A study published in the journal NeuroImage found that watching short-form videos, such as Instagram Reels and YouTube Shorts, redirects brain activity away from cognitive control and toward emotional engagement and instant gratification, according to the research.
The researchers said this shift in neural processing could contribute to excessive use of the platforms and a decline in self-control among some viewers.
How the study was carried out
To investigate the effect, researchers examined a group of 56 young people as they freely watched short videos. The video library used in the study contained 160 clips split into five categories: actions performed by a single person, interactions between multiple people, pet videos, gaming footage and natural landscapes. Participants were told to watch the clips naturally while keeping head movement to a minimum.
Brain regions linked to self-control were suppressed
The study found that two regions of the brain showed significant deactivation when participants watched their preferred videos all the way through. The first, the dorsal anterior cingulate cortex, known as the dACC, is linked to cognitive control, decision-making and detecting conflict. The second, the dorsolateral prefrontal cortex, or dlPFC, is associated with logic, focus and planning, helping people think before acting and solve problems.
At the same time, connectivity between the cortex and the prefrontal cortex increased while participants watched the videos, particularly the ones they preferred.
Glutamate and individual differences
According to the study, excessive use and deep immersion in preferred short videos are associated with reduced activity in the brain's cognitive control network. The researchers linked individual differences in this reduced activation to glutamate metabolism.
Glutamate is the brain's main excitatory neurotransmitter and plays a role in memory and learning. It is also responsible for umami, the fifth basic taste.
Not a uniform response
The study suggested the brain does not react to short videos in the same way every time. Instead, the response depends on whether the content is perceived as relevant or enjoyable, an adaptation that involves both communication between brain regions and the glutamate-linked chemical system, the researchers said.
