Normative data for Emotion Hexagon test and frequency of impairment in behavioral variant frontotemporal dementia, Alzheimer's disease and Huntington's disease

Social cognitive functions such as Theory of Mind, empathy and emotion recognition can be impaired in dementia spectrum disorders, especially in diseases with prominent frontal dysfunction. The Emotion Hexagon test (EHT) is a short test of basic emotion recognition. As with other social cognitive tests, normative data for this test is sparse. The aim of this study was to present regression-based normative data for the EHT. Further, we wished to investigate the frequency of impairment in patients with the behavioral variant of frontotemporal dementia (bvFTD, N = 11), Alzheimer's disease (AD, N = 44) and Huntington's disease (HD, N = 52) when using regression-based normative data. The results documented that age (but not gender or education) had a significant effect on EHT score. The effect of age had numerical impact on expected scores in persons older than 60 years. Normative data (including percentile estimates) are presented. The EHT is sensitive to impairment in both bvFTD and HD, where more than 80% of patients had lower scores than expected. In both groups, 54% of patients fell below the 5th percentile-estimate, and in HD 65% fell below the 10th percentile-estimate. In the AD group 25% fell below the 10th percentile-estimate, and 14% fell below the 5th percentile-estimate. In conclusion, very low scores are typically associated with HD and bvFTD, but very poor performances can also be found in other diseases such like AD. Hopefully, the normative data presented and the documentation of their validity in clinical practice is a useful tool for clinicians.