The Yin and Yang of Sleep and Attention

Emerging scientific evidence is suggesting that sleep serves several distinct functions. We have all experienced the bad days in school and at work when we didn’t get enough sleep the night before and we have a hard time focusing. In animals like worms with simple nervous systems, sleep-like states are associated with development and environmental stress, while animals like mammals and humans, sleep also has a major role in supporting cognitive processes, such as learning and attention. The need for sleep is increased by behaviors that require selective attention and operant learning. So, Leonie Kirszenblat hypothesizes that though sleep and attention have been viewed as fundamentally different states, they may involve similar mechanisms for suppressing external stimuli.

In her study at the Queensland Brain Institute in Australia, PhD student Kirszenblat says that since sleep and attention have mutual effects on each other, they seem to be complementary like the yin and yang of Chinese Philosophy in which contrary forces combine to create harmony. “This is a revolutionary way of thinking about how the brain works during sleep and wakefulness,” Kirszenblat’s supervisor, Professor Bruno Van Swinderen said, “Although sleep and attention seem like opposite brain states, they both essentially help an animal to ignore the outside world.”

An idea has been emerging that suggests that sleep is inextricably linked with synaptic plasticity (the strengthening or weakening of synapses in the nervous system as a result of experience). So if sleep is linked to plasticity, what is the consequence of losing sleep? Obviously one effect of having a bad night’s sleep is the inability to pay attention effectively the next day. Kirszenblat found that when we are sleep deprived, our reaction times are much slower and behaviors become unstable and unpredictable. But though attention is affected, basic sensory responses, such as vision and auditory processing, remain largely intact. Sleep deprivation also affects our ability to deal with large amounts of information, and disrupts functional connectivity between different brain regions. Kirszenblat also held experiments on sleep and learning processes and found that learning processes that require more attention amd more coordinated activity across the brain have a greater dependency on sleep.

Looking at her study, it is obvious that sleep affects our attention. However, she has done very little research in seeing whether attention affects our sleep. In order for her to state that attention and sleep act like yin and yang, attention must also play an important role in regulating our sleeping patterns. Though attention may affect sleep, Kirszenblat did not do any experiments on this idea, she focused heavily on the sleep side of her argument. Further research needs to be done in order to say that attention affects sleep.

Kirszenblat, L. (2015). The Yin and Yang of Sleep and Attention. In Trends in      Neurosciences (Vol. 38, pp. 776-786). Netherlands: Elsevier Science.