Autonomic measures and explicit evaluation of emotional cues in behavioral variant and agrammatic variant of frontotemporal dementia

Previous studies reported significant deficits on emotion recognition over the Frontotemporal Dementia (FTD) spectrum. However, the basis of emotional impairment is still poorly understood, and previously tested only by face recognition approach. In order to assess the status of emotional skills in a group of patients with FTD, we investigated both conscious and explicit evaluation of emotions, by testing valence and arousal self-report measures, and the automatic and unconscious responsiveness to emotional cues, by autonomic measures (Skin Conductance Response, SCR; Heart Rate, HR). Sixteen behavioural variant of FTD patients (bvFTD) and 12 agrammatic variant Primary and Progresive Aphasia (avPPA) patients were tested. Their performance was compared to a group of 14 patients with mild probable Alzheimer’s Disease (AD) and to 20 healthy controls (HC). Patients and HC were required to observe and evaluate affective pictures (IAPS) during autonomic parameters recording (Biofeedback recorder). Whereas a significant partially preserved competence in FTD groups in term of emotion rating and classification was observed, FTD patients showed significant changes in autonomic implicit response. BvFTD and avPPA patients showed lower values of SCR compared with control subjects and patients with AD. The present findings indicate that, within the FTD spectrum, an impairment of emotional recognition can be detected using autonomic measures. In particular, bvFTD showed a nonspecific and generic responsiveness to the emotional cues taking into account the autonomic measures.