title: Making sense of theory of mind and paranoia: the psychometric properties and reasoning requirements of a false belief sequencing task.
abstract: INTRODUCTION. This study used Item-Response Theory (IRT) to model the psychometric properties of a false belief picture sequencing task. Consistent with the mental time travel hypothesis of paranoia, we anticipated that performance on this deductive theory of mind (ToM) task would not be associated with the presence of persecutory delusions but would be related to other clinical, cognitive, and demographic factors. METHOD. A large (N=237) and diverse clinical and nonclinical sample differing in levels of depression and paranoid ideation performed 2 ToM tasks: the false belief sequencing task and a ToM stories task that was used to assess the validity of the false belief sequencing task as a measure of ToM. RESULTS. A unidimensional IRT model was found to fit the data well. Latent ToM ability as measured by the false belief sequencing task was negatively related with age and positively with IQ. In contrast to the ToM stories measure, there was no association between clinical diagnosis or symptoms and false belief picture sequencing after controlling for age and IQ. CONCLUSIONS. In line with mental time travel hypothesis of paranoia (Corcoran, 2010 ), performance on this deductive nonverbal ToM task is not related to the presence of paranoid symptoms. This measure is best suited for assessing ToM functioning where participants' performance falls just short of the average latent ToM ability. Furthermore, it is sensitive to the effects of increasing age and decreasing IQ.
authors.affiliation: Division of Psychiatry, School of Community Health Sciences, University of Nottingham, UK. rhiannon.corcoran@nottingham.ac.uk
authors.forename: Rhiannon
authors.initials: R
authors.lastname: Corcoran
authors.forename: Richard P
authors.initials: RP
authors.lastname: Bentall
authors.forename: Georgina
authors.initials: G
authors.lastname: Rowse
authors.forename: Rosanne
authors.initials: R
authors.lastname: Moore
authors.forename: Sinead
authors.initials: S
authors.lastname: Cummins
authors.forename: Nigel
authors.initials: N
authors.lastname: Blackwood
authors.forename: Robert
authors.initials: R
authors.lastname: Howard
authors.forename: Nick M
authors.initials: NM
authors.lastname: Shryane
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D003071:Cognition / Q000502:physiology; D003702:Delusions / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D008875:Middle Aged; D008960:Models, Psychological; D015233:Models, Statistical; D009483:Neuropsychological Tests; D010259:Paranoid Disorders / Q000523:psychology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D011594:Psychometrics; D012959:Socioeconomic Factors; D056345:Theory of Mind / Q000502:physiology*; D014888:Wechsler Scales; D055815:Young Adult