Just a dream?

Publications are as much a part of science as lectures or talks. They only cause surprises when they suddenly arouse such great interest on the part of the media and society that even the most experienced and much-cited researchers are astonished. Daniela C. Rößler was also surprised when her article on “REM sleep-like state in jumping spiders” suddenly received enormous media attention.

Her article “Regularly occurring bouts of retinal movements suggest a REM sleep-like state in jumping spiders” was published in the scientific journal Proceedings of the National Academy of Sciences (PNAS) in the summer of 2022 and generated a great deal of coverage in national and international media. National Geographic, for example, recognized Daniela Rößler’s research as one of the “22 most amazing discoveries of 2022”. 

The research results of Daniela Rößler and her team suggest that jumping spiders (Evarcha arcuata) experience a state similar to active REM sleep in humans. They recorded and analyzed nocturnal infrared footage of 34 young jumping spiders. The spiders exhibited phases of clear retinal movements that took place at very regular intervals. These phases increased in length over the course of the night. The retinal movements were always accompanied by uncontrolled movements of the body, like curling of the legs or twitching of single limbs or the spinnerets. These are surprising similarities to REM sleep seen in other animals.

We talked to Daniela about her experiences with such a huge media response:

Dear Daniela, in a few sentences: What is the aim of your research?

My aim is to contribute to a better understanding of the natural world and the living beings we share this planet with. I am broadly interested in animal behaviour. During my doctoral degree, my research focused on animal colouration and signalling in predator-prey contexts. More recently, since our discovery of a REM sleep-like state, my interest has shifted towards sleep in animals, particularly in those for which we do not know anything yet. That said, my research is almost always based on natural observations that lead me to small – or big – discoveries. I love exploring things we still know nothing about and making new observations. The thought of seeing something that maybe no one has seen before is quite exhilarating! Overall, I think that the kind of research I do generates a lot of public interest, which is fantastic because the more we manage to spark curiosity and interest about the natural world, the better we will hopefully become at protecting it. 

What were the main results of your study?

In our study, we were able to show that jumping spiders spend all night in a sleep-like state with a characteristic posture and with almost no movement during that time. However, in regular intervals throughout the night and with increasing duration, these spiders experienced sleep-like phases that have incredible similarity to REM (rapid eye movement) sleep in mammals and birds. Spiders twitch during those bouts that last about 1.5 minutes, their legs curl up, likely as a result of muscle atonia. The wildest part was that every single one of those REM-like bouts included visible retinal movements. This finding seriously challenges what we know about REM sleep, its function and its origin. In humans, REM sleep is associated with narrative and intense dreaming, thus, one might want to ask: Do spiders dream???

Can you describe your experiences with different media? What did you like, what not?

I loved the genuine interest and fascination this publication generated. Almost every reporter I talked to was just so positive and curious. Of course, some are better prepared than others or some asked more interesting questions than others. And it also has to be said that almost every journalist wanted to know if spiders dream (which was not the point of the study!). Let me say a few things about the different media:

General interviews (Zoom, phone, emails): The general interviews were quite time-consuming, especially when a time-sensitive Zoom meeting had to be set up across different time zones. Phone calls were rare for written interviews, much more common for radio shows. Email interview requests where all questions were sent via email were great because I could reply in my own time and was able to think a bit more about my answers. Being stressed or between other meetings when doing a Zoom interview sometimes led to me not being able to reply as I would have liked to. Often, right after the interview ended, new thoughts popped up of what I could have replied instead. 

Podcasts: I truly enjoyed podcasts because the ones I did were very well-organized and the hosts were well-prepared. The questions were usually different from the general interviews, and I felt like podcasts often went the extra mile of asking questions in a broader context and also inviting experts from other fields, so those were great. 

TV: Very cool experience – extremely time-consuming. Filming what in the end became a 5-minute clip basically took a whole day. The team was great and nice and very interested, but yes, be prepared that TV stuff takes a lot of time.

Radio shows (live or recorded): Radio shows were usually asking for a phone call or skype call to either put you on a show live or record a short interview. My experience with radio shows was quite mixed, especially with brief live radio shows. I understand that radio is a fast medium and time is precious. I just felt that some shows wanted to cover it, but the hosts were not prepared for this topic, so many of those shows quickly took a bad and simple turn into how terrible spiders are rather than being about the actual research, so these shows felt like a waste of my time. (Let me stress that this was not true for all radio shows!).

After all these experiences, what can you recommend other fellows with respect to requests from/interviews with public media?

I enjoyed talking to some of the reporters so much that I am still in touch with them. I can only recommend building a network of journalists that you connect with. Reach out to them before your next publication, see if they would like to cover it. I think having such a network can be just as important as a good network of collaborators. Knowing people who can truly reach the public and that are great at science communication are so valuable to have around!

What are your future research plans? Which research trips, etc.?

I am planning a large-scale project on sleep across spiders to explore the function, ecology and evolution of sleep. We see the same patterns of REM-like behaviour in (so far) all spider families and this gives us an opportunity to investigate how sleep and REM-like sleep evolved in this group. Spiders are a great system in which we can experimentally test the function of sleep and particularly REM sleep. We will also attempt to unravel the “dream” question in our experiments. Moreover, and because jumping spiders have a clear day/night rhythm, we will study their sleep in the natural habitat to better understand the role of ecological factors such as climate or predator presence. Exploring sleep in a comprehensive and evolutionary framework can contribute to a better understanding of (REM) sleep, including in humans. We know very little about the origin and function of sleeping and dreaming (not synonymous with REM sleep!) and I really hope we can add a little piece to the puzzle!

To do this, we will need a broad taxonomic sampling, which will include research trips in and outside Europe. Currently, my plan is to focus on spiders in Portugal, Panama and Australia, where we will film spiders sleeping in the field!! 
That is, if I manage to secure funding for the project 😉