Researchers call for new studies to find out how our brains change when we’re awake after midnight

Summary: A new hypothesis suggests that when people are awake during biological circadian night, there are neurophysiological changes in the brain that alter the way we interact with the world, particularly in relation to impulse control, processing of information and reward processing.

Source: mass general

If you’ve ever stayed up late angrily commenting on Twitter posts, eating an entire pint of ice cream out of the container, finishing another bottle of wine, or just feeling miserable, you might identify with the Mind Hypothesis. After Midnight.

The hypothesis, which was detailed in a recent article by Frontiers in Network Psychologysuggests that when humans are awake during biological circadian night – after midnight for most people – there are neurophysiological changes in the brain that alter how we interact with the world, particularly actions related to reward processing , impulse control and information processing.

These changes can make you more likely to view the world negatively, engage in harmful behaviors, and make impulsive decisions (including those associated with addictive behaviors such as gambling and substance abuse) without fully considering the consequences.

“The basic idea is that from a high-level global evolutionary perspective, your internal biological circadian clock is tuned to processes that promote sleep, not wakefulness, after midnight,” says Elizabeth B. Klerman. , MD, Ph.D., researcher in the Department of Neurology at Massachusetts General Hospital, professor of neurology at Harvard Medical School, and senior author of the paper.

Klerman describes the hypothesis as a call for researchers to conduct new studies to better understand how these circadian differences affect behavior, decision-making and work performance at night, and to identify strategies that can help people cope.

The findings could have far-reaching effects on people who have to be awake at night to work, including pilots, healthcare workers, police officers and military personnel. The research could also lead to new strategies to reduce violent crime, substance use disorders, suicides and other harmful behaviors.

“There are millions of people who are awake in the middle of the night, and there’s enough evidence that their brains aren’t functioning as well as they were during the day,” Klerman says. “My plea is for more research to look at this because their health and safety and that of others is affected.”

Bad things happen after dark

Previous research has shown that people are at higher risk of engaging in harmful behaviors such as suicide, violent crime, and substance use at night.

For example, Michael L. Perlis, Ph.D., associate professor of psychology at the University of Pennsylvania Perelman School of Medicine and co-author of the Mind After Midnight hypothesis, found that if you adapt to the number of people awake at any time, suicides are statistically more likely to occur at night.

Homicides and violent crimes are also more common at night, as are the risks of illicit or inappropriate use of substances such as cannabis, alcohol and opioids.

Our nighttime food choices also tend to be unhealthy, as we crave more carbohydrates, fats, and processed foods and often consume more calories than we need.

So why does all this bad behavior come out at night?

There are some obvious answers – it’s a lot easier to commit a crime under cover of darkness, for one thing, and there are fewer people around and awake at night to help us control our behavior. But there is probably also a biological basis.

Klerman explains that the circadian influence on neural activity in our brain changes over the course of 24 hours, leading to differences in how we process and react to the world.

For example, positive affect—the tendency to view information in a positive light—is highest in the morning, when circadian influences are attuned to wakefulness, and lowest during the night, when circadian influences are adapted to sleep.

At the same time, negative affect – the tendency to view information in a negative or threatening light is highest at night.

Your body also naturally produces more dopamine at night, which can alter your reward and motivation system and increase the likelihood of engaging in risky behavior.

This biased interpretation of information is then sent to the parts of the brain responsible for decision-making, which normally work to control negative emotional distractions and focus on goal-oriented behavior.

But these parts of the brain are also subject to circadian-influenced changes that can impair decision-making, functioning, and prioritization.

Suddenly, your view of the world narrows and becomes more negative, you start making poor decisions, and the mental map you create of the world around you may no longer correspond to reality.

The result? You could end up drinking too much, missing a crucial patient diagnosis, crashing an oil tanker into rocks, or worse.

Klerman experienced some of those feelings firsthand when she struggled to fall asleep after suffering severe jet lag on a trip to Japan.

“While part of my brain knew I would eventually fall asleep, as I lay there and watched the clock ticking, I was beside myself,” she recalls.

This shows a cartoon of a person lying in bed
The research could also lead to new strategies to reduce violent crime, substance use disorders, suicides and other harmful behaviors. Image is in public domain

“Then I thought, ‘What if I was a drug addict? I would be trying to get drugs right now. Later I realized that could also be relevant if it happened. involved suicidal tendencies, substance abuse or other impulse disorder, gambling, other addictive behaviors How do I prove this?

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This shows a scale and tape measure

Test the hypothesis

The need for proof is essential here. It is important to note that Mind After Midnight is still a hypothesis, which will need to be validated by carefully constructed research studies.

In an ironic twist, the best way to collect this data without the disconcerting effects of sleep loss will require the researchers and study staff themselves to be awake and working after midnight, for example taking fMRI images of study participants whose sleep cycles were carefully adjusted. for nocturnal awakening or the conduct of other protocols.

“Most researchers don’t want to be notified in the middle of the night. Most research assistants and technicians don’t want to be awake in the middle of the night,” Klerman concedes.

“But we have millions of people who have to be awake at night or who are awake at night unintentionally. Some of us will have to be inconvenienced to better prepare them, heal them, or do whatever we can to help them.

About this sleep and psychology research news

Author: Press office
Source: mass general
Contact: Press Office – General Mass
Image: Image is in public domain

Original research: Free access.
“The Mind After Midnight: Nocturnal Awakening, Behavioral Dysregulation, and Psychopathology” by Andrew S. Tubbs et al. Frontiers in network physiology


Summary

The Mind After Midnight: Nocturnal Awakening, Behavioral Dysregulation, and Psychopathology

Sufficient sleep with minimal interruption during circadian/biological nighttime supports daytime cognition and emotional regulation. Conversely, disturbed sleep involving significant nocturnal awakening leads to cognitive and behavioral dysregulation.

Most studies to date have looked at how fragmented or insufficient sleep affects functioning the next day, but recent work highlights changes in cognition and behavior that occur when someone is awake during the night.

This review summarizes the evidence for day-night alterations in maladaptive behaviors, including suicide, violent crime, and substance use, and examines how mood, reward processing, and executive function differ during nocturnal wakefulness.

Based on this evidence, we propose the The spirit after midnight hypothesis that attentional biases, negative affect, impaired reward processing, and prefrontal disinhibition interact to promote behavioral dysregulation and psychiatric disorders.

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