One size does not fit all: Face emotion processing impairments in
semantic dementia, behavioural-variant frontotemporal dementia and Alzheimer's
disease are mediated by distinct cognitive deficits
Affiliations: Neuropsychology Unit, Royal Prince Alfred Hospital,
Camperdown, NSW, Australia | School of Psychology, University of Sydney, Sydney,
NSW, Australia | Neuroscience Research Australia, Sydney, NSW,
Australia | School of Medical Sciences, University of New South
Wales, Sydney, NSW, Australia
Abstract: Patients with frontotemporal dementia (both behavioural variant
[bvFTD] and semantic dementia [SD]) as well as those with Alzheimer's disease
(AD) show deficits on tests of face emotion processing, yet the mechanisms
underlying these deficits have rarely been explored. We compared groups of
patients with bvFTD (n=17), SD (n=12)
or AD (n=20) to an age- and education-matched group of
healthy control subjects (n=36) on three face emotion
processing tasks (Ekman 60, Emotion Matching and Emotion Selection) and found
that all three patient groups were similarly impaired. Analyses of covariance
employed to partial out the influences of language and perceptual impairments,
which frequently co-occur in these patients, provided evidence of different
underlying cognitive mechanisms. These analyses revealed that language
impairments explained the original poor scores obtained by the SD patients on
the Ekman 60 and Emotion Selection tasks, which involve verbal labels.
Perceptual deficits contributed to Emotion Matching performance in the bvFTD
and AD patients. Importantly, all groups remained impaired on one task or more
following these analyses, denoting a primary emotion processing disturbance in
these dementia syndromes. These findings highlight the multifactorial nature of
emotion processing deficits in patients with dementia.
