Essentials: Understand and Use Dreams to Learn and Forget

Andrew Huberman frames this discussion of dreams around two processes: learning and unlearning, particularly the loosening of responses to emotionally challenging events. Introducing himself as a Stanford professor of neurobiology and ophthalmology, he favors an account grounded in sleep physiology over symbolic interpretation. He says much of Freud’s approach has been debunked, while leaving open an interest in what dream imagery might represent.

The organizing framework is a night of roughly 90-minute sleep cycles. In Huberman’s description, earlier cycles contain more shallow and slow-wave sleep, while REM—rapid eye movement—occupies a larger share of successive cycles toward morning. He says this progression occurs even when sleep is interrupted. His central argument is that different stages support different kinds of learning, making the distribution of sleep across the night relevant to both physical skills and emotional experience. He also proposes that daytime activities can influence access to these stages. Later, he identifies resistance exercise as one way to increase slow-wave sleep, while noting that it need not be performed near bedtime.

Huberman describes slow-wave sleep as a metabolically active state marked by large waves of activity sweeping across substantial portions of the brain. To explain its functions, he introduces neuromodulators: relatively slow-acting chemicals that favor the activity of some circuits over others. In his account of waking states, acetylcholine supports focus and attention, norepinephrine supports alertness and the desire to move, serotonin supports well-being and stillness, and dopamine supports pursuit of goals, pleasure, and reward.

He characterizes slow-wave sleep as having essentially no acetylcholine, a small amount of norepinephrine, and abundant serotonin. He connects this pattern with broadly distributed activity rather than sustained attention to a single thing, alongside a distorted sense of space and time. Although people usually remain relatively still, he emphasizes that slow-wave sleep does not involve paralysis: a person can roll over, and sleepwalking typically occurs in this stage.