Emotion regulation deficits in frontotemporal lobar degeneration and Alzheimer's disease

We examined instructed and spontaneous emotion regulation in patients with frontotemporal lobar degeneration (FTLD, N = 32), which presents with profound emotional and personality changes; patients with Alzheimer's disease (AD, N = 17), which presents with profound memory impairment; and neurologically normal controls (N = 25). Participants were exposed to an aversive acoustic startle stimulus (115 dB) under 3 different conditions: (a) unwarned without instructions to down-regulate, (b) warned without instructions to down-regulate, and (c) warned with instructions to down-regulate. In the last 2 conditions, the warning took the form of a 20-s countdown. In all conditions, visible aspects of the startle response were assessed by measuring overall somatic activity and coding emotional facial expressions. FTLD patients, AD patients, and control participants showed similar patterns of down-regulation in somatic activity across the 3 startle trials. However, differences between the 3 groups emerged in the amount of emotional facial behavior expressed in the startle trials. There were no group differences in response in the unwarned condition, indicating that the startle response was intact in the patients. In the warned with instructions condition, both FTLD and AD patients were moderately impaired in down-regulatory ability compared with controls. In the warned without instructions condition, AD patients and normal controls spontaneously down-regulated their emotional responses, but FTLD patients did not. These findings illuminate specific problems that these patients have in the emotional realm.