Researchers at Zhejiang University examined the neurological mechanisms behind spending hours on short-video platforms such as Instagram Reels, TikTok and Shorts. In the study published in the journal *NeuroImage*, 56 young adults were observed using advanced brain-scanning methods while watching short videos.
The study focused on the dorsal anterior cingulate cortex (dACC) and dorsolateral prefrontal cortex (dlPFC) in the frontal region of the brain. These regions play a role in attention, decision-making and self-control. According to fMRI scans, a marked decline in activity was observed in both regions when participants watched videos they liked. The researchers determined that the brain reduced cognitive effort by putting its control systems into a kind of “sleep mode” during this content.
The situation was different with videos that participants quickly skipped because they found them boring. While the dACC maintained its normal level of alertness, only a slight decline in activity was observed in the dlPFC. When the expectation of reward decreased, the brain continued to keep the processes of evaluation and initiating action active in order to leave the screen or switch to another video.
The study also revealed a neurochemical finding concerning why people differ in their ability to break away from short-video feeds. Participants with higher levels of glutamate in the dACC while at rest were found to have less suppression of their self-control systems while watching videos. These individuals were less likely to become absorbed in the distracted state created by short videos and found it easier to stop themselves.
The researchers’ findings show that watching short videos for hours cannot be explained solely by “weak willpower” or “lack of discipline.” The low-effort flow created by liked content is associated with the neurological withdrawal of the brain’s self-control networks. The uninterrupted stream of content offered by algorithms also supports this tendency.