Recognition of facial expressions of different emotional intensities in patients with frontotemporal lobar degeneration.

Behavioural problems are a key feature of frontotemporal lobar degeneration (FTLD). Also, FTLD patients show impairments in emotion processing. Specifically, the perception of negative emotional facial expressions is affected. Generally, however, negative emotional expressions are regarded as more difficult to recognize than positive ones, which thus may have been a confounding factor in previous studies. Also, ceiling effects are often present on emotion recognition tasks using full-blown emotional facial expressions. In the present study with FTLD patients, we examined the perception of sadness, anger, fear, happiness, surprise and disgust at different emotional intensities on morphed facial expressions to take task difficulty into account. Results showed that our FTLD patients were specifically impaired at the recognition of the emotion anger. Also, the patients performed worse than the controls on recognition of surprise, but performed at control levels on disgust, happiness, sadness and fear. These findings corroborate and extend previous results showing deficits in emotion perception in FTLD.