Ayesha Rascoe de NPR speaks with Professor Nicole Tang about sleep quality and why it is difficult to define and measure.
Ayesha Rascoe, host:
Sleep – It is the Holy Grail of good physical and mental health, and we all know what it does not have enough. Where are we? Sleep researchers note that the opinion of participants in the study of sleep on their quality of sleep differs with what the supervisors of the machines reported. In other words, you might feel well rested, but your sleep data can say the opposite and vice versa. Nicole Tang is the director of the Warwick Sleep and Pain Lab at the University of Warwick, and she is now joining Coventry, England. Welcome to the program.
Nicole Tang: Hello.
Rascoe: It therefore seems that there is a difference between the data that researchers collect in sleep studies using objective equipment and the way in which the subjects feel rested. Does this mean that a good night’s sleep is, like a subjective thing?
Tang: Well, it’s a very good question. And I think you have highlighted a very interesting phenomenon these days, because many people wear a sleep tracker now when they fall asleep. And sometimes, when they wake up in the morning, they will watch the watch, and the watch can give them a score – how much they slept – with other data – how long they sleep and others more complex index . Sometimes people feel that, well, I don’t quite feel what they have said, and I would say that the way you feel sleep is just as important as what watches tell you.
Rascoe: There is also, you know, data that you get sleep studies where people are really connected to very intensive machines and things of this nature. What do these machines tell you about how rested people are, and is it different from what people say they feel?
Tang: So I think what you are talking about are machines that we call polysomnography. So, when you put electrodes on the head of people, try to obtain measures of electrical activity around the scope with other physiological measures, such as ECG to measure the heart rate – these will provide important physiological measures.
Thus, the way they define sleep is very different from the information that we, as a sleeper, would use to judge sleep. When you see sleep through the objective of technology, you actually talk about different parameters that people use to define sleep. But when you talk to a human, they told you about experience.
Rascoe: Is there a reason why people can feel different from what an objective measure would do? Is it because he is so personal and we all have our kind of different rhythms?
Tang: The quality of sleep can be a judgment, and at different times of the day, you can find different notes or a different judgment, depending on the information that comes to mind. When we have had this experience, we asked people to give us on several occasions, to give ourselves notations on sleep. And we discovered that what they are doing during the day would change their decision. For example, if they are in better mood and also in particular when they have been engaged in positive physical activity, it helps them think better of their sleep.
Rascoe: You know, according to the American Psychiatric Association, about a third of American adults say they have trouble falling asleep, staying asleep or both. From the point of view of science, what is a good night’s sleep in terms of length or quality?
Tang: For scientists, we don’t really have a good answer which is exactly the quality of sleep.
Rascoe: Are you already having trouble sleeping? And what are you doing when you have trouble sleeping?
Tang: right. ALL RIGHT. So I am a human, so I find it hard to sleep sometimes too. There are things you can do to help calm the mind. Breathing exercise – So what you can also do is not try to fall asleep when your body is not ready. So, to cut frustration, do something boring, like reading a very boring novel, you go back to bed and try to sleep again.
Rascoe: Read a boring book.
(LAUGH)
Rascoe: I will not ask you any recommendations for this. It is Nicole Tang, director of Warwick Sleep and Pain Lab at the University of Warwick. Thank you very much for talking to us today.
Tang: Yeah, my pleasure. THANKS.
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