Sleep, fatigue, memory

What is the impact of confinement on our sleeping habits, on mental fatigue, and on the memories we create?

Christina Schmidt and Fabienne Collette are psychology researchers and work at the GIGA-Centre de Recherches du Cyclotron at the University of Liège. Together with their colleagues, Christine Bastin and Sylvie Willems, they have launched an online survey to understand the impact of this crisis and our feelings about three pillars of daily life: sleep, fatigue and memory.

Sleep, fatigue, memory: that is the subject of the online survey you have launched during this unprecedented situation of confinement. Why did you decide to research such a topic ?

Christina Schmidt: We are usually exposed to a lot of daily stimulation and experience relatively close social and professional ties. The confinement we are experiencing is unprecedented and has changed our lifestyles.

In particular, flexibility or additional constraints on working hours (depending on the job) can directly affect our sleep-wake cycle and the fatigue we feel on a daily basis. In addition, the strong emotional dimension of a health crisis such as this can alter the creation of autobiographical memories.

Through our online survey, we will examine how these dimensions are impacted by the current confinement and how they interact (e.g. the relationship between sleep and memory consolidation, the impact of a bad night's sleep on cognitive fatigue).

Fabienne Collette: Collecting this data will allow us to better understand our cognitive functioning as well as help us better anticipate the psychological impacts on the population if confinement were to occur again in the future. In fact, a great many researchers from around the world are currently working on this type of question.

The days are similar, and schedules tend to be blurred: how does this affect our nights ?

Christina Schmidt: How do the "confinement" work schedules affect people’s sleep patterns? Generally speaking, we know that the more we sleep in a way that is in tune with our own biological rhythm, the better we recover.

We could say that after an initial period of adaptation to confinement, during which we have "learned" how to manage the situation and function adequately, each person has switched to a sleep-wake schedule corresponding to their personal needs, thus giving the feeling of quality sleep, with an endogenous rhythm that corresponds to it! An "evening" person would therefore no longer have to worry about reconciling going to bed late with a tough morning, as they can shift their working hours. This is the theory.

What we want to understand is how the "external time givers" (i.e. constraints) really give rhythm to our confinement. There is of course daylight, the alarm clock, the (tele)working schedule (or lack thereof), family management, etc.

When these “time givers” weaken, our internal clock has more difficulty synchronising with "external" time, which can again indirectly affect our quality of sleep.

Why does the feeling of tiredness seem particularly strong at this time ?

Fabienne Collette: At the moment, it's quite common to hear people saying "I feel so tired when I'm not doing anything physically demanding". In fact, alongside the phenomenon of physical fatigue, that is easy to identify (after sport, for example), there is also the phenomenon of mental fatigue (for example, having to stay focused on a very specific task for a long time), to which we often pay less attention. It is quite normal to feel a bit of cognitive fatigue on a daily basis, but if all our mental resources are exhausted, then this becomes problematic, with a risk of burning-out. The current lifestyle of hyperstimulation (out of confinement!) is likely to lead to this.

In confinement, all our habits have been disturbed. While at first we may have thought "finally, I have some time for myself", we now see that it's quite the opposite, and that a range of tasks, concerns and adaptations - including, of course, telework and family management - require a lot of mental energy because they are different from the way we normally function. This confinement is very resource-intensive, and the brain gets tired of it. Hence the importance of getting a good night's sleep in order to recover.

What about stress and anxiety too ?

Christina Schmidt: Stress, anxiety, and feelings of uncertainty about the future, have a major influence on sleep, to the point that they can cause insomnia and, consequently, lower-quality sleep. A sedentary lifestyle also affects the quality of sleep, which is deeper with physical activity. There is a whole cocktail of situations at play.

Fabienne Collette: This background of latent anxiety, the questions related to deconfinement, and worrying about a second wave of confinement, also draw on our cognitive resources. For the moment, it's likely that many people are coping because they have no choice, and that they are exhausted having to manage the situation as best they can. What about recovery afterwards? The summer holidays will be welcome to allow us to recover from the mental overload induced by confinement.

The question of memories is also one of the axes of your research. Why is that ?

Fabienne Collette: Memories and recollections define us as individuals belonging to a social group. The living environment has fundamentally changed with confinement. However, memories are born of interactions between people and the variety of situations experienced. Here, for the most part, we are in the same space with the same people (or alone), often having the same days and getting information from the media or social networks, but much less from direct interlocutors than was the case before. To what extent will this "frozen" context influence the creation of memories? Will they be vivid? Will they be emotionally charged? Will they be detailed? How will the characteristics of these memories relate to our sense of well-being?

Participate to the survey

Christina Schmidt is a qualified FNRS researcher and works at the GIGA CRC In vivo Imaging Research Centre at the University of Liège. She is a member of the PsyNCog Research Unit of the Faculty of Psychology, Logopaedics and Educational Sciences, where researchers are conducting multidisciplinary research into human cognition. Christina Schmidt specialises in cognitive neuroscience, with a focus on the impact of the sleep-wake cycle on cognitive aging.

Fabienne Collette is research director and works at the GIGA CRC In vivo Imaging Research Centre at the University of Liège. She is a member of the PsyNCog Research Unit of the Faculty of Psychology, Logopaedics and Educational Sciences, where researchers are conducting multidisciplinary research into human cognition. Fabienne Collette specialises in cognitive neuroscience and is interested in the effects of aging on the brain and cognition