One hard focus block

Do this

• Block 90–120 minutes for one mentally demanding task: learning, writing, solving.
• Put your phone in a different room. Face down on the desk is not enough.
• Narrow what you can see: one window on screen, a clear desk, a cap or hood if it helps.
• Pick work hard enough that you get it wrong about 15% of the time. The friction is the sign that learning is happening.
• Stop when the block ends and return to the material a day or two later.
• A week later, test yourself from memory instead of re-reading. Asking an AI model to quiz you works well.

Why it works

The adult brain changes when you make real attempts and miss. Those errors, together with alertness, trigger the rewiring. A phone within reach takes up attention even when it stays silent. He ties the habit of pushing through resistance to a brain region called the anterior mid-cingulate cortex, which is more active in people who regularly do hard things.

What the research says

Self-testing is one of the best-supported findings in learning research. The phone and 15% figures each rest on one well-known paper: the phone effect has shrunk in later replications, and the 15% error rate comes from a mathematical model checked against animal data.

• Roediger & Karpicke, Psychological Science, 2006Test-enhanced learning: taking memory tests improves long-term retentionStudents who read a passage and then took a recall test remembered more a week later than students who re-read it.
• Ward et al., Journal of the Association for Consumer Research, 2017Brain Drain: The Mere Presence of One's Own Smartphone Reduces Available Cognitive CapacityPeople did worse on attention and reasoning tasks with their phone on the desk than with it in another room, even switched off.
• Wilson et al., Nature Communications, 2019The Eighty Five Percent Rule for optimal learningFor a broad class of learning models, training is fastest at an error rate of about 15.87%.
• Touroutoglou et al., Cortex, 2020The tenacious brain: How the anterior mid-cingulate contributes to achieving goalsReviews the evidence that this region supports persistence when effort is costly.
• Parvizi et al., Neuron, 2013The will to persevere induced by electrical stimulation of the human cingulate gyrusStimulating this area in two patients produced the sense of an approaching challenge and the resolve to push through it.

Watch out

If your day doesn't allow one long block, two shorter ones still count.