You sit down to do important work. Within minutes, a notification flashes. You glance at it. Before you know it, eleven minutes have passed, you have checked three websites, responded to a message that could have waited, and now you are trying to remember where you were. This is not a personal failing or a generational weakness. It is the predictable outcome of an environment engineered to fracture attention, combined with a nervous system that evolved to respond to novelty and social cues. The problem is structural. The solution, to the extent there is one, is also structural.
What neuroscience has uncovered over the last two decades is both discouraging and clarifying. The discouraging part: the conditions under which most modern knowledge workers operate are nearly optimal for preventing sustained attention. The clarifying part: the specific factors that degrade focus are well understood, which means they can, with effort and design, be addressed systematically. Focus is not a fixed trait distributed unevenly among the disciplined and the scattered. It is a capacity that responds to environment, sleep, exercise, practice, and the deliberate removal of interruption. This article draws on the research to explain what actually helps and what does not.
The stakes are not trivial. The ability to focus deeply on cognitively demanding work is increasingly the skill that separates those who produce exceptional results from those who merely stay busy. As automation handles routine tasks, the premium accrues to people who can think complexly, synthesize information, write with clarity, and solve novel problems -- all of which require sustained attention. Learning how to improve focus is not a productivity trick. It is one of the more consequential investments available to a knowledge worker.
"What information consumes is rather obvious: it consumes the attention of its recipients. Hence a wealth of information creates a poverty of attention." -- Herbert Simon, 1971
Key Definitions
Sustained attention: The ability to maintain directed focus on a single task or stimulus over a prolonged period, typically operationalized in research as performance stability over 10 to 45 minutes on a continuous performance task.
Attention residue: A concept from researcher Sophie Leroy describing the phenomenon in which, after switching away from a task (voluntarily or through interruption), part of one's cognitive resources remains allocated to the prior task, degrading performance on the new one.
Flow state: A term coined by Mihaly Csikszentmihalyi to describe the subjective experience of complete absorption in a task, characterized by effortless concentration, distorted time perception, intrinsic motivation, and the merging of action and awareness.
Directed attention fatigue: The depletion of the effortful, voluntary attention capacity used for focused work, as distinguished from involuntary attention (which requires no effort). Described within Attention Restoration Theory by Rachel and Stephen Kaplan.
Supertasker: A term used by David Strayer (2006) to describe the small fraction of the population (approximately 2.5%) who can perform two cognitively demanding tasks simultaneously without measurable performance degradation. The vast majority of people who believe they multitask effectively are not supertaskers.
The Interruption Problem: What Gloria Mark Found
The 23-Minute Finding
The most cited number in conversations about workplace focus comes from Gloria Mark at UC Irvine. In studies using direct observation of knowledge workers in naturalistic office settings, Mark and colleagues found that after an interruption, workers took an average of 23 minutes and 15 seconds to fully return to the original task. This figure was published across multiple studies through the mid-2000s and 2010s, and subsequent work has broadly confirmed the general magnitude of the refocus cost, even if the exact number varies by task type and interruption severity.
What made Mark's findings particularly important was what she discovered about the source of interruptions. The conventional assumption was that external interruptions (a colleague stopping by, a phone call, an incoming notification) were the primary culprit. Mark's observation data showed that workers frequently interrupted themselves: they would be working on a document and then, unprompted, switch to email or a messaging app. Self-interruption accounted for a substantial portion of task fragmentation. This matters because it shifts the intervention target. If interruptions were purely external, the solution would be about managing other people. Since they are partly self-generated, the solution requires understanding and reshaping personal habit.
What Happens During a Refocus Period
The cost of an interruption is not simply the time spent on the interrupting task. The mechanism, as described by Sophie Leroy (2009) in her attention residue research, is cognitive. When you shift from Task A to Task B without completing Task A, your cognitive system continues allocating resources to Task A: it keeps the unfinished goals, the partially loaded context, and the relevant information in a background processing state. This residue occupies working memory and inhibits performance on Task B. The more pressing or complex Task A was, the more residue it leaves. Even after you physically return to Task A after an interruption, the residue from whatever interrupted you now occupies partial attention. Refocusing is not a simple on/off switch but a gradual recapture of cognitive context.
Multitasking: The Supertasker Illusion
Strayer's Research on Who Can Actually Multitask
David Strayer at the University of Utah conducted research in 2006 that directly tested people's ability to perform two demanding cognitive tasks simultaneously -- specifically, driving while talking on a hands-free mobile phone. Using driving simulators that could objectively measure reaction times, brake performance, and following distance, Strayer found that performance degraded substantially under dual-task conditions for the overwhelming majority of participants. The degree of impairment was comparable to driving with a blood alcohol level at the legal limit in many jurisdictions.
Among roughly 200 participants, only about 2.5% showed no measurable performance degradation under dual-task conditions. Strayer called these rare individuals supertaskers. Subsequent work confirmed that supertaskers are not simply better at both tasks individually -- they appear to have an unusual capacity to actually process two demanding task streams in parallel, rather than switching between them rapidly. Crucially, the majority of people who reported confidence in their own ability to multitask without degradation were not supertaskers. Perceived multitasking ability bore essentially no relationship to actual multitasking ability. People who multitask most frequently tend to perform worst on laboratory multitasking measures, suggesting that heavy multitasking may reflect poor attentional control rather than strong attentional capacity.
The Phone on Your Desk: Ward et al. (2017)
Brain Drain Through Mere Presence
Adrian Ward and colleagues at the University of Texas at Austin published a 2017 study titled "Brain Drain: The Mere Presence of One's Own Smartphone Reduces Available Cognitive Capacity." In two experiments, participants performed cognitive capacity tests (Working Memory Capacity and Fluid Intelligence) under one of three conditions: phone on desk face-down, phone in pocket or bag, or phone in another room.
The results were striking. Participants in the phone-on-desk condition performed significantly worse than those in the other-room condition, even though all participants were instructed not to use their phones. The in-pocket/bag condition fell between the two. The effect was most pronounced for participants who reported the highest smartphone dependence: the more a person relied on their phone, the greater the cognitive cost of having it present and visible.
Ward's interpretation was that the brain automatically allocates attentional resources toward resisting the impulse to check the phone, and these resources are therefore not available for the task at hand. The effort of not picking up the phone is itself cognitively costly. The practical implication is blunt: removing the phone from the room is not an indulgence. It is a meaningful environmental intervention with measurable cognitive benefits.
Flow State and the Architecture of Deep Attention
Csikszentmihalyi's Framework
Mihaly Csikszentmihalyi at the University of Chicago spent decades studying flow, beginning in the 1970s with studies of rock climbers, chess players, and surgeons, and expanding to broader populations using the Experience Sampling Method (ESM), in which participants were randomly paged throughout the day and asked to report their current activity, mood, and cognitive state. By the time of his 1990 book Flow: The Psychology of Optimal Experience, Csikszentmihalyi had collected data from over 8,000 participants across multiple cultures.
The consistent finding was that people reported their highest levels of concentration, engagement, creativity, and satisfaction during flow -- not during leisure or relaxation. Flow occurred most reliably under specific conditions: clear goals, immediate feedback on progress, and a balance between the challenge of the task and the person's current skill level. Too easy, and attention drifts through boredom. Too hard, and anxiety prevents engagement. The narrow channel of matched challenge and skill is where sustained focus most naturally arises.
For practical focus improvement, Csikszentmihalyi's framework suggests a specific design principle: calibrate task difficulty to your current ability. Working at or slightly beyond your edge keeps the challenge-skill balance in the flow zone. Working on tasks far below your capacity produces wandering attention that no amount of willpower will reliably correct.
Cal Newport and the Deep Work Extension
Cal Newport, a computer science professor at Georgetown University, built on Csikszentmihalyi's flow research in his 2016 book Deep Work. Newport argued that the capacity for sustained focus on cognitively demanding work is not only the precondition for flow but the primary differentiator of valuable knowledge work output. He proposed that most professionals have allowed their focused work capacity to atrophy through constant connectivity, and that rebuilding it requires deliberate environmental and scheduling interventions rather than simply trying harder to concentrate.
Newport's contribution was largely practical: the importance of deep work scheduling, environmental design, shutdown rituals, and treating concentration as a trainable skill with capacity that builds progressively. His framework aligns closely with the neurological evidence about how sustained attention operates and degrades.
The Pomodoro Technique: Timed Focus Blocks
How It Works and Why It Helps
The Pomodoro Technique, developed by Francesco Cirillo in the late 1980s as a university student using a tomato-shaped kitchen timer (pomodoro is Italian for tomato), divides work into 25-minute focused intervals separated by 5-minute breaks. After four consecutive intervals, a longer break of 15 to 30 minutes is taken.
The technique works for several reasons grounded in attention research. It sets a bounded, manageable focus target: most people can commit to 25 minutes of focused work even when motivation is low, whereas an open-ended work session feels more daunting. The time pressure activates a mild urgency that helps exclude distracting thoughts. The scheduled breaks remove the anxiety about when you will get to check your phone or email, because there is always an answer: in 25 minutes. This reduces the self-interruption that Mark's research identified as a major driver of task fragmentation.
The Pomodoro Technique is not universally optimal. For work requiring extended context loading -- complex writing, deep analysis, programming at the architectural level -- a 25-minute block may be too short to enter a productive state before the break interrupts momentum. For these tasks, longer blocks of 45 to 90 minutes with scheduled breaks afterward may better match the natural rhythm of sustained attention. The underlying principle (bounded focus intervals with deliberate breaks) is more important than the specific duration. The dedicated article on the Pomodoro Technique covers implementation in detail.
Sleep, BDNF, and the Neuroscience of Attention
Why Sleep Is the Foundation
The prefrontal cortex, the region of the brain most responsible for sustained attention, working memory, and executive control, is disproportionately sensitive to sleep deprivation. Matthew Walker at UC Berkeley and others have documented that even modest sleep restriction -- six hours per night over two weeks -- produces cumulative cognitive deficits equivalent to two full nights of total sleep deprivation. The insidious aspect is that sleep-deprived individuals do not accurately perceive their own impairment: their subjective assessments of alertness stabilize while their objective performance continues to decline.
Sleep also serves a critical consolidation function for attention capacity itself. Brain-Derived Neurotrophic Factor (BDNF), a protein that promotes the growth and maintenance of neurons and synaptic connections, is released during slow-wave sleep. BDNF is essential for the plasticity that underlies learning, memory, and the neurological infrastructure of sustained attention. Chronic sleep restriction reduces BDNF levels, gradually degrading the neural basis for focus. The evening practices that protect sleep quality are explored in how to wind down in the evening.
Exercise as a Focus Amplifier
Regular aerobic exercise is one of the most reliably documented non-pharmacological interventions for attention capacity. It increases cerebral blood flow, stimulates BDNF production, and promotes the structural development of the prefrontal cortex and hippocampus. Studies have found that even a single bout of moderate aerobic exercise (20 to 30 minutes of brisk walking or cycling) produces measurable improvements in sustained attention and executive function that persist for several hours. Longitudinal studies have found that physically active individuals show greater prefrontal cortex volume and better performance on cognitive control tasks than sedentary individuals of comparable age.
Timing matters for maximizing the attention benefit: exercise in the morning elevates BDNF and catecholamine levels during the hours most people use for cognitively demanding work. This does not mean evening exercise is without value -- it still produces significant benefits -- but morning exercise appears to prime the brain specifically for the focused work that follows. The question of when to exercise fits naturally into what makes a good morning routine.
Attention Restoration Theory: Why Nature Breaks Work
The Kaplan Framework
Rachel and Stephen Kaplan developed Attention Restoration Theory (ART) at the University of Michigan in the 1980s and 1990s. Their central distinction was between directed attention (the effortful, voluntary focus required for complex tasks) and involuntary attention (the automatic, effortless attention drawn by inherently interesting stimuli). Directed attention fatigues with use and requires recovery. Natural environments, they proposed, are particularly restorative because they engage involuntary attention through soft fascination -- the movement of water, the patterns of trees, the behavior of animals -- without demanding the effortful cognitive engagement that depletes directed attention.
Empirical support for ART has come from multiple directions. Studies by Marc Berman and colleagues (2008) found that a 50-minute walk in a natural setting improved performance on a working memory and attention test by approximately 20%, while a 50-minute walk in an urban setting produced no improvement. Experiments by Roger Ulrich showed that hospital patients with window views of trees recovered faster and required less pain medication than those viewing brick walls. Even brief exposures to natural settings or images of natural environments have produced measurable attention restoration effects in laboratory studies.
The practical implication for focus improvement is specific: breaks that involve passive indoor screen use (scrolling social media, watching videos) do not restore directed attention because they continue engaging the brain in social and narrative processing. Breaks that involve outdoor exposure, gentle walking, or even viewing nature images allow directed attention to recover.
ADHD vs. Normal Attention Difficulties
Understanding the Spectrum
Attention difficulties exist on a spectrum. Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental condition affecting approximately 5 to 7% of children and 2 to 5% of adults, characterized by persistent inattention, hyperactivity, and impulsivity that impairs functioning across multiple domains. ADHD involves underlying differences in prefrontal cortex development, dopamine and norepinephrine signaling, and default mode network regulation.
The environmental and lifestyle strategies that improve focus in neurotypical individuals (structured focus blocks, phone removal, adequate sleep, exercise, nature breaks) are also beneficial for individuals with ADHD, but they are typically insufficient as standalone interventions for clinically significant ADHD. Medication, cognitive-behavioral therapy, and environmental accommodations are evidence-based components of ADHD management that address the underlying neurological differences.
The important practical point is that struggling to focus does not indicate ADHD. The conditions of modern knowledge work -- constant notifications, open offices, fragmented schedules, always-on communication norms -- are genuinely hostile to human attention. Many people experience significant focus difficulties that are environmental rather than clinical in origin, and these respond well to environmental redesign. If focus difficulties persist despite structured environmental interventions and adequate sleep and exercise, consultation with a clinician is warranted.
Practical Takeaways
Design the environment before the session. Phone in another room, notifications off, door closed or headphones on. Make the decision before sitting down, not after the urge to check arises.
Use timed focus blocks. Start with 25-minute Pomodoro intervals if concentration capacity is low; extend to 45 to 90-minute blocks as capacity builds. Schedule breaks rather than taking them reactively.
Protect sleep above all else. No focus strategy compensates for chronic sleep restriction. Seven to nine hours is not a luxury; it is the physiological precondition for the attention the other strategies depend on.
Take movement breaks outdoors when possible. A 10- to 20-minute walk in a natural or semi-natural environment produces measurable attention restoration. Screen-based breaks do not.
Schedule important focused work during peak alertness. Identify your natural energy peaks (likely morning for most people but afternoon for late chronotypes) and protect those hours for cognitively demanding work.
Exercise in the morning. If logistically possible, morning aerobic exercise primes BDNF and prefrontal function for the hours that follow.
Reduce decision load around focus sessions. Decision fatigue degrades focus capacity. Pre-planning what you will work on, and standardizing recurring decisions, preserves cognitive resources for the work itself.
Accept the 15-minute warm-up. It takes time to load context and approach anything resembling flow. Do not evaluate the quality of a focus session in its first 15 minutes. Commit to the full block before assessing.
References
- Mark, G., Gudith, D., and Klocke, U. "The Cost of Interrupted Work: More Speed and Stress." CHI '08 Proceedings, 2008.
- Leroy, S. "Why Is It So Hard to Do My Work? The Challenge of Attention Residue When Switching Between Work Tasks." Organizational Behavior and Human Decision Processes, 2009.
- Strayer, D., and Watson, J. M. "Supertaskers: Profiles in Extraordinary Multitasking Ability." Psychonomic Bulletin and Review, 2010.
- Ward, A. F., Duke, K., Gneezy, A., and Bos, M. W. "Brain Drain: The Mere Presence of One's Own Smartphone Reduces Available Cognitive Capacity." Journal of the Association for Consumer Research, 2017.
- Csikszentmihalyi, M. Flow: The Psychology of Optimal Experience. Harper and Row, 1990.
- Newport, C. Deep Work: Rules for Focused Success in a Distracted World. Grand Central Publishing, 2016.
- Walker, M. Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner, 2017.
- Berman, M. G., Jonides, J., and Kaplan, S. "The Cognitive Benefits of Interacting With Nature." Psychological Science, 2008.
- Kaplan, S. "The Restorative Benefits of Nature: Toward an Integrative Framework." Journal of Environmental Psychology, 1995.
- Ratey, J. J. Spark: The Revolutionary New Science of Exercise and the Brain. Little, Brown, 2008.
- Cirillo, F. The Pomodoro Technique. FC Garage, 2006.
- van Dongen, H. P. A., Maislin, G., Mullington, J. M., and Dinges, D. F. "The Cumulative Cost of Additional Wakefulness." Sleep, 2003.
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Frequently Asked Questions
How long does it take to regain focus after an interruption?
Research by Gloria Mark at UC Irvine found that after an interruption, knowledge workers take an average of 23 minutes and 15 seconds to fully return to the task they were working on. This figure comes from direct observation of workers in naturalistic office settings. Interestingly, the interruptions were not always external: workers frequently interrupted themselves by switching to email or messaging apps. The practical implication is that even a brief disruption carries a significant refocus cost, which is why protecting focus blocks matters more than trying to 'power through' a noisy environment.
What is the multitasking myth in focus research?
Most people believe they can multitask effectively, but research by David Strayer at the University of Utah (2006) showed that only about 2.5% of the population are true 'supertaskers' capable of performing two demanding tasks simultaneously without degradation. For the other 97.5%, what feels like multitasking is actually rapid task-switching, which incurs attention residue: the mental load of the previous task lingers and degrades performance on the current one. Strayer's work, combined with Sophie Leroy's attention residue research, suggests that serial focus on single tasks outperforms attempted multitasking for almost everyone.
Does having your phone on your desk hurt focus even if you do not use it?
Yes. A 2017 study by Adrian Ward and colleagues at the University of Texas at Austin found that the mere presence of a smartphone on a desk reduced cognitive capacity, even when participants were told to turn it off and place it face-down. The effect was proportional to how dependent participants were on their phones: heavier users showed greater cognitive impairment simply from the phone being visible. The brain appears to allocate resources toward resisting the urge to check the device, leaving less capacity for the task at hand. Moving the phone to another room eliminated the effect entirely.
What is flow state and how does it relate to focus?
Flow, described by Mihaly Csikszentmihalyi based on decades of research with thousands of participants, is a state of complete absorption in a challenging task where time distorts and effort feels effortless. It requires a balance between task difficulty and current skill level: too easy produces boredom, too hard produces anxiety. Flow is relevant to focus because it represents the high end of sustained attention, and the conditions that produce it (clear goals, minimal interruption, matched challenge) are also the conditions that sustain deep focus more generally. Most people take 15 to 20 minutes of uninterrupted engagement to enter anything resembling flow.
How does sleep affect the ability to focus?
Sleep deprivation directly impairs the prefrontal cortex, the brain region most responsible for sustained attention, working memory, and inhibitory control. Even moderate sleep restriction (six hours per night for two weeks) produces cognitive deficits equivalent to two full nights of sleep deprivation, yet most people in restricted conditions do not perceive themselves as impaired. Sleep also promotes the release of BDNF (brain-derived neurotrophic factor), a protein essential for neuroplasticity and learning consolidation. Without adequate sleep, the neural architecture that supports focused work degrades. Seven to nine hours remains the evidence-based recommendation for most adults.
Does exercise improve focus?
Yes. Aerobic exercise increases blood flow to the prefrontal cortex and stimulates the release of BDNF, which supports the growth and maintenance of neurons involved in attention and working memory. Studies have shown that even a single session of moderate aerobic exercise (20 to 30 minutes) produces measurable improvements in sustained attention that last several hours. Regular exercise has longer-term structural effects: physically active individuals show greater prefrontal cortex volume and better performance on attention tasks than sedentary individuals. Timing matters: morning exercise appears to prime the brain for focused work throughout the day.
What is attention restoration theory and can nature help focus?
Attention Restoration Theory, developed by Rachel and Stephen Kaplan in the 1980s and 1990s, proposes that directed attention (the kind used for focused work) is a finite resource that depletes with use. Natural environments restore this capacity because they engage 'involuntary attention,' a softer mode of attention drawn by natural stimuli (trees, water, clouds) that does not require effortful direction. Research in this tradition has shown that exposure to natural settings, even briefly, reduces mental fatigue and improves performance on attention tasks. A 20-minute walk in a park produces measurably better attention restoration than a 20-minute walk on a busy urban street.