The Mutual Wave Machine

Welcome! On this page you can explore the research findings from the Mutual Wave Machine, a “crowd-sourcing” neuroscience experiment: scientists asked the general audience to help them understand what happens in our brains when we interact face-to-face with another person. If you were one of those participants: *THANK YOU!*

What can you find here?

  • The interactive map shows where the Mutual Wave Machine has traveled and how many people have participated as of May 2019
  • The results section summarizes the findings and allows you to explore graphs
  • Hyperlinks in the text lead you to elaborations and explanations, as well as related research
  • Interested in exploring the data yourself? All the datasets will live here
  • Last but not least, don’t forget to check out the credits for our fantastic team

What is the Mutual Wave Machine?

What does it mean to be ‘on the same wavelength’ with another person? When you feel connected to another person, are your brainwaves literally ‘in sync’? The Mutual Wave Machine--a brain experiment meets interactive art installation--uses a crowd-sourcing neuroscience approach to answer this question: In collaboration with the general public, researchers explore what makes people ‘click’. Thousands of museum and festival visitors have worn EEG headsets to record their brainwaves while they interacted face-to-face with a stranger or loved one for 10 minutes. Participants sit inside the Mutual Wave Machine, immersed in a real-time reflection (neurofeedback, see below) of their ongoing brainwave synchrony.

The Mutual Wave Machine is a collaborative project between the general public, the art/science collective DIKKER + OOSTRIK (Matthias Oostrik and Suzanne Dikker), researchers (most notably Georgios Michalareas, who led the synchrony analyses), artists (e.g., Peter Burr), our amazing producers Danielle Boelling and Dana Bevilacqua, and several organizations (e.g., NWO). Photographs included here were taken by Talia Herman, Sandra Kaas, and Lexus Hybrid Art. [See full list of credits]

In 2016, The Mutual Wave Machine won the Art of Neuroscience Award. For a review of synchrony-based art/science work, see this chapter.

Brains in sync during real-world social interactions

More about brain synchrony feedback

Who participated?

Nearly 5000 people have participated in the Mutual Wave Machine thus far, and thousands more have seen the experiment in action. Scroll over the map to get basic information about each exhibition site.

Results

Expand the section below to explore the results. If you were a participant, you and your “brainwave partner” may be one of the dots on the graphs. The x-axis always reflects brain synchrony (normalized values). The y-axes are labeled with the corresponding questionnaire responses.

How does interacting with each other affect your mood and closeness?

Participants filled out a few questionnaires both before and after participating. For example, the Inclusion of the Other in the Self Scale measures how close people feel to each other, the PANAS-X measures your mood, and the Interpersonal Reactivity Index measures how you react in different social situations.

Social interaction and mood

What can you do to make your brainwaves sync up?

Participants were asked to indicate which strategy they used to connect to each other and whether they thought it worked to sync up their brainwaves. People tried many strategies, which largely fell into the following categories: (1) doing something together (2) thinking about the same thing (3) eye contact. Which of these strategies do you think made brain synchrony go up?

Brain synchrony and connecting strategies

Does brain synchrony relate to your social bond?

We also asked all participants to indicate how long they had known each other (theirRelationship Duration) and how close they felt to each other (Social Closeness).

Brain synchrony & relationship duration

Social closeness & brain synchrony

Does brain synchrony relate to personality and focus?

Next, we asked whether people’s social personality traits (empathy), and mental states (focus) predicted their brain synchrony.

Empathy & brain synchrony

focus & brain synchrony

Methods

Tools

To collect the EEG data, we used the EMOTIV EPOC an EEG headset with 14 electrodes. We built software that allowed us to record data from multiple headsets onto a single computer, and we then used openframeworks to analyze and visualize brainwave synchrony in real-time.

We are currently testing whether interpretable data during social interactions can also be acquired with the Muse, a headset with 4 electrodes. We built an iOS app to collect data from the Muse and then transmit it to a mother computer using Lab Streaming Layer. We then use python to compute brainwave synchrony, which is visualized with openframeworks. This is a collaborative effort with David Medine, Jean Jacques Warmerdam, Laura Gwilliams, and Phoebe Chen. The protocol will be posted to the BCI plus site.

We worked with Peter Burr on the aesthetics of the visuals.

Procedure

At all the sites where data collection has taken place so far (see interactive map), the procedure consists of the following steps:

STEP 1

Match participants, setup EEG headsets

If you volunteer to participate, you are first matched with a ‘brainwave partner’. This can be someone you know or a complete stranger. You are each fitted with an EEG headset (EMOTIV in most cases, unless you participated at the Espacio Fundacion Telefonica in Madrid, where we used the Muse headset instead) and you are shown your own brainwaves on a tablet or computer. You can clearly see why researchers usually ask people to sit still: the signal goes all over the place when you move (see EEG for more on this).

STEP 2

Complete questionnaire

Right before entering the Mutual Wave Machine, you both fill out a short questionnaire about your relationship, how you feel about each other, how you tend to behave in specific social situations, and your current mood. The questions vary by location.

STEP 3

Pairs sit in the Mutual Wave Machine

Then you are led into the Mutual Wave Machine. For 7-10 minutes, you will sit opposite your brainwave partner and you will see and hear direct reflections of your brainwave synchrony: more light means more synchrony, and less light means less synchrony.

STEP 4

Complete questionnaire again

After the experience, you will again fill out a short questionnaire.

Analysis

Georgios Michalareas wrote a series of MATLAB scripts that clean and analyze data using the fieldtrip toolbox.

  • First, we discarded datasets with too many motion artifacts or other recording problems.
  • Then, we cleaned the remaining datasets: this meant removing stretches of data with a lot of noise and electrodes that didn’t have a good enough connection to the scalp to record brainwaves properly.
  • The data was then filtered into different brainwave frequencies.
  • Then, for each frequency, we computed a few different types of brainwave synchrony. These types largely fall into two different categories: (1) do pairs show similar fluctuations in their brain states? (2) do pairs’ brainwaves show the same shape?
  • Finally, brainwave synchrony was compared between groups (for example the feedback vs. no feedback groups) and as a function of participants’ responses to the questionnaire questions (for example, empathy).

Phoebe Chen also analyzed data using mne for python.

Releated artworks

By DIKKER + OOSTRIK

By others

Related research

  • Brainwaves sync up in the classroom: original article here and here | selected press coverage here, here, and here.
  • Friends show the same brain activity: original article here | selected press coverage here
  • Brainwave synchrony during pain perception: original article here | layman’s blog here and here

Credits

Matthias Oostrik, Suzanne Dikker, Georgios Michalareas, Peter Burr, Danielle Boelling, Melda Kahraman, Dana Bevilacqua, Marina Abramovic, Amalia Serafimaki, Matthew Patterson-Curry, Lauren Silbert, Pandelis Diamantides, Marijn Struiksma, Phoebe Chen, Laura Noejovich, David Medine, Bogomir Doringer, Olof van Winden, Laura Gwilliams, Jean Jacques Warmerdam, David Poeppel, Annita Apostolaki , Shaista Dhanesar , Imke Kruitwagen , Eletta Daemen , Orsa Rebouskou , Stella Papazisi , Aspa Papazisi , Karlijn Blommers , Sascha Couvee , Ella Bosch , Jorik Geutjes , Irene Navarro , Alba Ortiz , Marta Regidor , Sandra Marquez , Belén Carrillo , Luna Miranda , Ester Abad , África Martín , Estefanía Granados , Iratxe de la Huerta , Isabel Rojo , Keumbee Lee , Patricia Plaza , Noelia Gómez , Brais Alen , and all the local volunteers , Netherlands Organisation for Scientific Research, VENI grant #275-89-018, EMOTIV, Muse, Universiteit Utrecht, TodaysArt, Lexus Hybrid Art, Marina Abramovic Institute, Pioneer Works, 3LD Art & Technology Center, NEON, Fundacion Telefonica, Lowlands Festival (Lowlands Science), Nemo Science Center, EYE Filmmuseum, Benaki Art Museum, Creative Industries Fund NL, Nationale Wetenschapsagenda, De Hersenstichting, Stichting Niemeijer Fonds, FORMS Festival, Silicon Valley Contemporary