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Alain Destexhe and Luc Foubert June 2016. From spikes to electronic musicSpikiss is a duo made of two CNRS researchers, Alain Destexhe and Luc Foubert, who used experimental recordings of brain activity under the form of spikes, to compose electronic music. The recordings are from different sources, all published. The natural rhythmical activity of neurons is exploited, in particular for inhibitory neurons which are used for the bass and rhythmic sections. The more sparse activity of excitatory neurons is exploited to reveal their melodic capabilities, which are sometimes exacerbated by the choice of instrument. “Wake Beats” – Music from the awake brainThe first “song” that we have made is based on recordings of single neurons in the awake human brain. In particular, we have used recordings where it was possible to formally identify excitatory from inhibitory neurons, and the corresponding spikes were used to drive music. Of course, this was made under certain arbitrary rules to make the music enjoyable! To see how we have done this, please consult the page Composing music from awake neuronal activity, where we have explained it step by step. To listen to this song, please click on As explained in the associated page Composing music from awake neuronal activity, the principle is that the timing of the spike is used to trigger a given sound. This is done in such a way that each neuron has his own, private sound. This sound can be a bass, a percussion, or something more melodic such as bells, xylophone, etc. The inhibitory (“fast spiking”) neurons are generally more rhythmic and can be used to drive the bass and drum sections. The excitatory (“regular spiking”) neurons fire more sparsely and are more appropriate for the melodic sections. In the first part of the song (first minute), the activity of the different neurons is strictly respected, as well as the respective timing of the spikes of the different cells. However, in the second part (starting after the first minute), we have followed a different strategy. We have selected, from the neuronal activity, periods where the activity of the neurons was particularly rhythmic and interesting (based on totally arbitrary criteria!). We have isolated these periods, defining “loops” that can be played several times and in any order. This was done for the different sections, such as the bass and rhythmic activity, as well as for the melodic activity. In addition, we have used more sophisticated sounds from analog and/or digital synthesizers. So in this second part, the respective timings of one cell against another were not always respected, but all the music comes from neuronal activity. This illustrates the power of neuronal activity to generate music. Neurons follow collective dynamics, and have correlations with each-other, and fire together within an ensemble activity which is complex, but not random. Neurons also display marked rhythmic properties, especially for inhibitory neurons which naturally form rhythmic and bass sections. Note that i this example, all neurons considered were simultaneously recorded by a system of 100 micro-electrodes, and the activity was slowed down by about 30%. “Slow Waves” – Music from the sleeping brainThis song was composed from neurons recorded in humans, during slow-wave sleep. As above, the inhibitory neurons form the rhythmic sections, while excitatory neurons drive the melodic parts. Unlike wakefulness, the activity consists of “Up” and “Down” states, where the neurons oscillate slowly between active and silent periods. We have exploited these dynamics and used slow sound envelopes to incarnate the slow waves of sleep. To listen to this song, please click on In the first seconds of the song, one can hear very well the “Up/Down” states typical of sleep, because the bass fires in intermittency, so do all neurons. The slow sounds were driven by excitatory neurons. In the second part of the song, we have used two versions of the slow envelopes (“Woo-Woo”), with major and minor tones, then back to major. The third part (second half of the song), used further slow sounds, mixed with neuronal activities. Note that here, there were no “loops”, the respective timings of the different neurons was strictly respected. See details in the the associated page Music from neuronal activity during slow-wave sleep. “REMiniscence” – Music from the dreaming brainThis third song was composed from neurons recorded in humans, during paradoxical sleep, also called “rapid eye movement sleep” or “REM sleep”. The REM activity is very similar to wakefulness (see below), but we wanted to make it sound a bit different. So we have emphasized the rhythmic sections, still made from inhibitory neurons, and use the excitatory neurons to drive melodic instruments like bells, or sounds that evoke the strangeness of dreams. To listen to this song, please click on In the first part of the song (fist 2:30 minutes), the rhythmic section made by inhibitory neurons is emphasized, together with the melodic section made by excitatory neurons (bells, and voices). In the second part of the song (up to 3:25 minutes), the rhythmic section is now accompanied with bells and a drumkit to form a particularly rhythmic ensemble. In the third part, excitatory neurons drive a synthesizer, along with slower sounds and voices which illustrate the strangeness of dreams. The timing between the different neurons was in general respected all through the song. See details in the the associated page Music from neuronal activity during REM sleep. Jazzy music from different brain statesWe have also generated music for different brain states, in the same conditions, so that they can be compared. We used a more “Jazzy” style for this music. As above, the bass and rythmic sections are given by inhibitory neurons, while the melodic section is from excitatory neurons. The three mp3 were generated from the same human subject. One can hear very well that slow-wave sleep is different than the waking state, and has “pauses” of activity (Up/Down states). However, during paradoxical sleep (where most dreams occur), the activity is more similar to that during wakefulness. PublicationsAlain Destexhe and Luc Foubert. Composing music from neuronal activity – The Spikiss Project. In: Exploring Transdisciplinarity in Art and Sciences, Edited by Kapoula, Z., Volle, E., Renoult, J. and Andreatta, M. Springer, New York, pp. 237-253, 2018. Copyright note: We decided to distribute this music freely, under the protection of a Creative Commons Licence “share alike non commercial” (see below). This means that you are welcome to share and edit the present work, under the condition that you give us proper acknowledgment, and also distribute it freely (and give us a copy!). No commercial application please, unless we have an agreement. The official licence information is pasted below:
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. You are free to copy, distribute, display, and perform the work, as well to make derivatives based on this work, but under conditions that (1) the authors are acknowledged, (2) that no commercial use is made, and (3) that the same “Share Alike” licence is given to any use ofthis work. |
