Wellness, Home & Lifestyle, Science & Tech

Overnight Therapy

Matthew Walker

Lesson time 09:20 min

Sleep has a profound effect on our mental and emotional health. Matthew explains why.

Students give MasterClass an average rating of 4.7 out of 5 stars

Topics include: Emotional First Aid • Reading People’s Emotions


[MUSIC PLAYING] - Many of us have a sense that sleep and emotions interact in some meaningful kind of way. It's perhaps that idea of a parent holding a child. And the child is crying, and they look at you and they say, well, they just didn't sleep well last night, as if there's some universal parental wisdom that bad sleep the night before equals bad mood and emotion reactivity the next day. But exactly how does a lack of sleep impact our emotional brain? And as a consequence, our emotional integrity? Well, several years ago, we wanted to do a study to try and understand more about this relationship, so we took a group of healthy adults and we either gave them a full night of sleep or we sleep deprived them. And then we put them in a brain scanner. And we decided to focus on one particular area of the brain-- a deep emotional center called the amygdala. And the amygdala is one of the centerpiece regions for the generation of strong, impulsive, emotional reactions, including negative reactions. Now, when we looked at that deep emotional center, the amygdala, what we found is that in those people who had had a full night of sleep, there was a nice, controlled, modest degree of reactivity. It wasn't as though there was no reactivity at all, but there was an appropriate degree of a response. But in those people who were sleep deprived, the amygdala had become hyperreactive. In fact, the amygdala was almost 60% more responsive under conditions of a lack of sleep. But why was the deep emotional center so erratic-- so sensitive without sleep? And we went on to discover that there was another part of the brain that was involved. This part of the brain sits directly above your eyes, and it's called the prefrontal cortex. And it's a part of the brain that's perhaps most evolved in us human beings. It's thought to be sort of the CEO of the brain. It's very good at making high-level, executive, top-down control decisions and reactions. And one of the things that it regulates is this deep emotional center-- the amygdala. Now, when we looked at those people who'd had a full night of sleep, there was a nice, strong communication pathway from the prefrontal cortex down to the amygdala, regulating it. But in those people who were sleep deprived, that connection had essentially been severed, as it were. And so now, without sleep, we become all emotional accelerator pedal, and too little regulatory control brake, as it were. And what was perhaps more concerning to me is that this represented a neurological signature that is not dissimilar to numerous psychiatric illnesses. And in fact, we're now finding significant relationships between sleep disruption and disorders such as depression, anxiety, including PTSD, schizophrenia, and most recently and tragically, suicide as well. Indeed, in the past 20 years, I have not been able to discover a single major psychiatric condition in which sleep is normal. So I think sleep has a profound story to tell ...

About the Instructor

As a professor of neuroscience and psychology at UC Berkeley and the director of the Center for Human Sleep Science, Matthew Walker is an expert on sleep. In this class, he will illuminate the science behind sleep and teach you how to increase the quality and quantity of your sleep. Learn how to prevent sleep debt, navigate the effects of alcohol and caffeine, and improve your health. Your best sleep starts tonight.

Featured Masterclass Instructor

Matthew Walker

Neuroscience professor Matthew Walker teaches you the science of sleep and how to optimize it to better your overall health.

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