title: Determinants of theory of mind performance in Alzheimer's disease: A data-mining study.
abstract: Whether theory of mind (ToM) is preserved in Alzheimer's disease (AD) remains a controversial subject. Recent studies have showed that performance on some ToM tests might be altered in AD, though to a lesser extent than in behavioural-variant Frontotemporal Dementia (bvFTD). It is however, unclear if this reflects a genuine impairment of ToM or a deficit secondary to the general cognitive decline observed in AD. Aiming to investigate the cognitive determinants of ToM performance in AD, a data-mining study was conducted in 29 AD patients then replicated in an independent age-matched group of 19 AD patients to perform an independent replication of the results. 44 bvFTD patients were included as a comparison group. All patients had an extensive neuropsychological examination. Hierarchical clustering analyses showed that ToM performance clustered with measures of executive functioning (EF) in AD. ToM performance was also specifically correlated with the executive component extracted from a principal component analysis. In a final step, automated linear modelling conducted to determine the predictors of ToM performance showed that 48.8% of ToM performance was significantly predicted by executive measures. Similar findings across analyses were observed in the independent group of AD patients, thereby replicating our results. Conversely, ToM impairments in bvFTD appeared independent of other cognitive impairments. These results suggest that difficulties of AD patients on ToM tests do not reflect a genuine ToM deficit, rather mediated by general (and particularly executive) cognitive decline. They also suggest that EF has a key role in mental state attribution, which support interacting models of ToM functioning. Finally, our study highlights the relevancy of data-mining statistical approaches in clinical and cognitive neurosciences.
authors.affiliation: Department of Neurology, Manipal Hospitals, Bangalore, India.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Ramanan
authors.affiliation: Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Leonardo Cruz
authors.initials: LC
authors.lastname: de Souza
authors.affiliation: Aix Marseille Université, CNRS, LPL, Aix-en-Provence, France.
authors.forename: Noémie
authors.initials: N
authors.lastname: Moreau
authors.affiliation: Centre Psychiatrie & Neurosciences, Sainte-Anne, Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Sarazin
authors.affiliation: Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Antônio L
authors.initials: AL
authors.lastname: Teixeira
authors.affiliation: Norwich Medical School, University of East Anglia, UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Allen
authors.affiliation: Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Henrique C
authors.initials: HC
authors.lastname: Guimarães
authors.affiliation: Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Caramelli
authors.affiliation: Centre de Référence Démence Rares, Pitié-Salpêtrière, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 975, Paris, France; Sorbonne Universités, Paris VI, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Dubois
authors.affiliation: Norwich Medical School, University of East Anglia, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Hornberger
authors.affiliation: Norwich Medical School, University of East Anglia, UK; Centre de Référence Démence Rares, Pitié-Salpêtrière, Paris, France; Institut National de la Santé et de la Recherche Médicale, UMRS 975, Paris, France; Sorbonne Universités, Paris VI, France. Electronic address: maxime.bertoux@cantab.net.
authors.forename: Maxime
authors.initials: M
authors.lastname: Bertoux
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D057225:Data Mining; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D056345:Theory of Mind
keywords: Alzheimer's disease; Behavioral variant frontotemporal dementia; Data driven; Data mining; Theory of mind