Nov 30, 2020 21:00:00

It turns out that cognitive ability declines if sleep time is too long or too short

New research results have been announced that the fine structure of the brain region '

white matter ', which is said to be related to the capacity of working memory , is affected by sleep time. The study found that cognitive decline occurred when sleep was too long or too short.

Sleep duration is associated with white matter microstructure and cognitive performance in healthy adults --Grumbach --2020 --Human Brain Mapping --Wiley Online Library
https://onlinelibrary.wiley.com/doi/10.1002/hbm.25132

Brain mapping study links abnormal sleeping patterns to decreased white matter integrity
https://www.psypost.org/2020/11/brain-mapping-study-links-abnormal-sleeping-patterns-to-decreased-white-matter-integrity-58647

It is known that sleep is greatly related to the cognitive ability that a person can exert, and existing research has confirmed that 'cognitive ability decreases in a state of lack of sleep'. A group of brain scientists at the University of Westfahren-Wilhelm (Münster University) in Germany used existing datasets to study the relationship between sleep and cognitive abilities in sleep time, sleep quality, cognitive abilities, and brain white matter. We investigated the relationship in integrity (how much white matter nerve fibers are aligned in one direction and how strong they are).

The research team is based on research data from the

Human Connectome Project, a large-scale research project on Connectome that maps how elements in the nervous system are connected, conducted by the National Institutes of Health in the United States. In addition to brain scan data of 1065 adults, we obtained the results of cognitive ability tests and questionnaires on sleep quality and sleep time. We examined these results to see if there was a relationship.

As a result of the survey, it was found that the subjects who slept too short had decreased integration of the superior longitudinal fasciculus of the brain white matter, which is important for working memory and language processing, and also decreased cognitive ability. On the other hand, subjects who slept too long did not show any decrease in white matter integrity, but found that they had decreased cognitive ability. Also, no association was found between sleep quality and cognitive ability.

Regarding this result, the research team declined, 'It is just a relationship, it does not show a causal relationship that sleep time causes changes in brain structure and function,' he said, 'previous research. The results suggest that sleep deprivation alters the chemistry of the brain and impairs the integrity of the white matter. ' Regarding sleep time that does not adversely affect cognitive ability without impairing the integrity of the white matter, 'The optimal sleep time is different for each person, but those who sleep an average of 7 to 8 hours have high cognitive ability. I know it works. '