title: Humour processing in frontotemporal lobar degeneration: A behavioural and neuroanatomical analysis.
abstract: Humour is a complex cognitive and emotional construct that is vulnerable in neurodegenerative diseases, notably the frontotemporal lobar degenerations. However, humour processing in these diseases has been little studied. Here we assessed humour processing in patients with behavioural variant frontotemporal dementia (n = 22, mean age 67 years, four female) and semantic dementia (n = 11, mean age 67 years, five female) relative to healthy individuals (n = 21, mean age 66 years, 11 female), using a joint cognitive and neuroanatomical approach. We created a novel neuropsychological test requiring a decision about the humorous intent of nonverbal cartoons, in which we manipulated orthogonally humour content and familiarity of depicted scenarios. Structural neuroanatomical correlates of humour detection were assessed using voxel-based morphometry. Assessing performance in a signal detection framework and after adjusting for standard measures of cognitive function, both patient groups showed impaired accuracy of humour detection in familiar and novel scenarios relative to healthy older controls (p < .001). Patient groups showed similar overall performance profiles; however the behavioural variant frontotemporal dementia group alone showed a significant advantage for detection of humour in familiar relative to novel scenarios (p = .045), suggesting that the behavioural variant syndrome may lead to particular difficulty decoding novel situations for humour, while semantic dementia produces a more general deficit of humour detection that extends to stock comedic situations. Humour detection accuracy was associated with grey matter volume in a distributed network including temporo-parietal junctional and anterior superior temporal cortices, with predominantly left-sided correlates of processing humour in familiar scenarios and right-sided correlates of processing novel humour. The findings quantify deficits of core cognitive operations underpinning humour processing in frontotemporal lobar degenerations and suggest a candidate brain substrate in cortical hub regions processing incongruity and semantic associations. Humour is a promising candidate tool with which to assess complex social signal processing in neurodegenerative disease.
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Camilla N
authors.initials: CN
authors.lastname: Clark
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom; London School of Hygiene and Tropical Medicine, University of London, London, United Kingdom.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Nicholas
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Susie M D
authors.initials: SM
authors.lastname: Henley
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Downey
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Ione O
authors.initials: IO
authors.lastname: Woollacott
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Hannah L
authors.initials: HL
authors.lastname: Golden
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Phillip D
authors.initials: PD
authors.lastname: Fletcher
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Mummery
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Schott
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Rohrer
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Crutch
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, University College London, London, United Kingdom. Electronic address: jason.warren@ucl.ac.uk.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Warren
mesh_terms: D000368:Aged; D003071:Cognition; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D057180:Frontotemporal Dementia / Q000473:pathology / Q000523:psychology*; D057174:Frontotemporal Lobar Degeneration / Q000473:pathology / Q000523:psychology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000473:pathology*; D014925:Wit and Humor as Topic / Q000523:psychology*
keywords: Cartoons; Frontotemporal dementia; Frontotemporal lobar degeneration; Humor; Incongruity; Semantic dementia