MONTREAL — Too much sleep could be detrimental to the cognitive performance of the brain, say canadian researchers.
The preliminary findings of the largest study ever conducted on the sleep confirm that people who sleep seven or eight hours per night have better cognitive performance than those who sleep less or more.
More than 40,000 people from around the world have responded to the long questionnaire scientific put online in June 2017 by the researchers of the institute for Brain and Mind, university of Western Ontario. This questionnaire asked in particular about their medication, their age, their place of residence and their level of education.
Approximately half of the participants reported sleeping less than 6.3 hours per night, or about an hour less than is recommended. An astounding revelation: the cognitive performance of participants who slept four hours or less corresponded to the one of people nine years older than them.
All adults, regardless of their age, seem to need seven or eight hours of sleep and then present a cognitive performance optimal. The reduction associated with too much or too little sleep was also no link with age.
The lead author of the study, Conor Wild, explained that the cognitive performance of “people who slept more than seven or eight hours) was as impaired as that of those who slept too little”.
The reasoning and verbal abilities are among the skills most affected by sleep amount.
But even a single good night of sleep seems to be able to repair the damage: the performance of people who had had a better night sleep than usual just before participating in the study was higher than that of people who had slept as much as usual or less.
The preliminary findings of the study were published this week by the scientific journal Sleep.