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Alain Destexhe and Luc Foubert June 2016. In the present page, we explain how we have translated human brain activity into music, for recordings made while the subject was sleeping, in the deep “slow-wave sleep” phase. This corresponds to the song “SlowWaves” Excitatory neuronal activity during slow-wave sleepExcitatory neuronal activity during slow-wave sleepThe principal difficulty with sleep recordings, is that unlike during wakefulness, the neurons’ activities are not sustained, but there are many “pauses”. These pauses are called “down states” and they occur during the slow waves produced by the brain during sleep. An example of this activity is depicted in the following raster:
To listen to that example, click on “Sleeping Bells”. One can hear very well the intermittent character of the neuronal spikes (compare with the similar sound during wakefulness, “Neuronal Bells”). Even if this intermittency may seem problematic at first sight, it can be exploited to obtain nice musical effects. For instance, one can play the excitatory cells above to a slow sound. To listen to that example, click on “Sleeping Waves”. This gives a clear impression of slow “waves”, and indeed they are entirely generated by the neuronal activity of a sleeping subject! We can also use sounds intermediate between fast and slow, which allow us to better hear the melody played by neurons. To listen to that example, click on “Sleeping Mid-Waves”. These are all generated from the same set of excitatory neurons. Activity of inhibitory neurons during slow-wave sleepThe intermittent character of neuronal discharges during sleep also applies to inhibitory cells. For example, pooling together 4 inhibitory cells (chosen for their rhythmicity), gives the following raster:
To listen to these cells, played on a bass, click on “Sleeping Bass”, or played on a drum kick: “Sleeping Kick”. In this example, one can clearly hear that the intermittent character is also present in inhibitory cells, but it does not alter their rhythmic capabilities. As above for excitatory cells, one can also use inhibitory neurons to drive slow sounds. For example, one can take a subset of 5 inhibitory neurons, corresponding to the raster:
To play those cells on the same slow “Woo-Woo” sound considered in Wake Beats, click on “Sleeping Major-Woo”. The same can also be done for a different subset of inhibitory neurons, corresponding to the raster:
In the latter case, however, the neurons were mapped to a minor scale. To play those cells on the “Woo-Woo” sound, click on “Sleeping Minor-Woo”. Here again, one can hear very well the intermittent character of the neuronal discharges during sleep. Assembling it all togetherLet us now listen to the full song, where the first 2 minutes were made from the sounds described above: By listening to this song, one can clearly hear that the intermittent character of neuronal discharges is well coordinated between cells. This coordination makes the music coherent because all sounds are modulated by the same envelope, this envelope corresponds to the “slow waves” of sleep, which we hear musically. Similar to the Wake Beats song, the activity of the different neurons is strictly respected, as well as the respective timing of the spikes of the different cells, but here for the whole duration of the song. In the last part of the song (after the second minute), different slow sounds were used to further augment the impression of “slow waves”. Here again, all the music comes from neuronal activity. 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. www.spikiss.org(available soon…) 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. |
