Thomas Andrillon, Ph.D. in Cognitive Neuroscience from the Ecole Normale Supérieure (PSL Research University), recently visited the Cognitive Sciences Laboratory at the Universidad del Desarrollo. In recent years Dr. Andrillon has worked in collaboration with Dr. Sid Kouider in Paris (Laboratoire de Sciences Cognitives et Psycholinguistique) and with Dr. Giulio Tononi (Center for Sleep and Consciousness at the University of Wisconsin at Madison, WI, USA) on the following question: how can the brain process information during sleep?

On March 28, Dr. Thomas Andrillon visited Dr. Gabriel Reyes at the Centro de Apego y Regulación Emocional. The following interview took place during that visit.

Question 1: Thomas, tell us about your line of research. What you have spent your time on in recent years and where will your research lead in the years to come?

My principal focus of research is on sleep. Sleep is indeed a very strange phenomenon. It is everywhere in the animal kingdom and yet, it places organisms in a highly vulnerable state depriving them from their ability to respond to potential threats. It is thus quite baffling to see that sleep is preserved even when the environment seems to put an enormous pressure not to sleep: dolphins cannot stop swimming and some migrating birds cannot stop flying. But they both do sleep, one hemisphere at a time! In general, it seems that animals cannot escape sleep but that, somewhat, they manage the associated vulnerability.

Thus, during my PhD, I decided to explore to which extent sleepers remain connected to their surrounding environment. To do so, I used two approaches. One was to investigate the physiology of sleep. Sleep physiology is indeed best known thanks to animal models (rodents, cats) and while a Human brain sleeps roughly the same way, there are some important differences (for example, we spend half of our nights in a state of light sleep that is almost non-existent in rodents). I had the chance to have access to intracranial data in human epileptic patients thanks to an international team in the US (Pr Tononi and Cirelli, University of Wisconsin) and Israel (Pr Itzhak Fried and Dr Yuval Nir, University of Tel-Aviv). Such data allowed us to investigate sleep from single neurons to whole-brain recordings, filling the gap between anima and human research. We surprisingly discovered that sleep was more local than previously pictured. This is important for my angle of research since this means that one brain region can be awake while the rest of the brain sleeps, allowing perhaps for the recovery of specific wake-like processes in a global context of sleep.

 I thus set out to examine the functional consequences of such local sleep. Together with Sid Kouider at the Ecole Normale Supérieure in Paris, we showed that sleeping participants can not only process external information in a complex way (as, for example, distinguishing words referring to animals from words referring to objects) but also that they can even prepare for an appropriate motor response. We replicated these results in multiple ways, concluding that some parts of sleep (like light sleep) allow for complex and flexible information processing. Of course, a natural follow-up question is thus to ask whether sleepers can learn, granted that they have access to sensory stimulations. In subsequent experiments we showed that sleepers could indeed learn but that such learning seems weak and implicit in nature. Most importantly, we showed that in deep sleep, the reverse happens and memories are suppressed in this state. You should thus better think twice before trying to learn something during your nights!

The years to come will hopefully allow me to dive further in the precise mechanisms involved in sensory processing ad learning during sleep, maybe through experiments in animals. I am also getting more and more interested in dreams. I think that comparing dreaming with other states during which we turn inward (such as mind wandering) is a very promising approach.

Question 2: I understand that your research can be classified as part of a (sub)domain of cognitive sciences: the science of consciousness. Indeed, in the last few years you have published studies that relate information processing during sleep and consciousness in important scientific journals (e.g., The Journal of Neuroscience, Nature Communications, Current Biology, Neuron, etc.). So do you think that consciousness has ceased to be placed in the territory of philosophical speculation and has become purely scientific research material?

The study of consciousness has definitely changed and is no longer out of the reach of experimental science. Not all scientists would agree that studying consciousness is a reasonable thing to dedicate to but it is becoming more and more accepted. The time in which consciousness was a taboo word in scientific paper is over. The problem is perhaps now the reverse. A lot of experimental work in cognitive sciences can be linked to consciousness but the term being ill-defined, it often adds more confusion than anything else. I would also say that the danger of experimentalists (as myself) is to think that the theoretical thinking is over and that we can make progress by running experiments in every direction or by shaking the data enough. For this, I agree with my previous supervisor, Giulio Tononi, that a theory of consciousness is desperately needed to orientate experimental work. But consciousness will never be a “purely scientific research material”, there will always be dreamers to find scientific answers unsatisfying and to come up with answers of their own. This will all be fine as long as scientific and unscientific explanations of consciousness won’t be placed on an equal footing in debates regarding individual rights and liberties.

Question 3: In the science of consciousness, what topics do you think research will reveal in the next few years?

It is hard to predict the future, especially in a field as fast-moving as the study of consciousness. I think that one of the great achievements to come, and to come soon, is the ability to determine with a very high precision whether a person is conscious at a given moment. This has huge implications for comatose patients, whose families are often left in uncertainty. Not only will physicians and scientists will be able to determine if a given person is conscious but they will also be able to say what kind of consciousness is left. Such advances will maybe be extended to animals or even machines, revolutionizing perhaps the way we see the world and the way we interact with it. Would you eat meat if you know how cows feel? Would you switch of your computer if you know it has a rudimentary consciousness of its own? Of course, we are not there yet but the empirical tools to quantify and described consciousness in human beings are progressing fast.

Question 4: With respect to the development of your discipline (cognitive neuroscience), what is your diagnosis with respect to the mobility of students to and from European laboratories. Is it important to incentivize student mobility for the education of new researchers? Do you think that CARE (UDD) should opt for internationalization both in terms of doctoral candidates as well as researchers?

Internationalization cannot be a bad thing in the inter-connected world of science. In Europe, there is a good mobility of students but this mobility is not equally shared. Some hubs like Paris, London, and large university cities in the US are very well connected. But connections to smaller cities or institutions are less strong. I personally know more the research done in the US or the UK than in France! Another issue is that many students cannot move because of financial issues. Mobility can have an immense impact during the initial training of students (e.g. moving from one city to the next to follow a given Master program), but moving can be costly. Internships for example are rarely paid and while they can boost an early research experience, not everyone can afford it. I had the chance to be supported by my institution, the Ecole Normale Supérieure, to do research abroad. I wish all my fellow students would have had the same opportunity. Thus, I think that institution that can afford it, should support the mobility of students even at an early stage of their career. By doing so, universities can attract talented and motivated students and, on the long-term, create a network of ambassadors, which will ultimately benefit the university.

Question 5: In your opinion will it be feasible in future to establish a collaborative alliance between your team and the researchers in the Faculty of Psychology at the Universidad del Desarrollo?

This will be of great interest and, from what I have seem of the Faculty of Psychology of the Universidad del Desarrollo, it could represent a very fruitful collaboration. As I said earlier, the world of science is nowadays a very international one but made of big hubs. Increasing the diversity of interactions among researchers would help bringing new ideas and finding new approaches to understand our minds’ mysteries. I hope that Dr Reyes and I will continue our discussion started in Santiago.