Your silenced phone probably isn’t draining your brain

You’re finishing a report with your phone face down beside the keyboard, silenced. You haven’t touched it in an hour. A widely shared 2017 study said even that costs you: the mere sight of your own phone, it reported, shrinks how much information your mind can hold and work with at once.

That finding spread through classrooms, offices and parenting advice. Then other researchers tried to repeat it. A carefully planned repeat found nothing, and the pooled evidence now runs from a small effect on one kind of memory to no effect at all.

The phone-and-attention story is a lesson in how a catchy result can outrun its checks. It isn’t the whole story, though. Some findings about phones hold up better than the famous one, and they point to cheaper, more practical fixes.

Two famous findings that shrank under replication

The silenced phone on the desk

In June 2017, the University of Texas at Austin announced a study led by Adrian Ward of its business school. Nearly 800 smartphone users took computer tests that demanded full concentration while their phones sat on the desk, in a pocket or bag, or in another room. The phones were silenced, and some were switched off.

People whose phones were in another room did significantly better than those with phones on the desk, and slightly better than those with phones in a pocket or bag. Turning the phone off or flipping it face down made no difference. Participants said they did not feel distracted. The study’s name for the effect, “brain drain,” stuck.

In 2022, Ana C. Ruiz Pardo and John Paul Minda at Western University in Ontario ran a preregistered direct replication of the study’s second experiment. Preregistered means they published their plan and predictions before collecting data, which keeps researchers from hunting for a result afterward. They used the same tasks and the same six conditions. They found no difference between phone locations on either test.

Three meta-analyses, which pool many studies into a single estimate, have since weighed in. They don’t agree on the headline:

• Böttger, poschik and zierer (2023), at the University of Augsburg, pooled 22 studies with 43 effects. They combined two kinds of research: studies of phone use and studies of mere presence. The overall effect was negative but small, a Hedges’ g of minus 0.14, or about a seventh of a standard deviation. Memory showed a significant drop; attention and general test performance did not. Only the studies from Asia showed a significant effect on their own, and the North American studies averaged close to zero. The authors still read the result as support: “The present meta-analysis essentially confirms the Brain Drain effect, which is negative regarding cognitive performance.”
• Douglas a. Parry (2024), in Media Psychology, pooled 56 studies covering 7,093 people and looked only at mere presence. Working memory capacity was the one function with a significant effect. Everything else came out null, and Parry flagged low statistical power across the field. His bottom line was limited support for an effect smaller than the original theory predicted.
• Andree Hartanto and colleagues (2024), at Singapore Management University, writing in Technology, Mind, and Behavior, pooled 166 effect sizes from 33 studies. They found no significant effect of a phone’s mere presence on cognitive outcomes, with an estimate very close to zero.

So the honest verdict depends on the claim. That a nearby phone slightly lowers scores on some working memory tasks, in some studies, is measured but below the threshold that matters for most daily life. That your phone on the desk lowers your IQ is not supported. None of these studies measured intelligence in any lasting sense. They measured performance on short lab tasks.

The heavy media multitasker

A similar arc followed a 2009 Stanford study in the Proceedings of the National Academy of Sciences. Eyal Ophir, Clifford Nass and Anthony D. Wagner reported that people who habitually juggle several media streams at once were more easily pulled off course by irrelevant information, and did worse on a test of switching between tasks.

In 2017, Wisnu Wiradhany and Mark R. Nieuwenstein at the University of Groningen ran two replications containing 14 tests. Only five showed a statistically significant effect in the predicted direction, and only two of those survived a stricter statistical check. Their meta-analysis of 39 effect sizes found a weak link that vanished after correcting for the habit of small studies to report bigger effects. They concluded the evidence gave them reason to doubt the association exists in lab tasks at all.

A 2018 review by Melina R. Uncapher and Wagner, one of the original authors, took a middle position. On balance, heavier multitaskers did worse in several areas, many studies found no difference, and the direction of cause remains undetermined. People who are already easily distracted may simply multitask more. What switching between tasks costs inside a workday is a different question, and the companion article on cognitive demands at work takes it up.

What holds up better: alerts you never answer

The phone’s mere presence may matter little. The phone making noise is another matter.

In a 2015 experiment at Florida State University, Cary Stothart, Ainsley Mitchum and Courtney Yehnert found that receiving notifications alone significantly disrupted performance on an attention-demanding task, even though participants never touched their phones. The disruption was comparable in size to effects seen when people actively use a phone for calls or texts. The authors proposed that the buzz prompts thoughts unrelated to the task, a form of mind-wandering.

A field test pointed the same way. In a study presented in 2016 at CHI, a major computing conference, Kostadin Kushlev, Jason Proulx and Elizabeth W. Dunn of the University of British Columbia had 221 undergraduates spend one week with alerts on and the phone kept within sight or reach, and another week with Do Not Disturb on and the phone out of sight. During the alerts week, students rated themselves higher on inattention and hyperactivity symptoms. The gap was small in absolute terms, about a tenth of a point on a four-point scale. The authors stressed that the results do not suggest phones cause ADHD, and they noted that the ratings were self-reported by students who knew which week was which.

Age may change the picture. In two experiments published in 2021, Wythe L. Whiting and Karla Klein Murdock of Washington and Lee University played notification sounds to three age groups. The effects on math accuracy and reaction time were most pronounced in adolescents, whose average age was 15, compared with young adults and people in midlife.

Not every alert-shaped cue registers. In 2024, researchers from Indonesia and the Netherlands showed people social media logos carrying red notification badges during a visual memory task. The badges hurt performance in one of three experiments, and the authors concluded that the logos did not interfere overall.

The verdict here is preliminary research. A handful of lab experiments and short field studies, mostly with students, suggest that sounds and vibrations pull at attention even when you ignore them. That is a modest evidence base. It points, though, to the cheapest fix in this article.

Paper still beats screens for some kinds of reading

Many people assume reading on a screen and reading on paper are equivalent, especially for anyone who grew up with tablets. A 2018 meta-analysis says otherwise, within limits.

Pablo Delgado, Cristina Vargas, Rakefet Ackerman and Ladislao Salmerón, writing in Educational Research Review, pooled 54 studies from 2000 to 2017 with roughly 171,000 participants. Comprehension was better on paper, with a small effect (a Hedges’ g of minus 0.21). Three details make the finding more useful than its headline:

• The paper advantage was larger when readers worked under a time limit than when they read at their own pace.
• It showed up for informational texts, such as reports and textbooks, but not for texts that were purely narrative.
• It grew over the years. Studies published more recently found a bigger paper advantage than older ones, which cuts against the idea that growing familiarity with screens would close the gap.

That adds up to positive evidence with a small effect. If you have to absorb a dense document against a deadline, paper may give you a slight edge. For purely narrative text, such as a novel, the pooled studies found no paper advantage. Study methods themselves, such as spacing and self-testing, belong to the library’s piece on how adults learn.

School phone rules are spreading faster than their evidence

Most schools already had rules

Phone bans sound new. Mostly, they aren’t. In the 2009-10 school year, 90.9% of US public schools said they prohibited the use of cell phones and text-messaging devices during school hours, according to the National Center for Education Statistics. That share fell to 65.8% by 2015-16. The survey then changed its question to ask about non-academic use of cell phones or smartphones, and 76.9% of schools reported that kind of ban in 2019-20.

The real gap was in high schools. In 2021-22, the Institute of Education Sciences reported, 76% of public schools prohibited non-academic phone use: 87% of elementary schools, 77% of middle schools and only 43% of high schools.

How many states, and how they count

What is new is state law. Florida acted first, in 2023, according to the Kansas Legislative Research Department. Education Week’s tracker, last updated October 26, 2026, counts at least 40 states plus the District of Columbia that require school districts to ban or restrict student phone use. The tally covers requirements only; states that merely recommend local bans or offer incentives for them are left out.

Other counts differ because they measure different things at different times. The Kansas researchers found 31 states plus DC that had acted to restrict or prohibit student devices as of the start of the 2025-26 school year. Most state laws carve out exceptions for students with individualized education programs or 504 plans, for medical needs and for emergencies.

Worldwide, UNESCO’s Global Education Monitoring team counted 60 education systems (30%) with bans in law or policy at the end of 2023, and 79 (40%) at the end of 2024. A March 2026 news report citing the team put the figure at 114 systems, about 58%.

What the two strongest studies found

The SMART Schools study, published in February 2025 in The Lancet Regional Health – Europe by Victoria A. Goodyear and colleagues at the University of Birmingham, compared 1,227 pupils aged 12 to 15 at 20 English secondary schools that restricted phones and 10 that permitted them.

Pupils at restrictive schools spent about 40 fewer minutes on their phones during the school day. Across whole weekdays and weekends, though, their phone time was no different. Neither was their teacher-rated attainment in English or math, their disruptive behavior in class, their sleep or their physical activity. Their mental wellbeing, the study’s main measure, didn’t differ either; teen wellbeing and social media get fuller treatment in our look at the Surgeon General’s advisory. The authors wrote that their findings “do not provide evidence to support the use of school policies that prohibit phone use during the school day in their current form…”

One finding cuts the other way. Across all 30 schools, pupils who spent more time on phones and social media had lower attainment and more disruptive classroom behavior. The study was a snapshot, not an experiment, only about one in ten invited schools took part, and phone time was self-reported.

The Florida study first appeared in October 2025 as a National Bureau of Economic Research working paper by David N. Figlio and Umut Özek. The bureau releases working papers in preliminary form, ahead of formal publication, so other economists can comment. The authors summarized the study in Education Next in May 2026. It followed one large urban district, among the 10 largest in the country, whose rule went further than the state’s: phones silenced and stored for the whole school day, lunch included. Using building-level location data, the researchers estimated that smartphone activity inside schools between 9 a.m. and 1 p.m. fell by about two-thirds. As summarized by the bureau in December 2025:

• Year one (2023-24): no statistically significant change in test scores. Suspensions rose 25% in September 2023 compared with a year earlier, and in-school suspensions for Black male students rose 30% at the schools most affected.
• Year two (2024-25): scores rose about 1.1 percentile points more in the schools where phone use had been heaviest than in those where it had been lightest, with gains concentrated in the spring. Discipline had returned to near pre-ban levels.
• Attendance: unexcused absences fell, and the researchers estimate that better attendance could explain as much as half of the score gain.

Taken together, the evidence that bans raise grades is insufficient. Bans reliably cut phone use during school hours. Their effect on learning was small where it was detected at all, and the first year brought more suspensions, including for Black male students.

“Digital dementia” gets the direction backward

“Digital dementia” is a popular label, not a diagnosis. The idea is that a lifetime of screens wears thinking down. The first generation to grow old with digital technology is now reaching the ages when dementia risk rises, which makes the idea testable.

In a 2025 meta-analysis in Nature Human Behaviour, Jared F. Benge of the University of Texas at Austin and Michael K. Scullin of Baylor University pooled 57 studies covering 411,430 adults over 50. Technology use was associated with less than half the odds of cognitive impairment (an odds ratio of 0.42) and a slower rate of cognitive decline (a hazard ratio of 0.74). The results held after accounting for demographic, socioeconomic and health factors, and held again when the analysis was limited to the highest-quality studies.

These were observational studies, so they cannot show that using a smartphone protects anyone’s brain. People who are healthier and sharper to begin with may simply use more technology. What the pooled data do show is that the evidence runs opposite to the slogan. Dementia risk in general is a topic the library’s dementia-risk coverage handles directly.

A notification plan graded by the evidence

This plan is built from the studies above. Each step carries the strength of the evidence behind it.

1. Silence sounds and vibrations during demanding work. Preliminary evidence: a lab experiment found that alerts disrupt attention even when ignored, and a week-long field study found more self-rated inattention when alerts were on. The cost is close to nothing. One caution from the field study’s authors: some people check more often when alerts are off, out of worry about missing something. If that describes you, fixed check-in times are a reasonable alternative, though nobody in these studies tested them.
2. Move the phone out of sight because it tempts you, not because it drains you. The evidence for a pure presence effect is weak: the original study found one, a direct replication did not, and pooled estimates run from small to zero. Another room still removes the easiest way to interrupt yourself.
3. Print dense, deadline-driven reading when you can. Positive evidence with a small effect, and only for informational text read under time pressure.
4. Take alert sounds seriously for teenagers doing homework. One study found notification sounds affected adolescents more than adults. A household rule about silencing alerts during homework rests on preliminary evidence, but it costs little to try.

When the trouble is not the phone

Turning off alerts won’t fix every attention problem. Some patterns deserve a clinician’s look rather than a new phone setting:

• Trouble with focus, organization or impulsivity in every part of life, for as long as you can remember. For teens and adults, the American Psychiatric Association’s ADHD guide sets two conditions: the symptoms date from before age 12, and they cause trouble in more than one area of life. Whether a lifelong pattern fits is for a clinician who can take a full history to decide. Adult ADHD is explored at length in the library’s article on attention and executive function.
• Concentration problems alongside low mood. Depression can show up as difficulty concentrating, remembering or making decisions, according to the National Institute of Mental Health. Its threshold is symptoms most of the day, nearly every day, for at least two weeks, with low mood or lost interest among them. If you are having thoughts of suicide, call or text 988 to reach the 988 Suicide & Crisis Lifeline. In a life-threatening emergency, call 911.

The one thing worth keeping

The phone sitting silently on your desk is a smaller problem than its reputation. The phone that buzzes has more evidence against it. Before your next stretch of demanding work, turn off the sounds and vibrations, and when the next headline announces what phones do to brains or what bans do for grades, ask one question first: has anyone repeated the study?

Sources

1. University of Texas at Austin. “The Mere Presence of Your Smartphone Reduces Brain Power, Study Shows (UT News, June 26, 2017).” news.utexas.edu
2. Acta Psychologica. “Ruiz Pardo AC, Minda JP. "Reexamining the 'brain drain' effect: A replication of Ward et al. (2017)." Acta Psychol (Amst), 2022. PubMed. DOI: 10.1016/j.actpsy.2022.103717.” pubmed.ncbi.nlm.nih.gov
3. Behavioral Sciences. “Böttger T, Poschik M, Zierer K. "Does the Brain Drain Effect Really Exist? A Meta-Analysis." Behav Sci (Basel), 2023. PubMed. DOI: 10.3390/bs13090751.” pubmed.ncbi.nlm.nih.gov
4. Media Psychology (Taylor & Francis), via Vrije Universiteit Amsterdam research portal. “Parry DA. "Does the Mere Presence of a Smartphone Impact Cognitive Performance? A Meta-Analysis of the 'Brain Drain Effect'." Media Psychology, 2024;27(5):737-762. DOI: 10.1080/15213269.2023.2286647.” research.vu.nl
5. Technology, Mind, and Behavior (American Psychological Association). “Hartanto A, Lua VYQ, Kasturiratna KTAS, et al. "The Effect of Mere Presence of Smartphone on Cognitive Functions: A Four-Level Meta-Analysis." Technology, Mind, and Behavior, 2024;5(1). DOI: 10.1037/tmb0000123.” doi.org
6. Journal of Experimental Psychology: Human Perception and Performance. “Stothart C, Mitchum A, Yehnert C. "The attentional cost of receiving a cell phone notification." J Exp Psychol Hum Percept Perform, 2015. PubMed. DOI: 10.1037/xhp0000100.” pubmed.ncbi.nlm.nih.gov
7. Association for Computing Machinery (Proceedings of the 2016 CHI Conference on Human Factors in Computing Systems). “Kushlev K, Proulx J, Dunn EW. "'Silence Your Phones': Smartphone Notifications Increase Inattention and Hyperactivity Symptoms." CHI 2016, San Jose, CA, pp. 1011-1020. DOI: 10.1145/2858036.2858359.” doi.org
8. Quarterly Journal of Experimental Psychology. “Whiting WL, Murdock KK. "Notification alert! Effects of auditory text alerts on attention and heart rate variability across three developmental periods." Q J Exp Psychol, 2021. PubMed. DOI: 10.1177/17470218211041851.” pubmed.ncbi.nlm.nih.gov
9. Experimental Psychology. “Wiradhany W, Pócs A, Baumgartner SE. "Are Social Media Notifications Distracting?" Exp Psychol, 2024. PubMed. DOI: 10.1027/1618-3169/a000625.” pubmed.ncbi.nlm.nih.gov
10. Proceedings of the National Academy of Sciences. “Ophir E, Nass C, Wagner AD. "Cognitive control in media multitaskers." Proc Natl Acad Sci U S A, 2009. PubMed. DOI: 10.1073/pnas.0903620106.” pubmed.ncbi.nlm.nih.gov
11. Attention, Perception & Psychophysics. “Wiradhany W, Nieuwenstein MR. "Cognitive control in media multitaskers: Two replication studies and a meta-Analysis." Atten Percept Psychophys, 2017. PubMed. DOI: 10.3758/s13414-017-1408-4.” pubmed.ncbi.nlm.nih.gov
12. Proceedings of the National Academy of Sciences. “Uncapher MR, Wagner AD. "Minds and brains of media multitaskers: Current findings and future directions." Proc Natl Acad Sci U S A, 2018. PubMed. DOI: 10.1073/pnas.1611612115.” pubmed.ncbi.nlm.nih.gov
13. Educational Research Review (Elsevier), via University of Haifa research portal. “Delgado P, Vargas C, Ackerman R, Salmerón L. "Don't throw away your printed books: A meta-analysis on the effects of reading media on reading comprehension." Educational Research Review, 2018;25:23-38. DOI: 10.1016/j.edurev.2018.09.003.” cris.haifa.ac.il
14. National Center for Education Statistics. “Digest of Education Statistics, Table 233.50: Percentage of public schools with various safety and security measures, 1999-2000 through 2019-20.” nces.ed.gov
15. Institute of Education Sciences. “New Schools Data Examine Violent Incidents, Bullying, Drug Possession, 'Restorative' Practices, Security Staff, and More (press release, January 17, 2024).” ies.ed.gov
16. Kansas Legislative Research Department. “Briefing Book 2026: Cellphone Policies in K-12 Schools (March 2, 2026).” klrd.gov
17. Education Week. “Which States Ban or Restrict Cellphones in Schools? (updated October 26, 2026).” edweek.org
18. UNESCO Global Education Monitoring Report, World Education Blog. “To ban or not to ban? Monitoring countries' regulations on smartphone use in school (updated September 23, 2025).” world-education-blog.org
19. Business Today. “Not just distraction: 114 countries now restrict phones in schools (March 22, 2026).” businesstoday.in
20. The Lancet Regional Health – Europe. “Goodyear VA, Randhawa A, Adab P, et al. "School phone policies and their association with mental wellbeing, phone use, and social media use (SMART Schools): a cross-sectional observational study." Lancet Reg Health Eur, 2025. PubMed. DOI: 10.1016/j.lanepe.2025.101211.” pubmed.ncbi.nlm.nih.gov
21. National Bureau of Economic Research. “Figlio DN, Özek U. "The Impact of Cellphone Bans in Schools on Student Outcomes: Evidence from Florida." NBER Working Paper 34388, October 2025. DOI: 10.3386/w34388.” nber.org
22. National Bureau of Economic Research. “School Cell Phone Bans and Student Achievement (NBER Digest, December 1, 2025).” nber.org
23. Education Next. “Figlio DN, Özek U. "Can Banning Cellphones Save Student Learning? Evidence from Florida, home of the first statewide mandate." Education Next, Vol. 26, No. 2 (May 12, 2026).” educationnext.org
24. National Bureau of Economic Research. “NBER Help: Working Papers – General Information.” nber.org
25. Nature Human Behaviour. “Benge JF, Scullin MK. "A meta-analysis of technology use and cognitive aging." Nat Hum Behav, 2025. PubMed. DOI: 10.1038/s41562-025-02159-9.” pubmed.ncbi.nlm.nih.gov
26. American Psychiatric Association. “What is ADHD? (reviewed October 2025).” psychiatry.org
27. National Institute of Mental Health. “Depression (NIH Publication No. 24-MH-8079, revised 2024).” nimh.nih.gov