Khaberni - Most people face fleeting moments of mind wandering, which many consider a worrying or undesirable phenomenon, but a new study has revealed the opposite and concluded that this involuntary condition is actually a "brain cleansing cycle," similar to sleep in which the body and brain rest from strain and fatigue.
The new study, results published on "Science Alert" and reviewed by "Alarabiya.net", indicates that these short mind wandering episodes are attempts by the brain to carry out maintenance processes that normally occur during sleep.
The study, conducted by researchers at the Massachusetts Institute of Technology in the United States, used brain measurements obtained using electroencephalogram devices and functional magnetic resonance imaging.
Periods of mind wandering, or "attention failure" as termed by the study, coincided with a wave of cerebrospinal fluid flowing out of the brain before returning after a second or two.
These patterns matched the cerebrospinal fluid waves that typically occur during deep sleep. It is believed that this nocturnal fluid flow helps wash away wastes that accumulate during the day.
Laura Lewis, a neuroscientist at the Massachusetts Institute of Technology, says, "If you don't sleep, the waves of cerebrospinal fluid start to sneak into wakefulness where you usually don't see them."
She added, "However, they come at the level of attention, where attention fails during the moments when this wave of fluid flow occurs."
The participants in the study were tested twice: once after a night of restful sleep and again after spending a night in the lab without any sleep at all. As expected, their cognitive performance during the study tests was generally worse when they did not get enough sleep the previous night.
While mind wandering sometimes occurred after a full night's sleep, it was much more common after the participants stayed awake all night. It seems as though the brain tries to compensate for the lack of sleep with a bout of light sleep, at the expense of temporarily losing mental focus.
Neuroscientist Zinong Yang, who led the study, says, "One way to think about these events is that your brain desperately needs sleep, so it tries its best to enter a state resembling sleep to restore some cognitive functions."
He added, "Your brain's fluid system tries to restore its function by pushing the brain to navigate between states of high attention and high fluid flow."
The "Science Alert" report states that sleep is extremely essential for our health and well-being, while deprivation from these rest periods increases the risk of diseases, causes weaknesses in certain parts of the brain, and alters our view of the world. This study shows some ways in which the brain tries to compensate for the lack of sleep.
While the inflow and outflow of cerebrospinal fluid were the most significant physiological changes accompanying the loss of focus, researchers also found a slowdown in breathing rate, heartbeats, and a contraction in pupil size.
The researchers did not discuss these findings in great detail, but they hypothesize that periods of mind wandering may affect the entire body and may be controlled by a single control system.
Lewis says, "These findings indicate the presence of a unified neural circuit that controls what we consider high-level brain functions, such as attention and the ability to perceive the world and interact with it, in addition to basic physiological processes like the dynamics of brain fluids, blood flow throughout the brain, and vascular constriction."
