Authors:
Thomas Ostermann
1
;
Sibylle Robens
1
;
Petra Heymann
2
;
Sebastian Unger
1
;
Stephan Müller
3
;
Christoph Laske
3
and
Ulrich Elbing
2
Affiliations:
1
Department of Psychology and Psychotherapy, Witten/Herdecke University, Witten, Germany
;
2
University of Applied Sciences Nürtingen-Geislingen, Germany
;
3
Department of Psychiatry and Psychotherapy, Eberhard Karls University, Tübingen, Germany
Keyword(s):
Alzheimer’s Disease, Free Drawing Task, Colour Perception, Mental Status and Dementia Tests.
Abstract:
Cognitive visuo-constructive impairments, which can be detected by drawing tasks are early signs of Alzheimer’s disease (AD). Additionally, several studies revealed deficits in colour perception for patients with AD. In a former analysis of the impact of digital tree-drawing parameters on the screening of early dementia, a logistic regression revealed the number of colours together with the drawing velocity and the number of line widths changes as discrimination characteristics (ROC AUC=0.90, sensitivity=.86, specificity=0.82). To analyse the diagnostic importance of colour variations in drawings, a reanalysis of these data was done with 67 healthy subjects (25 females, mean age 66 ± 10 yrs.) and 56 subjects with early AD (40 females, mean age 73 ± 9 yrs.). The exclusion of colour variables resulted in a good discrimination of healthy and AD (ROC AUC=0.89, specificity=0.89) but in a reduction of sensitivity to .77 compared to the former model. This suggest that the analysis of colour
variations in drawings has an important diagnostic impact.
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