“Cerebral Rot” or What the Abuse of Trash Content on the Internet Can Do to the Mind“

Addiction to social media reduces gray matter, shortens attention span, weakens memory, and distorts cognitive processes

Recent research has found that the use and abuse of the internet is associated with a decrease in gray matter in the prefrontal regions of the brain.

Cerebral Rot: “Deterioration of a person’s mental or intellectual state as a result of the excessive consumption of material (particularly online content) considered trivial or not challenging.” This definition was provided by the Oxford Dictionary, which, after the votes of more than 37,000 people, chose this concept as its word of the year. The dictionary’s experts noted that the term has recently gained relevance “to express concerns about the impact of excessive consumption of low-quality content on social media,” the publication says. The frequency of use of the term increased by 230% between 2023 and 2024.

Cerebral rot is not merely a linguistic whim. Over the past 10 years, science has been able to demonstrate that excessive consumption of trash content on the internet—sensationalism, conspiracy, emptiness—is altering our brains, to the point that the word “rotten” may not be so exaggerated. Evidence shows that social media is reducing gray matter, shortening attention spans, weakening memory, and distorting fundamental cognitive processes, according to the British newspaper The Guardian, which cites numerous academic studies from institutions such as Harvard Medical School, the University of Oxford, and King’s College London.

Infinite scrolling on social media increases boredom

One such study, published last year, showed that internet addiction causes structural changes in the brain, which directly affect an individual’s behavior and capabilities. Michoel Moshel, a researcher at the School of Psychological Sciences at Macquarie University (Australia) and co-author of the study, explains that the compulsive consumption of content on social media—known as doomscrolling—“exploits our brain’s natural tendency to seek novelty, especially when it comes to potentially harmful or alarming information, a trait that once helped us survive.”

Moshel points out that, with features like infinite scrolling designed to keep you glued to your mobile device, people—especially young ones—can become trapped in a cycle of content consumption for hours. “This can severely affect attention and executive functions by overwhelming our focus and altering the way we perceive and react to the world,” the researcher states.

Eduardo Fernández Jiménez, a clinical psychologist at Hospital La Paz in Madrid, explains that the brain activates different neural networks to configure various types of attention. He adds that the problematic use of mobile phones and the internet is causing issues with what is known as sustained attention: “It allows you to concentrate on the same task for a relatively long period. It is linked to academic learning processes,” he says. The problem, he notes, is that social media users are usually exposed to very changing, variable stimuli (an Instagram notification, a WhatsApp message, a news alert) with addictive potential. This causes the focus of attention to constantly jump from one place to another, affecting its own capacity.

The first warning came with email:

Some experts have been warning about this issue almost since the beginning of the century, when email became a commonly used tool. In 2005, The Guardian headlined: “Emails ‘are a threat to IQ’.” The story recounted that a team of scientists from the University of London wondered what impact the incessant bombardment of information might have on the brain. After 80 clinical trials, they found that the IQ of participants who used email and mobile phones daily dropped by an average of 10 points. The researchers measured that this constant demand for attention had more negative effects than cannabis consumption.

This was before the advent of tweets, Instagram reels, TikTok challenges, and instant notifications. The current scenario is even less encouraging. Recent studies have found that the use and abuse of the internet is associated with a decrease in gray matter in the prefrontal regions of the brain—the area involved in problem-solving, emotional regulation, memory, and impulse control.

Moshel and his colleagues’ work follows this line. Their latest study reviewed 27 neuroimaging studies and found that excessive internet consumption is related to a reduction in gray matter volume in brain regions involved in reward processing, impulse control, and decision-making. “These changes reflect patterns observed in substance addictions,” asserts the scientist, comparing them to those seen with methamphetamines and alcohol.

That’s not all. The research also found that “these neuroanatomical changes in adolescents coincide with the disruption of processes such as identity formation and social cognition, which are critical during this developmental stage.” It works almost like a loop, where the most vulnerable can be the most affected. According to the results of a study published in Nature in November, people with poorer mental health are more likely to browse trash content, which further exacerbates their symptoms.

In December, psychologist Carlos Losada offered EL PAÍS some recommendations to avoid falling into doomscrolling—in other words, to avoid being sucked into the black hole of junk content reinforced by algorithms: acknowledging the problem, making an effort to disconnect, and engaging in activities that require physical presence, such as meeting friends or playing sports, are some of his suggestions.

Moshel says: “These activities are fundamental for brain health and overall well-being, helping to balance the potentially harmful effects of prolonged screen use.” He emphasizes that the type of content consumed is a key factor in moderating anatomical changes in the brain. “Focus on both the quality and quantity of screen time. Prioritize educational content that avoids addictive features. Set clear, age-appropriate limits on daily screen use and encourage regular breaks,” he adds.

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