Evidence for Attention and focus in a connected world #

Every substantive claim on the Attention and focus in a connected world page is checked against current research. Here is each claim, how well today’s evidence supports it, and the sources. The full, de-duplicated source list lives on the references page.

Supported · strong evidence — Attention at the time of encoding is a prerequisite for forming durable memories; information that is not attended to is poorly remembered.

That attention and depth of processing at encoding strongly determine later memory is one of the most established findings in cognitive psychology (Craik & Lockhart’s levels-of-processing framework), and divided-attention-at-encoding studies reliably reduce later recall; this remains consensus in 2026.

Sources: Craik, F. I. M. & Lockhart, R. S. (1972), Levels of processing: A framework for memory research, Journal of Verbal Learning and Verbal Behavior, 11(6), 671-684 — https://doi.org/10.1016/S0022-5371(72)80001-X · full reference ›

Supported · moderate evidence — The mere presence of one’s own smartphone—silent and not in use—reduces available cognitive capacity (working memory and fluid reasoning), with the effect largest for people most dependent on their phones.

Ward et al. (2017) found a graded ‘brain drain’: performance was best with the phone in another room, worse on the desk, strongest for high phone-dependent users. The headline effect and its direction are widely cited, but some later replications report smaller or null effects, so the page frames it as a reliable nudge rather than a fixed law.

Sources: Ward, A. F., Duke, K., Gneezy, A. & Bos, M. W. (2017), Brain drain: The mere presence of one’s own smartphone reduces available cognitive capacity, Journal of the Association for Consumer Research, 2(2), 140-154 — https://doi.org/10.1086/691462 · full reference ›

Supported · moderate evidence — Putting the phone physically out of reach (e.g. in another room) protects attention better than relying on willpower to ignore a nearby phone.

The graded effect in Ward et al. (2017)—phone in another room outperformed phone on the desk—directly supports increasing physical distance over suppression; consistent with broader self-control research showing situation-modification beats in-the-moment resistance, though the precise size of the benefit varies.

Sources: Ward, A. F., Duke, K., Gneezy, A. & Bos, M. W. (2017), Brain drain: The mere presence of one’s own smartphone reduces available cognitive capacity — https://doi.org/10.1086/691462 · full reference ›

Supported · moderate evidence — Receiving a phone notification impairs performance on the task at hand even when the person does not view or respond to the notification.

Stothart, Mitchum & Yehnert (2015) showed that simply receiving a notification during a sustained-attention task increased errors (mind-wandering toward the phone), comparable to actively using it. The effect is replicated in spirit by the broader interruption literature, though it is a single primary study and effect sizes are modest.

Sources: Stothart, C., Mitchum, A. & Yehnert, C. (2015), The attentional cost of receiving a cell phone notification, Journal of Experimental Psychology: Human Perception and Performance, 41(4), 893-897 — https://doi.org/10.1037/xhp0000100 · full reference ›

Supported · strong evidence — Switching between tasks incurs a measurable performance cost, because reconfiguring mental set and carrying residue from the previous task takes time and resources.

Task-switching costs are among the most robust and replicated findings in cognitive psychology (Rubinstein, Meyer & Evans 2001; Monsell 2003), routinely shown as slower and less accurate responses after a switch; this is settled consensus in 2026.

Sources: Rubinstein, J. S., Meyer, D. E. & Evans, J. E. (2001), Executive control of cognitive processes in task switching, Journal of Experimental Psychology: Human Perception and Performance, 27(4), 763-797 — https://doi.org/10.1037/0096-1523.27.4.763 · full reference ›

Supported · moderate evidence — What people experience as ‘multitasking’ across information sources is largely rapid switching with attentional residue, not genuine simultaneous processing.

The view that apparent multitasking is serial task-switching (with reconfiguration and residue costs) rather than parallel processing is well supported for tasks competing for the same central/attentional resources; truly parallel performance is the exception, limited to highly automatic tasks.

Sources: Rubinstein, J. S., Meyer, D. E. & Evans, J. E. (2001), Executive control of cognitive processes in task switching — https://doi.org/10.1037/0096-1523.27.4.763 · full reference ›

Mixed · weak evidence — Heavy media multitasking causes a lasting decline in a person’s sustained attention.

Uncapher & Wagner (2018) report that heavier media multitaskers tend on average to perform worse on sustained-attention and working-memory tasks, but the literature is correlational and inconsistent, with some null findings; causal direction is unestablished. The page deliberately frames this as a correlated habit to avoid, not a proven cause—matching the evidence.

Sources: Uncapher, M. R. & Wagner, A. D. (2018), Minds and brains of media multitaskers: Current findings and future directions, PNAS, 115(40), 9889-9896 — https://doi.org/10.1073/pnas.1611612115 · full reference ›

Supported · moderate evidence — People who engage heavily in media multitasking tend, on average, to show poorer sustained attention and greater susceptibility to distraction.

As a descriptive association (not a causal claim), the link between heavier media multitasking and weaker performance on attention/working-memory measures is replicated in aggregate across the Uncapher & Wagner (2018) review, even though individual studies vary and the relationship is correlational.

Sources: Uncapher, M. R. & Wagner, A. D. (2018), Minds and brains of media multitaskers: Current findings and future directions — https://doi.org/10.1073/pnas.1611612115 · full reference ›

Supported · moderate evidence — Mindfulness meditation can improve attention, including sustained attention and the ability to return focus after distraction.

Meta-analytic evidence indicates mindfulness training produces small-to-moderate improvements in attentional measures, including sustained and executive attention. The direction is well supported, though effect sizes are modest and vary with practice type and dose, so the page presents it as helpful rather than transformative.

Sources: Sumantry, D. & Stewart, K. E. (2021), Meditation, mindfulness, and attention: A meta-analysis, Mindfulness, 12, 1332-1349 — https://doi.org/10.1007/s12671-021-01593-w · full reference ›

Supported · moderate evidence — Reducing external distractions in the study environment supports attention and concentration.

That removing interruptions and irrelevant sensory input improves on-task attention follows directly from interruption/notification studies (e.g. Stothart et al. 2015) and the wider distraction literature; the general principle is well established, with specific magnitudes depending on the distraction.

Sources: Stothart, C., Mitchum, A. & Yehnert, C. (2015), The attentional cost of receiving a cell phone notification — https://doi.org/10.1037/xhp0000100 · full reference ›