants were also given executive tasks assessing inhibition, shifting, and updating processes. We observed a significant impairment of cognitive and composite ToM abilities in eAD patients compared with mAD patients. There was no impairment of affective ToM. Stepwise regression revealed that measures of global efficiency and executive functions (EFs) were the best predictors of progressive decay of ToM scores. These results indicate that cognitive aspects of ToM are more sensitive to AD progression than affective tasks. They also show that ToM abilities are more affected by dementia severity than by task complexity. One explanation of our results is the presence of compensatory mechanisms (social reserve) in AD.
a Laboratoire de Psychologie LPPL (UPRES EA 4638) , LUNAM Université, University of Angers , Angers , France.|b Laboratoire de Psychologie et de NeuroCognition (LPNC, CNRS UMR 5105) , University of Savoie , Chambéry , France.
Rafika
R
Fliss
a Laboratoire de Psychologie LPPL (UPRES EA 4638) , LUNAM Université, University of Angers , Angers , France.|c Department of Neurology , University Hospital of Angers , Angers , France.|d Centre Mémoire de Ressources et de Recherche , University Hospital of Angers , Angers , France.
Didier
D
Le Gall
a Laboratoire de Psychologie LPPL (UPRES EA 4638) , LUNAM Université, University of Angers , Angers , France.|c Department of Neurology , University Hospital of Angers , Angers , France.|d Centre Mémoire de Ressources et de Recherche , University Hospital of Angers , Angers , France.
Frédérique
F
Etcharry-Bouyx
c Department of Neurology , University Hospital of Angers , Angers , France.|d Centre Mémoire de Ressources et de Recherche , University Hospital of Angers , Angers , France.
Valérie
V
Chauviré
e Inserm, U1077 , Université de Caen Normandie, Ecole Pratique des Hautes Etudes, Centre Hospitalier Universitaire , Caen , France.
Béatrice
B
Desgranges
a Laboratoire de Psychologie LPPL (UPRES EA 4638) , LUNAM Université, University of Angers , Angers , France.|c Department of Neurology , University Hospital of Angers , Angers , France.|d Centre Mémoire de Ressources et de Recherche , University Hospital of Angers , Angers , France.
Philippe
P
Allain
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000523:psychology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology*; D018450:Disease Progression; D056344:Executive Function; D005149:Facial Expression; D005260:Female; D006801:Humans; D007600:Judgment; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012919:Social Behavior; D018709:Statistics, Nonparametric; D056345:Theory of Mind / Q000502:physiology*
Alzheimer’s disease; Compensatory mechanisms; Executive functions; Social cognition; Social reserve; Theory of Mind