Summary
Andrew Huberman explains the distinct roles of slow-wave (non-REM) sleep and REM sleep in learning, emotional processing, and trauma recovery. Slow-wave sleep, dominated by serotonin and occurring primarily early in the night, is critical for motor learning and detailed information retention. REM sleep, which increases toward morning, is characterized by the complete absence of norepinephrine — meaning we cannot experience fear or anxiety during REM dreams, even while hallucinating vivid scenarios.
This neurochemical dissociation makes REM sleep a natural form of emotional therapy, allowing the brain to replay and process emotionally charged experiences without the associated distress. Huberman draws a direct parallel to EMDR (Eye Movement Desensitization and Reprocessing) therapy, explaining that lateralized eye movements suppress amygdala activity and help decouple emotions from traumatic memories. He also discusses how ketamine therapy shares features with REM sleep's neurochemistry. Practical tools include optimizing sleep architecture to get adequate REM, using NSDR protocols to fall back asleep if waking early, and understanding that REM deprivation leads to emotional irritability and catastrophizing.
Key Points
- Slow-wave sleep (early night) is critical for motor learning and detailed memory consolidation; dominated by serotonin with no acetylcholine
- REM sleep (increasing toward morning) features zero norepinephrine, allowing emotional processing without fear or anxiety
- During REM, the brain replays experiences and establishes meaning by strengthening relevant associations and discarding irrelevant ones
- REM deprivation causes emotional irritability, catastrophizing, and an inability to properly uncouple emotions from experiences
- EMDR therapy works by using lateralized eye movements that suppress amygdala activity, similar to the eye movements generated during walking
- Ketamine therapy shares neurochemical features with REM sleep, both operating in the absence of norepinephrine
- Using NSDR protocols when waking at 3-4 AM helps people fall back asleep and access the REM-rich sleep of early morning hours
Key Moments
How EMDR was discovered: Francine Shapiro noticed walking reduced emotional load of traumatic memories
EMDR originated when Francine Shapiro noticed that walking in the forest reduced the emotional weight of a troubling memory. She translated the lateral eye movements of walking into a clinical therapy protocol.
"And she realized that as she was walking, the emotional load of that experience was not as intense or severe."
EMDR works best for single-event trauma, not prolonged experiences like an entire divorce
EMDR alleviates emotional potency of traumatic memories, especially single-event or repeated specific traumas. Ketamine is also being explored in ERs to blunt emotional encoding of acute trauma.
"The emotional potency is alleviated. Now, EMDR, I should just mention, tends to be most successful for single event or very specific kinds of trauma that happened over and over, as opposed to say an entire childhood or an entire divorce. They tend to be, it tends to be most effective for single event kinds of things, car crashes, et cetera, where people can really recall the events in quite a lot of detail. It's not for everybody and it should be done, if it's going to be done for trauma, it should be done in a clinical setting with somebody who's certified to do this. But that bears a lot of resemblance to REM sleep, right? This experience in our sleep where our eyes are moving, excuse me, although in a different way, but we don't have the chemical epinephrine in order to generate the fear response. And yet we're remembering the event from the previous day or days. And then now there's this chemical treatment with the drug ketamine, which also bears a lot of resemblance to the sorts of things that happen in REM sleep. Ketamine is a dissociative anesthetic. It is remarkably similar to the drug called PCP, which is certainly a hazardous drug for people to use. Ketamine and PCP both function to disrupt the activity of a particular receptor in the brain called the NMDA receptor, N-methyl deaspartate receptor. This is a receptor that's in the surface of neurons or on the surface of neurons for which most of the time it's not active. But when something very extreme happens and there's a lot of activity in the neural pathway that impinges on that receptor, it opens and it allows the entry of molecules, ions, that trigger a cellular process that we call long-term potentiation. And long-term potentiation translates to a change in connectivity so that later, you don't need that intense event for the neuron to become active again. Ketamine blocks this NMDA receptor. So how is ketamine being used? Ketamine is being used to prevent learning of emotions very soon after trauma."
How to get more REM sleep: early adrenaline, avoid alcohol/THC, add 10-30 min to sleep
REM sleep is critical for emotional processing and learning. Exercise or cold exposure in the morning, avoid alcohol/THC (which suppress REM), limit fluids before bed, and add 10-30 min of morning sleep.
"Alcohol and marijuana are well-known to induce states that are pseudo-sleep-like. They dramatically disrupt the pattern of sleep."
