THE TAKEAWAY: Brain fatigue from screen time isn't just eye strain; it is the physiological cost of your prefrontal cortex repeatedly reloading working memory states.
Every time you switch from a document to a text or notification, your brain leaves behind "attention residue." The prefrontal cortex must suppress the previous context and activate a new neural network, consuming glucose and metabolic bandwidth. Batching communication into scheduled windows preserves executive function and reduces mental burnout.
