The Mind After Midnight hypothesis suggests that when humans are awake after midnight, certain neurophysiological changes in the brain alter how we interact with the world. These changes can negatively affect individuals' perspectives, lead to harmful behaviors, and result in reckless decision-making (including behaviors associated with addiction such as gambling and drug use) without fully considering the consequences. Researcher Elizabeth B. Clearman from the Department of Neurology at Massachusetts General Hospital and lead author of the study states, "The fundamental idea is that from a high-level evolutionary perspective, your biological clock is set toward processes that promote sleep, not wakefulness, after midnight."
Clearman describes the hypothesis as a call for researchers to conduct new studies to better understand how these daily differences impact behavior, decision-making, and performance at night, as well as to identify strategies to help people cope. The findings could have far-reaching implications for individuals required to be awake at night for work, including pilots, healthcare workers, police officers, and military personnel. Research may also lead to new strategies to reduce violent crime, substance abuse disorders, suicide, and other harmful behaviors. Clearman emphasizes, "There are millions of people awake at midnight, and there is quite good evidence that their brains don't function as they do during the day; I call for more research to look into that, because their health and safety, as well as the health of others, are affected."
Previous research has shown that individuals are more likely to engage in harmful behaviors such as suicide, violent crime, and substance use at night. For instance, Clearman found that statistically, suicide events are more likely to occur during nighttime hours. Additionally, murders and violent crimes are more common at night, as well as the risks of illicit or inappropriate use of substances like marijuana, alcohol, and opioids. Our nighttime food choices tend to be unhealthy as we seek more carbohydrates, fats, and processed foods, often consuming more calories than needed. Why do all these negative behaviors emerge at night?
There are some clear answers; for example, it's much easier to commit a crime under the cover of darkness, and there are fewer people around us awake at night to keep our behavior in check. However, there may also be a biological basis at play. Clearman clarifies that daily effects on neural activity in our brains change over a 24-hour period, leading to differences in how we cope with and respond to the world. The positive effect of “the tendency to present information in a positive light” peaks in the morning when daily influences on wakefulness are heightened, while it is at its lowest during the night when these influences are set towards sleep. Conversely, the negative effect of “the tendency to present information in a negative or threatening light” is highest at night.
Your body also naturally produces more dopamine at night, which may alter your reward and motivation system and increase the likelihood of engaging in risky behavior. This biased interpretation of information is then sent to areas of the brain responsible for decision-making, which typically regulates negative emotional distractions and focuses on goal-oriented behavior. However, these parts of the brain are also subject to changes influenced by the biological clock that can weaken decision-making processes, performance, and prioritization. According to Clearman, suddenly your view of the world narrows and becomes more negative, leading you to make poor decisions; the mental map you create of your surroundings may not align with reality.
With the hypothesis still needing validation, Clearman notes that the need for evidence is key here; it is important to recognize that Mind After Midnight remains a hypothesis requiring validation through carefully constructed research studies.
