People with short-video addiction show altered brain responses during decision-making

A new brain imaging study suggests that people who report symptoms of addiction to short-form video platforms—such as TikTok or Instagram Reels—may be less sensitive to financial losses and make faster, more impulsive decisions. The findings, published in NeuroImage, show that this lower sensitivity to losses is associated with distinct brain activation patterns during decision-making, particularly in regions involved in evaluating rewards and guiding behavior.

Behaviors associated with addiction—such as substance use and gambling—are linked to a reduced ability to weigh potential costs and benefits. Individuals with these behaviors often prioritize short-term rewards over long-term consequences. While much attention has been paid to these traditional forms of addiction, the rise of short-form video platforms has introduced a new category of potentially harmful digital habits. These apps provide a continuous stream of highly tailored content that can trigger dopamine release and encourage repeated use.

“Short-form video addiction is a global public health threat—with users in China spending 151 minutes daily on average, and 95.5% of internet users engaged. This high-intensity ‘instant reward’ consumption not only impairs attention, sleep, and mental health but also increases depression risk,” said study author Qiang Wang, a professor of psychology at Tianjin Normal University.

“While substance addictions (e.g., gambling, alcohol) consistently show reduced sensitivity to losses, how short-form video addiction alters the brain’s evaluation of ‘risk vs. loss’ was virtually unexplored. Thus, we pioneered an integration of computational modeling (DDM) and neuroimaging (fMRI) to uncover: 1). Whether addicts undervalue long-term costs of usage (e.g., time loss, health risks); 2). How neural evidence accumulation speed and motor-sensory networks drive such decision biases.”

Specifically, the research team wanted to understand whether individuals who report more symptoms of short-form video addiction also show reduced “loss aversion”—a psychological tendency to give greater weight to losses than to equivalent gains. Loss aversion is generally considered a protective feature of decision-making, as it helps people avoid risky behavior. Previous studies have found that people with gambling disorder, alcohol dependence, and certain drug addictions show reduced loss aversion, but little was known about how this pattern might emerge in non-substance behavioral addictions, like compulsive short-video use.

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To explore this question, the researchers recruited 36 university students aged 18 to 24, all of whom completed a widely used measure of short-video addiction symptoms. This questionnaire asked how often participants experienced cravings, difficulty controlling their use, or negative consequences from excessive short-video watching. All participants also underwent functional magnetic resonance imaging (fMRI) while performing a mixed gambling task, which involved accepting or rejecting hypothetical gambles that offered varying combinations of potential monetary gains and losses. The researchers designed the task to measure how sensitive each participant was to potential losses compared to gains.

The team used a behavioral modeling technique known as the drift diffusion model (DDM) to break down the decision-making process into measurable components. This model estimates how quickly a person accumulates evidence in favor of one decision or another, how much evidence they require to make a choice, and how long non-decision processes (like sensory encoding or motor response) take. It allows researchers to distinguish between people who are slow and cautious versus those who make hasty decisions with less deliberation.

The analysis revealed a link between short-video addiction symptoms and lower loss aversion. In other words, participants who scored higher on the addiction scale were less deterred by the possibility of financial losses and more likely to take risks. These individuals also showed faster accumulation of decision evidence, suggesting a tendency to make quicker, more impulsive choices. This link between addiction symptoms, reduced sensitivity to loss, and accelerated decision-making was statistically robust and remained significant even after accounting for differences in age, sex, and socioeconomic background.

To better understand the brain mechanisms underlying these behavioral patterns, the researchers examined neural activity during the decision-making task. They found that participants with higher short-video addiction symptoms showed reduced activation in a brain region called the precuneus during gain-related decisions. This part of the brain is associated with self-reflection, cognitive control, and value-based evaluation. In contrast, these participants showed increased activation in the cerebellum and the postcentral gyrus—areas involved in motor control and sensory processing—when evaluating potential losses.

Follow-up statistical tests showed that brain activity in the precuneus played a mediating role in the relationship between short-form video addiction symptoms and both loss aversion and decision speed. In other words, reduced activation in this region helped explain why individuals with more addiction symptoms were less sensitive to losses and made quicker decisions. Additional analyses using a method called inter-subject representational similarity analysis further revealed that people with similar patterns of short-form video addiction symptoms also had similar brain activation profiles in cognitive control and motor-related networks during gain and loss processing.

“Studies have found that people with high levels of short-form video addiction are less sensitive to loss and more impulsive in decision-making (evidence accumulates faster),” Wang told PsyPost. “This suggests that they may underestimate the long-term costs of swipe short videos (e.g. time waste, sleep problems), and focus more on immediate pleasure.”

“From a neural perspective, abnormal activity of the brain’s cognitive control network (e.g. frontal pole, frontal gyrus) and sensorimotor network (e.g. central posterior gyrus) is a potential cause. The public needs to be vigilant: The ‘instant reward’ design of short videos may subtly change the brain’s decision-making patterns, leading to uncontrolled use.”

While the study provides new insights into the brain mechanisms that may underlie compulsive short-form video use, there are some limitations. The sample size was relatively small and consisted only of young adults enrolled in a university, limiting the ability to generalize the findings to other age groups or populations. The study also relied on a hypothetical gambling task, which may not fully capture the emotional and social dynamics involved in real-world short-video consumption. Future research could benefit from incorporating more ecologically valid tasks or using longitudinal designs to track how brain and behavior change over time with increased platform use.

In addition, the study’s design does not allow for causal conclusions. While the findings suggest a strong association between short-form video addiction symptoms, loss sensitivity, and brain activity patterns, they do not establish whether excessive platform use changes the brain, or whether people with certain cognitive styles or neural profiles are more prone to developing problematic usage patterns. Further research is needed to understand how these relationships unfold over time and whether targeted interventions—such as cognitive training or behavioral therapy—could help restore more balanced decision-making in affected individuals.

“In the future, we plan to: 1). explore the short-form video addiction risk prediction model based on brain imaging; 2). further explore the neural mechanism of short-form video addiction through longitudinal design; and 3). explore the psychological mechanism and molecular basis of short-form video addiction,” Wang explained. “The long-term goal is to integrate the multi-dimensional evidence of ‘brain imaging-psychological mechanism-molecular basis’ to reduce the risk of addiction from the source.”

The study, “Loss aversion and evidence accumulation in short-video addiction: A behavioral and neuroimaging investigation,” was authored by Chang Liu, Jinlian Wang, Hanbing Li, Qianyi Shangguan, Weipeng Jin, Wenwei Zhu, Pinchun Wang, Xuyi Chen, and Qiang Wang.