On the same wavelength: The relationship between neural synchrony and cognitive ability during movie watching in late childhood and early adolescence.

Cognitive development in late childhood and adolescence occurs alongside increasingly complex environments. To examine how cognitive abilities relate to neural processing of naturalistic experiences, we analyzed fMRI data from 309 children and adolescents (ages 7-15; majority White) in the Healthy Brain Biobank. Participants watched a 10-minute clip of Despicable Me during scanning and completed the WISC. Intersubject correlation (ISC) was used to measure brain synchrony during viewing. Adolescents (11-15) with higher cognitive scores showed greater ISC in default mode and frontoparietal networks. In contrast, younger children (7-11) with high scores showed increased between-subject synchrony only in somatosensory regions. These findings suggest age- and cognition-related differences in how children and adolescents process complex, real-world stimuli.