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Brain Products Press Release October 2011, Volume 40

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IN THE FOCUS

Brains Swinging in Concert by Prof. Dr. Ulman Lindenberger, Dr. Viktor Müller and Johanna Sänger (Max Planck institute for Human Development) Investigate the Interbrain

Synchronization of a Guitar Quartet and its Audience

Motivated by their curiosity about the brain activity of two individuals

who are engaged in a task requiring mutual coordination, in 2006

Ulman Lindenberger and Viktor Müller invited some guitar duettists

into their lab for the first time and made simultaneous EEG recordings

of the musicians’ brains as they interacted with each other1.

Five years later, after focusing extensively on the phenomena of brain

synchronization and brain connectivity in these dyads, Lindenberger,

Müller and their PhD student Johanna Sänger wanted to delve

deeper still: to what extent were their earlier findings applicable with

an ensemble of four guitarists who were not playing short melodies

in the setting of a carefully structured laboratory-based design, but

making music in a quasi-natural setting?

Accordingly, they embarked on a longitudinal case study which in

the first instance followed the activities of the Cuarteto Apasionado,

a professional Berlin-based guitar quartet, over the course of a

five-month period of rehearsals. At intervals spaced approximately

six weeks apart, the quartet held four rehearsal sessions at the

premises of the Max Planck Institute during which they worked on

Astor Piazolla’s “Libertango” and “Comme un Tango” by Patrick Roux.

In their study, the researchers wanted to investigate what kinds

of synchronization and connectivity patterns could be found in

four people when they were playing a complex piece of music.

Would their brains show a certain pattern of connectedness and

disconnectedness that corresponded to their musical roles? Or,

depending on which voice each of the guitarists played, would these

patterns change over the course of the rehearsal period (during

which their behavioral coordination was being perfected), and would

they whatever brain synchronization and connectivity were found be

attributable to the musical content that required the greatest effort

of coordination?

As a crowning finale to their involvement with the quartet,

Lindenberger, Müller and Sänger arranged a so-called Lab Concert

in which the Cuarteto Apasionado appeared before an audience

made up of members of the public. The musicians played not only

the two pieces they had been working on during the rehearsals in the

lab, but a one-hour program of Latin-American guitar music which

they had not previously rehearsed. As in the rehearsal sessions,

each of the guitarists was assessed using a 32-electrode actiCAP, an

electrocardiogram (ECG), a respiration belt and acceleration sensors

on both hands. Each of the guitars was recorded on a separate audio

channel, as well as the player’s physiological measurements, and

the sound was also recorded in a video capture of the event that was

synchronized with the other recordings using the BrainVision Video

Recorder.

The concert was held partly in order to check whether the effects

recorded in the rehearsal data would be different during a concert

at which an audience drawn from the public was present. As

the pressure to be perfectly coordinated on such an occasion is

especially high, the corresponding brain mechanisms might be more

strongly apparent. Or does an audience’s presence interfere with

the functional brain network established within the quartet when its

members are playing together? And what actually happens within

the listeners, as well as between the listeners and the musicians?

In order to find out, four listeners were recruited as participants. Two

of them were semi-professional guitarists themselves and so were

able to follow the concert with a degree of sophistication, while

the other two were musically naive. They were wired up the same

as the musicians (minus acceleration sensors, as the listeners were

not supposed to move during the concert); the testing accordingly

resulted in 256 EEG channels and 28 bipolar channels (ECG and

Picture 1: Guitar quartet

Picture 2: BrainVision Video Recorder based recordings

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Brain Products Press Release October 2011, Volume 40

respiration for both musicians and listeners, movement and audio

captures for the quartet only). It was possible to record all the

bipolar channels and the EEG channels of six of the subjects on a

single computer, but the EEG amplifier for two of the listeners had

to be connected to a second machine. Thanks to Brain Products, the

research team was able to use a special set-up for this in the form of

the BrainVision MOVE wireless system, which provided connectivity

between the electrodes and amplifiers.

The researchers are now excited to see whether they will be able to

detect differential effects among the various listeners: specific effects

might be anticipated to occur in the ‘professional’ listeners, as they

were able to predict the playing of the quartet due to their musical

knowledge, while the effects observed for the musicians versus the

naive listeners might be expected to be opposite in direction. The

two parties of the concert scene will be distinguishable, but will

there also turn out to be a common network, and in what way will it

have been shaped by the music being played?

These are some of the questions that the research team from

Berlin’s Max Planck Institute for Human Development will examine.

It can be guaranteed that this unique investigation, made possible

by the assistance provided by Brain Products, will contribute some

interesting insights into the neural events that take place in a social

situation2.

References:

1 Lindenberger, U., Li, S-C., Gruber, W., & Müller, V. (2009). Brains Swinging in Concert: Cortical Phase Synchronization While Playing Guitar. BMC Neuroscience, 10(22).

2 Sänger, J., Lindenberger, U., & Müller, V. (in press). Interactive Brains, Social Minds. Communicative and Integrative Biology. Picture 3: Wireless recordings with BrainVision MOVE

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