The Neuroscience behind dancing
Dancing with someone can give a magical feeling of close connection. When we listen to music, our brain gets a little surprised by rhythms and melodies, and it makes us move, often with others. We use all our senses -sight, sound and even touch- to communicate with our dance partner to reach the highest peaks of synchronization. However, people with mental health conditions may interpret these complex social signals differently. This can make experiences like dancing—where reading cues is essential—more challenging. Four IIT researchers, based in Genova and Rome, explain what happens in our body and brains when we dance with someone and what it is like to get conflicting social information. You want to experience this for yourself? Visit their interactive exhibit, Dancing to someone else’s beat, at the Festival della Scienza in Genova from October 24th till November 3rd. This exhibit shows that dancing with someone is more than just moving to music, but it is a complex sensory-driven connection between people.
You dance to the beat of the music and the beat of your partner
Synchronized movements, such as dancing in a group, strengthen bonds and encourage cooperation – key ingredients for social bonding. But does this synchronization only happen because of the music, or are our dance moves influenced by the people around us? Félix Bigand (postdoctoral researcher at the Neuroscience of Perception and Action lab at the IIT in Rome) set out to explore this question. In his recent paper, he created a ‘silent disco’ experiment, where people danced together. In a clever twist, dancing partners would sometimes listen to music at a different tempo or would not be able to see their partner. ‘We were most interested in what happens when you see another person, but you hear a different rhythm. Would you synchronize with your own beat or with theirs? We found that you don’t need to choose! Some movements synchronize with the music, while others follow the beat of the other person totally independently’, Félix explained. He found that synchrony of head movements, like nodding, were typically driven by the music. Surprisingly, other motions, such as swaying sideways or waving hands, were more often synchronized with the dance partner. This suggests that there are indeed movements that have a social function. A third category, bouncing (moving up and down), seemed to be influenced by both the music and the partner. ‘Bouncing could serve as a central cue for synchronization’, Félix suggested. ‘I hear a beat, I want us to synchronize, so I imitate you, but if you bring me to another beat, it creates a tension, I want them to be matched.’
To delve deeper into what was happening in the brain, Félix is also using EEG (electroencephalography), a technique to measure electrical brain activity using a kind of swim cap with electrodes that then attach on the scalp. This research is still ongoing but interestingly, it already seems that bouncing generates a particularly strong neuronal response. “This could mean we’re paying special attention to bouncing,” Félix added. This central role of bounce into rhythmic coordination could originate from the very beginning of our lives. ‘Bounce is also what a baby experiences when the mother is walking, so it is one of our first experiences of rhythmic movement.’
The musical brain is full of surprises
Before we start bouncing our head, music needs to go from the source of sound, through the ears up to the brain. What makes us love certain songs? Roberta Bianco (Marie Skłodowska-Curie fellow at the Neuroscience of Perception and Action lab at the IIT in Rome) is fascinated by how the brain reacts when people listen to music they like. ‘Music is composed of rhythm and melody. When you are listening to a song, your brain automatically guesses which note comes next and when the beat should happen’, she explains. Music plays with these expectations. Often it follows what your brain predicted, but it can also be surprising. When the music is too regular, it is boring. Though, if it is too random our brain cannot follow it. There is a sweet spot in the middle where we experience pleasure and the desire to dance the most. ‘This might explain the power of groove’, according to Roberta. There is a bit of change in the beat called syncopation. Syncopation happens when the beat is placed between the regular beats. It’s like clapping off the beat, making the music more unexpected and exciting.
Using EEG to measure brain activity, Roberta studies how the brain responds to music. From this she can measure how surprising a note is in terms of melody and rhythm. In human adults, there is a big change in brain activity when a note is surprising for both melody and rhythm. Roberta’s current work shows that even two-day old babies already track rhythm, but their brains do not track melodic surprise yet. ‘Rhythm seems to be built in, but following a melody might be learned through development and experience,’, Roberta notes. ‘This may be because, in the womb, babies are exposed to biological rhythms, such as walking and their mother’s heartbeat, but high-pitched sounds are filtered. After birth, through infant directed speech and songs, the baby will hear melodies.’ Roberta’s ongoing research now aims to understand how children develop the ability to follow melodies during the first year of life. She wants to know how speech and music exposure shape this skill.
Your brain uses all your senses to move and groove
When dancing with someone, we not only listen to music, but we also see the other’s movements and sometimes use touch to find optimal synchronization. I, Josien Visser (Marie Skłodowska-Curie fellow in the Optical Approaches to Brain Function Lab at the IIT in Genova), study how the brain combines information from all different senses and how this affects behavior. This phenomenon is called multisensory integration. Simple illusions clearly show that your brain indeed combines sight and hearing to understand the other. What you see can even trick what you hear! In an illusion called the McGurk effect (see this video) the auditory and visual inputs conflict: What you hear (for example, ‘ba’) does not match with what you see (lip movements showing ‘ga’). The brain, instead of sticking to just one sense, blends the inputs and creates a new perception (‘da’), showing how deeply connected our senses are. In our exhibit Dancing to someone else’s beat, which will be presented in Genova, you will experience how combining auditory and visual input helps understanding someone else. Usually, the beat of the music aligns with the dance moves of the others. But what happens when the rhythm does not match your visual input? Will you rely more on your eyes or on your ears?
Mental health affect simple interactions such as dancing
Dancing with someone can feel like a joyful, simple activity. But for people with mental health conditions, such as schizophrenia and autism, these interactions can be very challenging. According to Christine Stubbendorf (Marie Skłodowska-Curie fellow in the Genetics of Cognition Lab at the IIT in Genova), social interactions are more difficult than they appear. A happy and surprised face can look very similar. Or what does it mean if someone tells you he is happy, but has a sad expression? This creates a mixed signal which can be difficult to interpret. ‘People with schizophrenia often struggle understanding these cues, making them insecure and social avoidant’, Christine explains. Her research focuses on the medial prefrontal cortex, a brain area involved in making decisions. Interacting with people means making decisions all the time: Have I seen this person before? Is the person happy or sad? In what way should I respond? It is known that in this brain area the baseline activity is lower in schizophrenia patients. Christine investigates how brain activity changes in specific social situations. She hopes that understanding better how the brain functions could lead to more specific treatments, so people with schizophrenia become less avoidant and can be able to be part of society while using less medication. ‘In our exhibit Dancing to someone else’s beat for the Festival della Scienza you can experience what it is like to socially interact with people, while being challenged when you do not have all the information you are used to’. This can give you a firsthand look at how mental health conditions can affect your social life.
*pict cover by Lucrezia Faraggi
**Josien Elizabeth Visser is a Researcher of the IIT Optical Approaches to Brain Function unit
