“Neurologically speaking, though, there are reasons we develop a confused sense of priorities when we’re in front of our computer screens. For one thing, email comes at unpredictable intervals, which, as B. F. Skinner famously showed with rats seeking pellets, is the most seductive and habit-forming reward pattern to the mammalian brain. (Think about it: would slot machines be half as thrilling if you knew when, and how often, you were going to get three cherries?) Jessie would later say as much to me when I asked her why she was “obsessed”—her word—with her email: “It’s like fishing. You just never know what you’re going to get.” More to the point, our nervous systems can become dysregulated when we sit in front of a screen. This, at least, is the theory of Linda Stone, formerly a researcher and senior executive at Microsoft Corporation. She notes that we often hold our breath or breathe shallowly when we’re working at our computers. She calls this phenomenon “email apnea” or “screen apnea.” “The result,” writes Stone in an email, “is a stress response. We become more agitated and impulsive than we’d ordinarily be.”