Every animal on Earth has a circadian rhythm, a 24-hour cycle that is linked to the sun. Humans have an internal clock that is located in the hypothalamus of the brain. On average, babies sleep 16 hours a day, but these are not consecutive hours. Instead, they are broken up throughout a 24-hour day, resulting in wake and sleep cycles. Babies cycle through wake and sleep rapidly. In fact, over the course of 24 hours, babies can have over 100 wake and sleep cycles!
But as babies begin to grow, their internal clocks begin to regulate. At what age does this occur? Researchers used baby rats to answer this question because baby rats cycle through wake and sleep just as quickly as infants do. In the experiment, researchers put a dye into the brain of a newborn rat, right where their internal clock is located. At first, the researchers saw nothing new in regards to how the red dye spread, but a week later, researchers found that the red dye that was located near the internal clock region had spread closer to the rat’s brain stem. This meant that connections in the rat’s brain were being made and the evidence suggested that the same thing was happening in a newborn. Ultimately, the connections between the internal clock region, the area where the hypothalamus is located, and the brain stem, where the wake and sleep cycles happen, is what regulates the circadian rhythm.
Unfortunately, there is no way for a parent to speed up the process of regulating the circadian rhythm in an infant. Instead, a parent will have to wait for three to four months for these connections to happen naturally.
