Abstract
One of the most critical components to social behavior is the recognition of the emotional states of others. Consequently, numerous cortical and subcortical brain regions are involved in the processing of emotional signals from conspecifics. To gain causal evidence regarding the role these areas play in emotion perception, we investigated emotion processing in patients diagnosed with the behavioral variant of fronto-temporal degeneration (bvFTD), combining behavioral testing and structural and resting state fMRI imaging in patients, with functional imaging in young healthy volunteers. 14 bvFDT patients performed a behavioral emotion recognition task (4 emotions) using dynamic body expressions generated by motion morphing as stimuli. The task involved a first emotion detection, and a second emotion categorization stage. Compared to controls, patients were significantly impaired in both tasks, whereas they showed no difference in performance in a control task testing emotionally neutral motion morphs between walking and running. Interestingly, performance in the two tasks correlated with distinct regional atrophy: Gray matter volume in the left anterior temporal lobe (ATL) correlated with emotion detection, whereas atrophy in the left inferior frontal gyrus (IFG) correlated with emotion categorization performance in patients. Investigating emotion decoding performance using MVPA analysis of functional data from healthy controls performing the same task in the scanner supported the potentially crucial role of the two regions. Whereas both, ATL and IFG, allowed for decoding of emotional stimuli compared to neutral stimuli (emotion detection), only IFG allowed decoding of which emotion was shown (emotion categorization). Resting state fMRI analysis comparing patients with age matched controls showed reduced connectivity between ATL and IFG, ATL and mid and posterior temporal regions, IFG and insular and IFG and amygdala. These results highlight the specific functional roles that the anterior temporal lobe and the inferior frontal gyrus play in emotion perception from body movements.
Meeting abstract presented at VSS 2016