Have you ever woken up in the middle of the night and been relentlessly bombarded by worries? Perhaps you start dwelling on your problems, regrets creep in, or impulses you thought you’d overcome resurface, and you end up devouring half a kilo of ice cream or eating the rest of the cake you’d saved in the fridge.
After midnight, negative emotions tend to capture our attention far more than positive ones, dangerous thoughts become more appealing, and inhibitions disappear. In fact, numerous studies suggest that our minds function differently at night.
Why does the “dark side” of the brain activate at night?
Neuroscientists at the University of Arizona believe the explanation lies in our circadian rhythm. Essentially, the body and mind follow a natural 24-hour cycle of activity that influences our emotions and behavior. During the day, for example, molecular levels and brain activity adjust to a state of wakefulness. But at night, this habitual behavior is disrupted.
This theory makes sense from an evolutionary point of view because, although night is ideal for resting, it was also the time when our ancestors were most at risk, as they could become easy prey for predators.
According to researchers, to cope with this increased risk, our attention intensifies at night, focusing more on negative stimuli to keep us safe. In other words, at night our minds develop a negativity bias. For this reason, a sound we barely notice during the day can startle us quite a bit when it’s dark.
Interestingly, a study conducted at the University of Pennsylvania found that the suicide rate triples between midnight and 4 a.m. It has also been observed that the urge to consume alcohol or drugs increases at night. People with addictions may be able to control their cravings during the day, but they succumb to them at night.
Of course, some of these behaviors could be explained by lack of sleep or the refuge and sense of anonymity or loneliness that come with darkness, but much deeper neurological changes also play a role. Neuroscientists indicate that “Nighttime wakefulness triggers cortical activity at a time when synapses are saturated and cortical responses are impaired.”
This could force the prefrontal cortex, responsible for planning, reasoning, and impulse control, to work overtime. At the same time, an overactive amygdala might assign an incorrect or excessive emotional significance to neutral stimuli, leading to risky behaviors or a tendency to dwell on problems and worries.
In short, we are more vulnerable at night, both to being overwhelmed by the worries and fears we’ve kept under control during the day and to succumbing to temptation. Being aware that our brain doesn’t function the same way will help us take preventative measures and not rely so heavily on willpower.
References:
Tubbs, AS et. Al. (2022) The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology. Front. Netw. Physiol.; Frontiers; 1:10.3389.
Montero-Moraga, JM et. Al. (2020) Impact of 24-hour schedule of a drug consumption room on service use and number of non-fatal overdoses. A quasi-experimental study in Barcelona. Int J Drug Policy; 81: 102772.
Perlis, M. et. Al. (2014) When Accounting for Wakefulness, Completed Suicides Exhibit an Increased Likelihood During Circadian Night. Sleep; 304498989.
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