Watching short videos on TikTok and Instagram temporarily reduces activity in brain regions responsible for self-control, according to new research. In a study of 56 people averaging 23 years old, participants watched nearly 24-second clips and rated whether they enjoyed them.
Videos that participants liked significantly decreased activity in areas involved in cognitive control, while disliked videos had a smaller effect. The findings suggest the brain shifts temporarily toward automatic, low-effort processing during passive viewing rather than losing self-control capacity long-term. This change appears to be a natural response to engaging content rather than evidence of lasting cognitive decline.