Short videos deactivate brain regions for cognitive control

A new study published in the journal NeuroImage finds that watching short-form videos, such as those on TikTok, Instagram Reels, and YouTube Shorts, temporarily deactivates key brain regions responsible for cognitive control. The research, led by scientists at Zhejiang University, used fMRI and spectroscopy to observe the brains of 56 young adults as they freely watched videos under 30 seconds. When participants viewed videos they found attractive, activity in the dorsal anterior cingulate cortex (dACC) and dorsolateral prefrontal cortex (dlPFC) significantly decreased, regions involved in impulse control, decision-making, and attention regulation Source: Clarin. This reduction suggests the brain enters a more automatic, "flow"-like state, making it harder to stop scrolling Source: Infobae.

Key findings

• The study observed that preferred videos led to a clear decrease in activity in both dACC and dlPFC, while uninteresting videos left activity near resting levels Source: El Colombiano.
• Higher levels of the neurotransmitter glutamate in the dACC were associated with less suppression during attractive videos, indicating individual differences in self-control Source: Infobae.
• Although activity in these regions decreased, communication between them increased, possibly reflecting a coordinated emotional response that enhances the immersive experience Source: El Colombiano.

Broader context

Separately, a study in Nature Human Behaviour found that opening a social media account before age 14 is linked to a drop in academic performance, equivalent to half a year of learning loss in language and math Source: El Colombiano. While the NeuroImage study shows a correlation, not causation, the findings add to growing concerns about the cognitive effects of digital media consumption.