Music for Brainwaves: Embodiment of Sound, Space and EEG Data

The essence and inspiration of Music for Brainwaves came from Alvin Lucier’s iconic piece Music for Solo Performer. Neurofeedback and physiological data (EEG) are explored as components in the relationship among sound, space, and the body of the performer. Although EEG registrations have been well explored for sound installations, music performances, and music cognition, relatively little is as yet known of the application of physiological data (EEG) within a system including the projection of sound into an architectural space, and the consequent embodiment, as inner experience, by a performer.


Introduction
Music for Brainwaves focuses on sound, space, physiological data (EEG), and perception. From a compositional point of view and in contrast to Lucier's Music for Solo Performer, where EEG triggers a physical movement on percussion instrument, Music for Brainwaves explores a sound continuum based indeed on EEG data, but generated by an algorithm. The sound continuum is based on Xenakis's algorithm Gendy3 originally adapted by Nick Collins for the SuperCollider software and then ported to the Max/Msp software by Stephen Lumenta (Di Nunzio, 2013).
The algorithm produces a chaotic continuous sound that is, metaphorically and aesthetically, intended to reflect what the sound of the firing neurons might be.
Music for Brainwaves is based on an interface employed in collecting physiological data from a performer. Then, the algorithm processes the collected data, and the consequent generated sound is projected in a (resonant) performance space; the result is heard by the performer, and thus included in a neurofeedback loop. In section 1, the definition of hyperbiological space will be introduced, and also how the performer primarily perceives it. The section moves towards the definition of EEG, Brain Computer Interfaces (BCI), Brain Computer Musical Interfaces (BCMI), and neurofeedback. Section 2 introduces the origin of the piece influenced by

Hyperbiological Space
The hyperbiological space is an augmented peripersonal space, which is defined as 'the space immediately surrounding our bodies ' (Rizzolatti et al., in Holmes and Spence, 2004: 94) and proposed as a conceptual relationship of space, sound, body and physiological data (EEG). The relationship between the performer/machine computer network delineates the hyperbiological space, where physiological data processed by computer are determined and sent as sonic information to the performance space where it is, in turn, received and processed by the performer. The performer's reception of the sound closes the loop, causing the corresponding modulation of physiology known as neurofeedback. Vernon proposes neurofeedback as: A sophisticated form of biofeedback based on specific aspects of cortical activity. It requires the individual to learn to modify some aspect of his/ her cortical activity. This may include learning to change the amplitude, frequency and/or coherence of distinct electrophysiological components of one's own brain (2005: 347). Accordingly, considerations in higher-dimensional spaces are not discussed here, nor are mathematical models proposed. However research made in such areas is useful in understanding abstracted dimensions related to a space where biological information is included. In particular Lewis Carroll's ideas about higher-dimensional spaces emerges from the great nineteenth-century German mathematician Georg Bernhard Riemann, who demonstrated that these universes obey to their own inner logic (Kiku, 1995: 22, 23). The space sensed through neurofeedback by the performer includes the idea of the 'higher-dimensional space'. Such sensed space appears when the performer hears, in a very resonant space, the sonic result created by his own EEG. The hyperbiological space is a complex dynamic subjective internal and external space in a closed loop provided by neurofeedback, and thus the cognitivearchitectural space. Roy Ascott proposes the term ' cyberception' in explaining the relationship between our selves and the mediated world, and how we are augmented: Cyberception involves a convergence of conceptual and perceptual processes in which the connectivity of telematic networks plays a formative role (…) It redefines our individual body, just as it connects all our bodies into a planetary whole (2003: 320, 321).
Although the experience of augmentation of the self in Music for Brainwaves does not involve the telematic mediation through the Internet as proposed by Ascott, a network indeed exists in the relationship among body, physiological data, sound, and space through neurofeedback.

EEG
The discovery of human EEG (Electroencephalogram) measurements, and in particular the alpha wave, were first discovered by the German neurologist Hans Berger in 1924(Millet, 2001. The procedure of measurement of the electrical activity of the firing neurons in the brain is known as EEG. The data is then filtered to obtain different frequencies, which have different functions. Without proper processing and filtering, EEG data is essentially random data.

BCI (Brain-Computer Interfaces)
Brain Computer Interfaces (BCI) monitor the activity of the brain measurements (EEG). In the last decade it has improved as an extension of the body in order to control computers, prostheses or wheelchairs. BCI appeared in many other domains than neuroscience and medical fields such as video games, media art and music, among other fields. The next decade could unlock other opportunities, according to Lance et al.: Based on advances in sensor technologies, analysis algorithms, artificial intelligence, multi-aspect sensing of the brain, behaviour, and environment through pervasive technologies, and computing algorithms will be capable of collecting and analysing brain data for extended time periods and are expected to become prevalent in many aspects of daily life (2012: 13).

BCMI (Brain-Computer Music Interfacing System)
As an extension of the BCI the BCMI is an interface that is specifically directed toward the production of music. The idea is directly inspired by Alvin Lucier's piece Music for Solo Performer, and has since then evolved according to the power of the computers and the availability of affordable devices (Miranda, 2014: 1-27). For the actual work, the IBVA (Interactive Brainwaves Analyser System) BCI was used. The IBVA, developed by Masahiro Kahata, was one of the earliest affordable systems. It filters the raw data from the EEG into four frequencies named alpha, beta, delta and theta ranging from 2 Hz to 45 Hz (Miranda, 2014: 202). Music for Brainwaves focuses on the alpha frequency, as in the Alvin Lucier work's Music for Solo Performer.

Neurofeedback
By watching and listening to real-time multimedia representations of its own electrical activity (EEG), the brain can improve its functionality and even its structure (Budzynski et al., 2009: xxi).

Background
The major influence of Music for Brainwaves came from Alvin Lucier's piece, Music for Solo Performer. The points of convergence rely on the idea of control and energy data (EEG), present as a main component in Music for Brainwaves. The control of the body by the meditative state includes the energy data transferred to an algorithm, as proposed by Lucier: Dewan described to me this phenomenon that had to do with visualization, that by putting yourself in a non-visual state, it would be called a meditative state now, you could release the potential of the alpha that is in your head.
It's a very small amount, but it would become perceptible, at least to an amplifier (…) Actually, it doesn't sound like anything because it's ten hertz and below audibility; it isn't a sound idea, it's a control of energy idea (1995: 48, 50).
During the same period, composers and artists were collaborating with engineers to integrate new technology and thus discover new tools for new forms of music and art. A noteworthy example is a series of performances in New York in 1966 called 9 Evenings: Art, Theatre and Engineering. These events were developed by artists and engineers and ' endeavoured to reassess a legendary series of ten experimental performances that were presented at New York's 69th Regiment Armory on East 25th Street in October, 1966' (Garwood, 2007: 36). Among others there were the performances of Cage's Variations VII: Cage was performing an unscored work for the first time, attempting a live broadcast of all the sounds in the world at once. Variations VII, like other Cage compositions, departed from art-making as a purely pictorial process and moved it toward the spatial, experiential, and conceptual. This particular work highlighted the soup of invisible frequencies in the realm of immediate experience (Garwood, 2007: 40).
Music for Brainwaves relates to Cage's work Variations VII through the 'soup of invisible frequencies in the realm of immediate experience' described by Garwood, since the performance includes invisible frequencies as EEG from the body performer into the performance space. Consequently, Music for Brainwaves attempts to bring brainwaves into the musical realm, which includes the notion of making an invisible activity perceptible. David Rosenboom, one of the closest allied with brainwave music, and Richard Teitelbaum with his pieces Organ Music and In Tune of 1968 (Branden, 2011: 132) and, later, Pauline Oliveros explored EEG for musical purposes Inevitably, artists with an experimental bent would come to apply this -and subsequent developments in brain science -to both artistic production and research in artistic perception (1990: 48). Improvement of technology, and subsequent developments in brain science, leads to more affordable devices; advances in neuroscience research from the last decade when it is approached as a change in the sonic cloud with artefacts in the sound, it could lead to dedication rather than distraction, because the attention of the audience is directed towards few movements and events. During the development phase of the project, trials included other performers, such as a cellist and a dancer.
The former was very convincing in term of musical interactions and gestural presence towards the audience; the latter formally provided an interesting perspective, given the contrast between a moving dancer and an immobile EEG performer. Both ideas, and their visual contributions, were, however, abandoned in order to concentrate on a purely (hyperbiological) spatial relation among an architectural resonant space, sound, and physiological data (EEG) from the performer.

Composition
Music for Brainwaves is based on the Gendy3 algorithm from Iannis Xenakis, and implanted into the software Max/Msp. The performance relies on four different predefined parameters of Gendy3, which structure the movements of the composition.
The movements last three minutes each.

Performance
Actions for the performance are pre-determined yet improvised in length, according to the performance space and the audience. Improvisation gives a more flexible range of possibilities; the actions (i.e. sitting, lying on the floor, and reading a text) provide: • Different sonic gestures; • Different states of consciousness, however limited by the duration of the performance.
The algorithm is based on aleatory procedures and thus the results are not always predictable; they are mainly changes in the frequency, amplitude, and timbre of sound. The differences in brainwaves activity modulate the sonic cloud from the • 'The immediate physical and emotional experience of the endo-movement, so to speak, the movements inside the body'; • 'The hypnagogic trance states one might experience in a "ritualistic or liturgical" context'; • 'The performer's own immediate experience of multiple, simultaneous, fluid "phantoms" of self or of the body's signs in motion: the immediate sensations of mediations'.

Xenakis's Gendy3 Algorithm
The choice of Gendy3 algorithm is based on the quest for a sonic aesthetic that develops a chaotic continuum, metaphorically intended to reflect the activity of firing neurons. Also, the idea of the performance relies mostly on the improvisation of bodily pre-defined gestures (e.g. put on the EEG device and start the algorithm; sit for as long as you feel it necessary; lie on the floor, for as long as you feel it necessary; sit again for as long as you feel it necessary; take a text and read it silently; end the performance or start again from the beginning if you feel it necessary), which move according to pre-defined parameters derived from Gendy3. In these pre-defined parameters, the responsibility for generating numbers inside the algorithm is left to the computer: Gendy makes sound by repeating an initial waveform and then distorting that waveform in time and amplitude. Thus the synthesis algorithm computes each new waveform by applying stochastic variations to the previous waveform (Roads, 1996: 342). In this sense, 'filling sonic space with sound material and structuring this space are accomplished with similar means' has a strong metaphorical connotation with Music for Brainwaves: filling the physical performance space by using the sounds emerging from Gendy3 as a strong sonic impulse into the resonant space, to trigger the hyperbiological space, which in turn leads to neurofeedback.

Ex-NSA Teufelsberg Listening Radome, Berlin
During the research process, different architectural configurations (e.g. apartment, artist's atelier, theatre, and university laboratories) were tested, but none of them was resonant enough to sense the hyperbiological space, meaning to perceive the relation between, energy data (EEG), sound and space through the whole body as neurofeedback.
They sounded ' dry'; a specific element was lacking from the neurofeedback,  In addition, those particular resonant frequencies are found also in other sacred locations around the world:

Forcucci: Music for Brainwaves 90
Special sound is associated with the sacred: from prehistoric caves in France and Spain to musical stone temples in India; from protected Aztec codexes in Mexico to Eleusinian Mysteries and sanctuaries in Greece to sacred Elamite valleys in Iran. It was human nature to isolate these hyper-acoustic places from mundane daily life and to place high importance to them because abnormal sound behavior implied a divine presence (2014).
Cook, Pajot and Leuchter suggest that further research should be conducted in order better to understand the links between resonance and emotional processing: Previous archaeoacoustic investigations of prehistoric, megalithic structures have identified acoustic resonances at frequencies of 95-120 Hz, particularly near 110-12 Hz, all representing pitches in the human vocal range (…) We evaluated the possibility that tones at these frequencies might specifically affect regional brain activity (…) These intriguing pilot findings suggest that the acoustic properties of ancient structures may influence human brain function, and suggest that a wider study of these interactions should be undertaken (2008: 95).
Such pilot studies are of interest for future investigation in order to explore potential relationships between resonances, frequencies, and neurofeedback.

Achievement, Conclusions
The development of Music for Brainwaves as a performance explored issues emerging from a performer's body emitting physiological data as EEG, transformed into sound, sent into a resonant space and received back as neurofeedback by the same performer. The process leads to the term hyperbiological space, which relates to an augmented peripersonal space (by physiological data through sound in space) and the impression of sensing the relation of sound and space by the performer in the first instance, since 'the composer, wired-up in various ways, would become the performer of and primary listener to the sounds produced' (Branden, 2011: 132).
The sensed space appeared in particular when sounds were sent into the resonant space of the ex-NSA Teufelsberg listening station; there was a clear impression of the embodiment of the sensed space. It has been shown that such experiences with resonating space existed from at least the Neolithic period and lead 'to isolat[ing] these hyper-acoustic places from mundane daily life and to attribute high importance to them because abnormal sound behaviour implied a divine presence' (Eneix, 2014). Further research must be accented in very resonant spaces, since the most active sensation of neurofeedback, at least for the performer, is experienced in such spaces. How to explore inner experience of sensing and to transfer it to the audience?

Competing Interests
The author has no competing interests to declare.

Author Information
Luca Forcucci is an awarded artist and scholar based in Berlin. He focuses on the perceptive properties of sound and space, subjectivity and consciousness. The field of possibilities of the experience is explored as the artwork. A major influence is the late composer Pauline Oliveros and her concept of deep listening.