Prolonged Visual Facial Grasp in Frontotemporal Dementia

Abstract

Abstract.Background: Gaze and eye contact is a critical aspect of social interaction. Patients with behavioral variant frontotemporal dementia (bvFTD) may exhibit abnormally prolonged stare toward human faces. Objective: To study characteristics of social gaze in patients with bvFTD compared to age and education matched-patients with early-onset Alzheimer's disease (eAD) and healthy controls (HC). Method: Fifty picture stimuli were presented to each participant (bvFTD = 12, eAD = 18, HC = 13). Each stimuli contained two properties: face (facial versus non-facial) and valence (positive, negative, and neutral). The "facial" stimuli contained human faces. The participants Visual Fixation Time (VFT) was measured for each picture stimuli of interest (per facial expressions on the Facial Action Coding System). A linear mixed-effects regression model with participant-level of random effects was used to compare VFTs between groups. Results: The patients with bvFTD showed significantly prolonged VFTs to faces than the patients with eAD and the HC, regardless of valence (all p < 0.01). There were no differences in VFTs for non-facial stimuli between patients with bvFTD and eAD. However, patients with bvFTD and eAD had significantly prolonged VFTs to negative non-facial stimuli than the HC (p = 0.006 and 0.019, respectively). Conclusion: Patients with bvFTD exhibited a prolonged stare toward human faces. This prolonged visual facial grasp may contribute to the disturbed social interactions of patients with bvFTD and can help distinguish them from those with Alzheimer's disease and other conditions. Additionally, both dementia groups tended to stare at negative stimuli whether faces or non-faces.

Decreased emotion recognition and reduced focus on facial hallmarks in behavioral variant frontotemporal dementia compared to primary psychiatric disorders and controls

“…The finding that focus on the eyes seems less susceptible for impairment (compared to the mouth) might be explained by the primary role of the eyes in human communication. Patients with bvFTD are known to present with a prolonged, sometimes inappropriate, visual facial grasp during social interaction [32], and an increased environmental dependence [33]. These conducts are presumably due to a release of primitive reflexes and may be seen as forms of (social) disinhibition, in which focus on the eyes is not restrained.…”

Affective Empathy in Behavioral Variant Frontotemporal Dementia: A Meta-Analysis

“…The tasks-based studies demonstrate clear problems with bvFTD patients' capacity to connect emotively with the world around them. These studies should be further replicated as they may produce insight to the individual behaviors within affective empathy, such as the lack of reciprocity in communication and the disconcerting prolongation of eye gaze ( 56 ). These compliment the robust inventories that speak to the day to day loss of affect connection which is a significant problem for family members of bvFTD ( 57 ).…”