Dynamics and diversity of heart rate responses to a disaster motion picture.

Emotions are dynamic neuropsychophysiological processes that guide behavior and serve as crucial signals during social interactions. Measuring their highly individual temporal dynamics is an unresolved challenge, but the coupling of autonomic and central nervous processes offers a promising approach. We present a feasible approach to study changes in heart rate during emotions and demonstrate a link to empathy. We investigated the interindividual similarity and temporal dynamics of heart rate responses to an emotive motion picture. Forty healthy participants watched "The Impossible" (109 min; Hermida Muñiz et al., 2012) while their heart rate was recorded. Interindividual concordance of heart rate responses was analysed using agglomerative hierarchical clustering analyses to distinguish response patterns throughout the movie and during six highly emotive scenes. This revealed multiple response patterns during emotive scenes. Second, we analysed how changes in heart rate are linked to self-reported empathy. We found that the extent of changes in heart rate is positively linked to trait and state empathy. During specific scenes, this relationship was only visible when individuals with homogeneous heart rate response patterns were observed, but not across discordant response patterns. In conclusion, our results demonstrate that heart rate responses to complex social stimuli are not uniform. Therefore, research should favour statistical procedures with the potential to detect interindividual differences. The approach presented in our study allows us to depict interindividual similarity and diversity in emotional autonomic responses and emphasizes the key role of empathy in emotional experiences.

Mesial temporal lobe epilepsy diminishes functional connectivity during emotion perception.

OBJECTIVES: Unilateral mesial temporal lobe epilepsy (MTLE) has been associated with impaired recognition of emotional facial expressions. Correspondingly, imaging studies showed decreased activity of the amygdala and cortical face processing regions in response to emotional faces. However, functional connectivity among regions involved in emotion perception has not been studied so far. METHODS: To address this, we examined intrinsic functional connectivity (FC) modulated by the perception of dynamic fearful faces among the amygdala and limbic, frontal, temporal and brainstem regions. Regions of interest were identified in an activation analysis by presenting a block-design with dynamic fearful faces and dynamic landscapes to 15 healthy individuals. This led to 10 predominately right-hemispheric regions. Functional connectivity between these regions during the perception of fearful faces was examined in drug-refractory patients with left- (n=16) or right-sided (n=17) MTLE, epilepsy patients with extratemporal seizure onset (n=15) and a second group of 15 healthy controls. RESULTS: Healthy controls showed a widespread functional network modulated by the perception of fearful faces that encompassed bilateral amygdalae, limbic, cortical, subcortical and brainstem regions. In patients with left MTLE, a downsized network of frontal and temporal regions centered on the right amygdala was present. Patients with right MTLE showed almost no significant functional connectivity. A maintained network in the epilepsy control group indicates that findings in mesial temporal lobe epilepsy could not be explained by clinical factors such as seizures and antiepileptic medication. CONCLUSION: Functional networks underlying facial emotion perception are considerably changed in left and right MTLE. Alterations are present for both hemispheres in either MTLE group, but are more pronounced in right MTLE. Disruption of the functional network architecture possibly contributes to deficits in facial emotion recognition frequently reported in MTLE.