Zoning Out: How Your Brain Tries to Catch Up on Maintenance
We’ve all experienced those moments of zoning out, especially when we’re running on little sleep. A recent study suggests that these lapses in attention may actually be our brain’s way of trying to make up for the maintenance tasks it usually performs during sleep.
Conducted by researchers at the Massachusetts Institute of Technology (MIT), the study utilized brain measurements obtained through electroencephalogram (EEG) caps and functional magnetic resonance imaging (fMRI) scanners.
During periods of zoning out, or what the study refers to as “attentional failures,” researchers observed a surge of cerebrospinal fluid (CSF) flowing out of the brain, only to return a moment later. This pattern mirrored the CSF waves typically seen during deep sleep, which are believed to aid in clearing out waste products accumulated throughout the day.
According to MIT neuroscientist Laura Lewis, “If you don’t sleep, the CSF waves start to intrude into wakefulness where normally you wouldn’t see them. However, they come with an attentional trade-off, where attention fails during the moments that you have this wave of fluid flow.”
The study involved participants undergoing tests after a full night of sleep and after a night without any rest. Unsurprisingly, cognitive performance was notably poorer when participants were sleep-deprived.
While instances of zoning out occurred after a well-rested night, they were much more prevalent following a sleepless night. It appears as though the brain is attempting to compensate for the lack of sleep with brief periods of microsleep, albeit at the expense of focus.
Lead researcher Zinong Yang explains, “One way to think about those events is because your brain is so in need of sleep, it tries its best to enter into a sleep-like state to restore some cognitive functions. Your brain’s fluid system is trying to restore function by pushing the brain to iterate between high-attention and high-flow states.”
The findings highlight the critical role of sleep in maintaining overall health and well-being. The study sheds light on how the brain copes with sleep deprivation and the mechanisms it employs to compensate for lost rest.
Aside from the fluctuations in CSF flow, researchers also noted changes in breathing, heart rate, and pupil size during attentional failures. While these physiological alterations were not extensively explored, there is a hypothesis that zoning out may impact the body as a whole through a centralized control system.
Lewis suggests, “These results suggest to us that there’s a unified circuit that’s governing both what we think of as very high-level functions of the brain – our attention, our ability to perceive and respond to the world – and then also really basic fundamental physiological processes like fluid dynamics of the brain, brain-wide blood flow, and blood vessel constriction.”
The study has been published in Nature Neuroscience and provides valuable insights into the intricate interplay between sleep, brain function, and overall well-being.
