Brain scans show that simultaneously using smartphones, laptops, and tablets (all while watching TV, probably) may change the structure of your brain. Media multitaskers have lower gray-matter density in certain brain regions compared to people who just use one device occasionally, according to a study published in PLoS One this week.

Previous studies have found connections between high media-multitasking activity and poor attention in the face of distraction, along with depression and anxiety. Now, Kep Kee Loh and Ryota Kanai from University College London wanted to see how “concurrent consumption” of multiple media forms affects neural processes.

The duo recruited 75 adults, about 25 years old on average, to answer a questionnaire about their use of 10 different media types: print media, television, computer-based video, music, voice calls using mobile or telephone, instant messaging, text messaging, e-mail, web surfing, and other computer-based applications. Then they scanned the brains of 40 of the participants using functional magnetic resonance imaging (fMRI), which measures brain activity based on blood flow.

They found that people who used a higher number of media devices at the same time also had smaller gray-matter density in the anterior cingulate cortex (ACC, highlighted below), a region of the brain that’s responsible for cognitive and emotional control functions.

“Media multitasking is becoming more prevalent in our lives today and there is increasing concern about its impacts on our cognition and social-emotional well-being,” Loh says in a news release. “Our study was the first to reveal links between media multitasking and brain structure.”

The researchers haven’t nailed down the mechanisms underlying these changes, and while the new study supports earlier findings, it’s still just a link. “Although it is conceivable that individuals with small ACC are more susceptible to multitasking situations due to weaker ability in cognitive control or socio-emotional regulation,” Loh adds, “it is equally plausible that higher levels of exposure to multitasking situations leads to structural changes in the ACC.” A long-term study is needed to unambiguously determine the direction of causation.

Images: Blake Patterson via Flickr CC BY 2.0 (top, cropped), 2014 Loh, Kanai, PLoS ONE (middle)