Using functional MRI alongside proton magnetic resonance spectroscopy (H-MRS), the research team examined 56 young adults while they freely watched short video clips inside an MRI scanner. Both the dorsal anterior cingulate cortex (dACC) and the dorsolateral prefrontal cortex (dlPFC) showed reduced activity specifically when participants watched clips they liked enough to view to completion. Cognitive control helps people balance immediate pleasures against longer-term goals, and impairments in this system are linked to conditions such as depression, anxiety, ADHD, and addiction. Short-video platforms present rapid, algorithmically curated streams that are built for continuous, low-effort consumption.
Prior behavioral research has tied both internet addiction and smartphone addiction to weaker self-control, and separate neuroimaging work has documented disruptions to reward and cognitive-control circuits in people with behavioral addictions. Despite this, few studies had directly tested whether the act of watching entertaining short videos itself suppresses the brain’s cognitive control regions. The Zhejiang University team set out to answer that question, along with a second one: what neurochemical factors might explain why this suppression varies from person to person?
