Strong Emotions Synchronize Brain Activity

Group consciousness and mob psychology have been experienced by many but explained by few. At the Aalto University in Helsinki, Finland, a research team has produced evidence that shared experiences producing an emotional reaction can lead to synchronized brain activity.

Feeling strong emotions makes peoples’ brains ‘tick together’

Research team at Aalto University and Turku PET Centre has revealed how experiencing strong emotions synchronizes brain activity across individuals.

Human emotions are highly contagious. Seeing others’ emotional expressions such as smiles triggers often the corresponding emotional response in the observer. Such synchronization of emotional states across individuals may support social interaction: When all group members share a common emotional state, their brains and bodies process the environment in a similar fashion.

Researchers at Aalto University and Turku PET Centre have now found that feeling strong emotions makes different individuals’ brain activity literally synchronous.

Emotions promote social interaction by synchronizing brain activity across individuals


Sharing others’ emotional states may facilitate understanding their intentions and actions. Here we show that networks of brain areas “tick together” in participants who are viewing similar emotional events in a movie. Participants’ brain activity was measured with functional MRI while they watched movies depicting unpleasant, neutral, and pleasant emotions. After scanning, participants watched the movies again and continuously rated their experience of pleasantness–unpleasantness (i.e., valence) and of arousal–calmness. Pearson’s correlation coefficient was used to derive multisubject voxelwise similarity measures [intersubject correlations (ISCs)] of functional MRI data. Valence and arousal time series were used to predict the moment-to-moment ISCs computed using a 17-s moving average. During movie viewing, participants’ brain activity was synchronized in lower- and higher-order sensory areas and in corticolimbic emotion circuits. Negative valence was associated with increased ISC in the emotion-processing network (thalamus, ventral striatum, insula) and in the default-mode network (precuneus, temporoparietal junction, medial prefrontal cortex, posterior superior temporal sulcus). High arousal was associated with increased ISC in the somatosensory cortices and visual and dorsal attention networks comprising the visual cortex, bilateral intraparietal sulci, and frontal eye fields. Seed-voxel–based correlation analysis confirmed that these sets of regions constitute dissociable, functional networks. We propose that negative valence synchronizes individuals’ brain areas supporting emotional sensations and understanding of another’s actions, whereas high arousal directs individuals’ attention to similar features of the environment. By enhancing the synchrony of brain activity across individuals, emotions may promote social interaction and facilitate interpersonal understanding.