The University of Liège Research Center reveals that the body during sleep also responds to the external world, explaining how some information from the sensory environment affects the quality of sleep.
Researchers from the University of Liège collaborated with the University of Fribourg in Switzerland to study whether the human body is really disconnected from the outside world during sleep. To do this, they focused on how the heartbeat changes when we hear different words in sleep. They found that relaxed words slowed heart activity compared to neutral words that did not have this slowing effect, which reflected deeper sleep.
The findings, published in the Journal of Sleep Research, provide new clues to the brain-heart interactions during sleep.
Coloma, Schmidt and Demerz of the University of Liège Research Center, in collaboration with colleagues at the University of Fribourg, conducted a previous study analyzing brain data (EEG) showing that relaxed words increased the duration of deep sleep and sleep quality, showing that we can use meaningful words to positively influence sleep.
The authors hypothesize that after hearing relaxing words during sleep, the brain is still able to interpret sensory information in a way that makes our bodies more relaxed. In the new study, the authors had the opportunity to analyze heart activity (electrocardiogram) to test this hypothesis and found that the heart slows down activity only after the occurrence of relaxation words, not control words.
Markers of heart and brain activity are then compared to find out how much they contribute to the regulation of sleep by auditory information. Cardiac activity is indeed thought to help us perceive the world directly, but to date, this evidence has been obtained in a waking state.
Based on these results, researchers at the University of Liège have shown that the same is true during sleep, which provides a new perspective for our understanding of sleep, namely the important role of bodily responses beyond brain data.
"Most sleep research focuses on the brain, with very little physical activity being studied," says Dr. Schmidt. ”
"Still, we assume that even if we can't fully communicate, including sleep, the brain and body are connected," Dr. Demerz explains. In order to fully understand how we think and react to our environment, we need to consider the information of the brain and body. ”
"We followed the principles of open science and freely shared our approach, hoping that the tools that contributed to this discovery will inspire other researchers to study the role that the heart plays in other sleep functions," Dr. Koroma said. ”
This work provides a more comprehensive approach to the regulation of sleep function through sensory information. For example, by studying the heart's response to sound, we can in the future study the body's role in the emotional processing of sound affecting memory during sleep.
February** Dynamic Incentive Program