Sleep deprivation can have a significant impact on our ability to concentrate and focus. A recent study conducted by Laura Lewis and her team at the Massachusetts Institute of Technology sheds light on why this may be the case. According to their research, sleep-deprived individuals experience lapses in attention because their brains are trying to refresh themselves through a process known as the rinse cycle.
During sleep, cerebrospinal fluid (CSF) is flushed into the brain and out again at the base, clearing out metabolic waste that has accumulated throughout the day. This cleansing process is crucial for maintaining the health of brain cells and ensuring optimal cognitive function. However, when individuals are deprived of sleep, the brain attempts to catch up on this cleaning process while they are awake, leading to moments of reduced focus and attention.
In the study, 26 participants were asked to have a good night’s sleep followed by a night of sleep deprivation in a lab setting. MRI scans were used to monitor their brain activity while they performed tasks that required them to respond to specific stimuli. The results showed that participants were more likely to experience lapses in attention when sleep-deprived, with these lapses occurring just before and after CSF was flushed in and out of the brain.
According to Lewis, the brain-cleaning process can be compared to a washing machine, where water is sloshed around to remove impurities. When this process occurs during waking hours due to sleep deprivation, it can interfere with concentration and focus. Understanding the brain circuits involved in this cleaning process could potentially lead to strategies for mitigating the cognitive effects of sleep deprivation.
Overall, this study highlights the importance of sleep for cognitive function and underscores the need for adequate rest to support brain health. By prioritizing quality sleep, individuals can help ensure that their brains have the opportunity to refresh and rejuvenate, leading to improved focus and attention during waking hours.

