One step too far: social cerebellum in norm-violating navigation.

Area of Science:

• Neuroscience
• Social Cognition
• Cerebellar Function

Background:

• Social norms are fundamental to guiding human interactions and behavior.
• The posterior cerebellum is implicated in processing sequential dynamics, crucial for understanding actions.
• Detecting deviations from social norms is vital for successful social navigation.

Purpose of the Study:

• To investigate the posterior cerebellum's role in detecting social norm conformity and deviation.
• To identify neural mechanisms underlying the perception of norm-violating social actions.

Main Methods:

• Participants observed goal-directed navigation tasks with norm-following and norm-violating trajectories.
• Functional neuroimaging (fMRI) was used to examine brain activity during observation and reproduction of trajectories.
• Comparisons were made against non-social and non-sequential control conditions.

Main Results:

• Observing norm-violating behaviors significantly engaged the posterior cerebellum (Crus 2) and temporoparietal junction (TPJ).
• The parahippocampal gyrus (PHG) showed greater activation for norm-violating compared to norm-following social sequences.
• Reproducing norm-violating trajectories activated the left cerebellar Crus 2 and right PHG more than norm-following ones.

Conclusions:

• The posterior cerebellum plays a key role in detecting transgressions of social norms during navigation.
• Neural mechanisms involving the cerebellum and mentalizing network signal deviations from anticipated social sequences.
• Findings highlight the cerebellum's contribution to social cognition and norm adherence.