Open Access

Thomas Ostermann, Sibylle Robens, Petra Heymann, Sebastian Unger, Stephan Müller, Christoph Laske, Ulrich Elbing

• 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 forCognitive 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.…