What do a man and a green plant have in common? Their waves quiver to the sound of music. At Rencontres Internationales Mondes Multiples de Bourges, online from the 13th of November to the 6th of December, Maria Castellanos and Alberto Valverde recall that homo sapiens is just one living being among others.
Leaves covered with electrodes, Maria Castellanos and Alberto Valverde place plants under electronic surveillance to better monitor their reactions to their sensory environment. For Mondes Multiples, they present Uh513, a collection of works that aim to study the inter-relationships and intersections between machines and human beings. Their researches invoke philosophy, biology, extra-human communication but also pure mathematics, algorithmic art and data visualization. A poetic and interdisciplinary technique at the service of solving a great mystery… what makes plants resonate?
Makery: Your centerpiece is Beyond Human Perception, in which you measure the electrical signal from plants and humans while they listen to music. Are plants sensitive to music?
Maria Castellanos & Alberto Valverde: We started working with plants in 2009. Clorofila 3.0 was the first work that Alberto and I did together. We developed our own sensor to measure plants’ electrical oscillations. We use the same one for Beyond Human Perception.
When you change the plant’s surrounding, like the light, the temperature, the CO2 concentration, even the proximity with people or other plants, the vegetal detects these changes immediately, and, thanks to the sensor, we can measure that. However each plant is different and we need to adapt the sensor to each one. For instance plants with big leaves are slower than the little ones. We can also decide which changes we want to measure : we can for example measure the plant’s reaction do the CO2 change or to the moving of its pot and decide to not record the changes in reaction to the touch of its leaves.
Clorofila 3.0, Maria Castellanos and Alberto Valverde, 2010-2015 :
In the same way than CO2 or light, the plant detects music and its electrical signals change in reaction to it.
You observed that plants and humans’ signals change in the presence of each other…
The idea for Beyond Human Perception experience is born in 2019, during a residency in Oslo. We placed a human and a plant in a situation of strong interaction, where the human was touching the plant, was speaking to it, singing for it, and we observed the human brain’s electrical waves and the plant’s electrical signals. We were extremely surprised to find that when something happens in the human brain, a similar phenomenon occurs in the plant’s signal. This was our starting point.
Experiment with Plants and Humans, Maria Castellanos and Alberto Valverde, 2019 :
Next, we wanted to know if the two living beings would react to a common stimuli without interaction between each other. In this case, we used live music as a stimuli.
What was the result of this experiment?
We now know that plants and humans respond to music and these reactions are much more similar than we expected.
We organized four short concerts for plants and humans. For each, four humans and eight plants were “listening” to live music in the same room and their data were recorded, so they could then be analyzed and compared.
After collecting the data, we process it and turn it into a 3D vizualisation where each living being is represented by a moving figure made up of small spheres. Each sphere represents a data. Looking at the visualization, it is impossible to see the difference between the two, whether we are looking at the plant or the human. It surprised us, we did not expect to observe such similarities.
We experimented with improvised music and can see that both living beings are sensitive to drastic changes in instruments, changes in tones or volume of sound. You can observe these sensitivities by looking at the work.
Beyond Human Perception, Maria Castellanos and Alberto Valverde, 2020 :
How do you compare the two signals?
This is an essential question in our project. In humans, we measure electrical activity by EEG, and in plants, we measure electrical oscillations with our sensor: we connect one part of the sensor on a stem and the other in the soil, next to the roots. In this way, thanks to an algorithm that we have developed, we are able to measure the electrical oscillations that occur in the plant according to its environment, and this immediately.
The two measurements are very different, and we use math to solve this problem. We use the fast Fourier transform algorithm, very common in computer science, to compare different data. This allows us to convert the signal from its original source (in this case, EEG measurements and the plant’s electrical oscillations) into a representation of its frequency. So we get two waves that can be compared and we have developed our own algorithm to transform these measurements into 3D drawings, which makes it possible to observe the similarity of the two beings.
Is there fundamental differences?
What we do know is that we are sure of nothing. We have of course found similarities when we observe the reactions of the two beings but we are very different and we cannot compare ourselves using to the same framework.
For example, some people see the tree’s roots as its brain. But we are discovering that maybe their brain is formed by their whole. We cannot comprehend their nervous system in an anthropocentric way.
Plants always been there, even before humans, yet many think about them as objets. They are living beings. This work, as well as the previous ones, is our way to understand nature a little better.
Currently, we talk a lot about the trees’ intelligence, about mycorrhizal networks between fungi being a natural world wide web… Are we close to recognize a form of consciousness to vegetals?
We follow very closely Stefano Mancuso’s work, an Italian biologist who focuses his researches on plant neurobiology. He explains that in a lot of ways, plants are more sensible than humans: they possess the same five senses that all animals have, and 15 more. So, yes, I think it is another form of consciousness that humans don’t understand yet.
One of our next projects is to work with Artificial Intelligence to explore what is going on in plants that our human brain cannot comprehend. For the next year and a half, we will be working on Other Intelligences. Interspecies Dialogues plant-human. We are going to develop a neural network of plants, which means we are going to connect spatially separated plants through the Internet and see through IA if there can be some form of communication.
There is a lot of research on how plants communicate when close to each other. But what happens when they are at a distance?
In your researches, machines act like an integration factor, a way to multiply humans’ capacities. Going online to respect lockdown could almost be another layer to your work…
It is true that we work with machines, but we produce tangible things. We like to touch, to invite the public to get involved in our installations. It can be difficult to convey these things through a single screen or a website.
We had to adapt, change our methodology. Our EMAP residency started in April, at the same time than the beginning of lockdown in Spain. Instead of being in Croatia, we therefore made our residency from home. Even though our studio is a ten minutes walk from our flat, we were not allowed to go. For us who use a lot prototyping, we had to work with laptops instead.
When we finally were allowed, we were able to produce and perform our experiments, with masks and all these new rules…