Ge n e rAl A r t i c l e
Chromatophony
A Potential Application of Living Images
in the Pixel Era
J u p p o yoKoK A w A, noBu hIr o m A Su dA An d KAz u hIr o J o
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Squids can rapidly change their body color using chromatophores that
are controlled by electrical signals transmitted through nerves. The authors
transform a squid’s skin into an audio visualizer called Chromatophony.
This is accomplished by sending an electric tone signal composed as
music to the skin. Although Chromatophony’s appearance is similar to
that of computer-generated images, it is based on a natural phenomenon
with a colorful mosaic display. By comparing chromatophores with
pixels, the authors propose Living Images to expand the potential of
visual expression from the perspective of bioart theory.
Cephalopods such as squids are known to rapidly change
their body color to display patterns for intimidation or cam-
ouflage. Using this phenomenon, we created Chromatophony,
an artwork in which chromatophores, organelles composed
of living cells that allow the squid to change color, are con-
verted into an audio visualizer by electrical stimulation.
In diesem Papier, we use Chromatophony as a means to re-
consider bioart from the perspective of visual art. We report
on the significance of an idea called Living Images in the
practices of bioart, as a means of proposing a critical per-
spective countering the dominance of the unit of the pixel
in contemporary visual display.
We first describe the idea of Living Images and then dis-
cuss the historical background of the pixel to compare digi-
tal images and Living Images. We explain our work and the
significance of Living Images within biomedia art as well as
within contemporary visual culture.
whAT IS The lIvIng ImAge?
We define Living Images simply as aesthetic images gener-
ated from living cells, exemplified in the history of scientific
practices and the recent rise of bioart: from Alexander Flem-
Juppo Yokokawa (Forscher, artist), Art Media Center, Tokyo University of the Arts,
12-8 Ueno Park, Taito-ku, Tokio, Japan. Email: juppotamus@gmail.com.
Nobuhiro Masuda (Forscher), Faculty of Design, Kyushu University, 4-9-1 Shiobaru
Minami-ku, Fukuoka, Japan. Email: masuda@design.kyushu-u.ac.jp.
Kazuhiro Jo (Forscher, artist), Faculty of Design, Kyushu University/YCAM, Kyushu
Universität, 4-9-1 Shiobaru Minami-ku, Fukuoka, Japan. Email: jo@jp.org.
Siehe https://direct.mit.edu/leon/issue/55/3 for supplemental files associated with
this issue.
ing’s microbial paintings [1] to recent trends in bioart through
experimentation with biological networks using slime mold
[2]. Although Chromatophony (Color Plate C) can be placed
within this category, our work notably attempts to embody
the idea of Living Images literally, as we explain below.
The idea of Living Images is derived from the hypothesis,
declared recently in the domains of art history and visual
culture studies, that images are alive [3,4]. Hans Belting, für
Beispiel, is one of the leading theorists of Bild-Anthropolo-
gie, which examines how images have been intertwined with
bodies and media across cultures throughout human history.
According to Belting, mental or physical images are never
fully controlled by humans but rather are nomadic entities
embodied by our bodies and media [5]. From ancient burial
objects to contemporary digital photography, Belting empha-
sizes the functions and vitality of the image independent of
humans that enable it to inhabit the human body and tech-
nological media.
While Belting describes “living images” from an anthro-
pological perspective, we have appropriated this idea and
applied it to bioart. Bioart is a practice of using the knowl-
edge of biology as an artistic medium, or of advancing the
changing nature of life through artistic output [6]. Along
with the rise of bioart, the development of molecular biology
and genetic engineering also continued during the latter half
of the twentieth century. The recent discovery of horizontal
gene transfer [7] and the way viruses and pathogens prolif-
erate overlap with the nomadic images proposed by Belting.
daher, we focus on bioartworks composed of cells or tis-
sues that are literal living images.
We also compare the pixel, the elementary unit of digital
Bilder, context of Living Images. We refer to the studies of
Alexander Galloway [8] in which he detaches the pixel from
its computer context and places it on a historical horizon
with reference to Neo-Impressionist pointillism and eigh-
teenth-century calculators. From this perspective, we evalu-
ate the analogical functions of chromatophores and pixels as
units of living/digital images.
252 LEONARDO, Bd. 55, NEIN. 3, S. 252–257, 2022
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The geneAlogy oF The pIxel And ITS Two
FunCTIonAl ASpeCTS
In 1965, the term pixel appeared in a technical report titled
“Digital Video Processing at JPL” [9], derived from the words
“picture element” and “picture cell.” For a time, it was used
alongside the word pel, also derived from “picture element.”
Gradually, the word pixel came to mean an “element in an
image sensor,” or the smallest unit of a digital image, a light-
emitting element composing a digital display [10].
In contrast to the historiography of this invention, Gal-
loway extended the implications of this term epistemologi-
cally by focusing on its functions. Anfänglich, he noted two
modes of the pixel: the square as the smallest geometric
point and the numerical value as an algebraic number with-
out substance. He then argued that even before the com-
puter, pixels could be found in the technical and aesthetic
practices of the modern era, starting in the eighteenth
Jahrhundert. If we understand the pixel as a small square, es ist
possible to view these geometric points as a descendant
of artistic expressions such as De Stijl, color field paint-
ings and Neo-Impressionist pointillism. Umgekehrt, gegeben
that pixels function as a numerical value, they had been
incorporated by Jacquard looms as well as Nicholas Saun-
derson’s eighteenth-century calculator. Letzteres, a manual
calculator, had a procedural algorithm and mechanism
that involved the interlocking of a grid of pins to facilitate
computations.
Based on these two aspects, Galloway reconsidered the
features of a pixel as a given coordinate or luminance value
that could be processed mathematically: “The pixel is to the
digital image as the frame is to the cinematic image” [11]. In
other words, a single pixel does not make sense unless it is
assembled with other pixels in an image, just as a frame in a
film only has meaning if projected continuously with other
frames. Weiter, pixels divide images spatially, just as frames
divide motion temporally.
Galloway is not the only one to trace the genealogy of
pixels back to film and Neo-Impressionism. Among stud-
ies in aesthetics and art history, Meredith Hoy states in her
book From Point to Pixel, “Pointillism contains enough digi-
tal elements from the beginning to the end of production
to warrant consideration as a digital system, aber es ist nicht
computational” [12]. From this perspective, the little square
pixel can be treated as the descendant of modern paintings,
although they exclude its numerical function.
Before Galloway and Hoy, Sean Cubitt stated in his book
The Cinema Effect that the equivalent of the pixel could
be found in the pointillism of Neo-Impressionists such
as Camille Pissarro, Georges Seurat and Paul Signac, WHO
translated light into pigments. Weiter, Cubitt extended this
relationship to the contemporary products of the Lumière
brothers: the cinematograph and Autochrome [13].
Although the emphasis differs from art history to media
theory, these discussions are significant when examining the
context of Chromatophony, which uses the pigmented colors
that are embedded in the skin of a squid to form a visual
display. To compare the chromatophores constituting Living
Images with the pixels in digital images, we adopted claims
that focus on the visual and spatial as well as the algebraic
and temporal aspects of pixels.
ChromATophoreS AS A pIxel oF lIvIng ImAgeS
Rapid color change in squids is made possible by a set of or-
ganelles called chromatophores, comprising multiple muscle
and nerve cells, and pigment-containing pouches [14]. Jede
chromatophore contains only one type of pigment; während
color changes, only the pouches contract or expand, chang-
ing them in size [15]. This makes chromatophores an elemen-
tary unit of Living Images just as the pixel is in digital images
as some biologists implied [16].
These “dots” come together to form larger patterns, whose
density of colors evokes the impression of pointillist paint-
ings of the Neo-Impressionists; zoologist Andrew Parker
compares the way these pigment vesicles come together to
create colorful images to pixels on a screen [17].
This analogy is not confined to visual appearance but
extends to function. Each squid has chromatophores with
unique relative positional relationships [18]. Weiter, their
ability to change color is based on the physical coordinate
values of the chromatophores stimulated by nerve impulses.
This feature is similar to the algebraic aspects of pixels that
represent numerical values, as Galloway has described.
daher, we might summarize the correspondence be-
tween pixels and chromatophores as follows. Erste, von einem
geometric viewpoint, both are small dots in a larger pattern.
Zweite, just as pixels in a digital image connect to an electri-
cal circuit to emit light in response to an assigned luminance
value, the chromatophores on the body of a cephalopod are
connected to neural circuits, resulting in the contraction of
muscles in response to an electrophysiological signal.
Given that their visual appearance and their functional
system resemble pixels, it might be no coincidence that one of
the etymologies of the word pixel is picture “cell.” Therefore,
if a pixel is a “cell” in a digital image, so too can a chromato-
phore be a “pixel” in a Living Image. Our aim is not just to
appreciate the beauty of chromatophores but also to see the
living cell as a medium for composition of visual artwork.
The significance of this work is discussed below, wo wir
explain the works we created in detail and discuss the pos-
sibilities of expressions created using chromatophores.
ChroMatophony: emBodImenT oF lIvIng ImAgeS
In work similar to ours, Backyard Brains (BB), a company
that sells educational neuroscience laboratory kits, con-
ducted an experiment wherein music was used as the elec-
trical stimulation to manipulate a squid’s chromatophores
[19]. In the video, they stimulate chromatophores by con-
necting electrodes to the fins of a euthanized longfin squid.
The video shows the chromatophores opening and closing,
responding mainly to the low bass and kick sounds of the
song “Insane in the Brain” by Cypress Hill. Greg Gage, co-
founder of BB, explained that this choice was made because
low sounds tend to generate action potentials in motor neu-
rons [20].
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Yokokawa, Masuda and Jo, Chromatophony 253
Feige. 2. Area of chromatophores at different frequencies, 2020.
(© Juppo Yokokawa)
Feige. 1. Audio signal applied to squid skin through audio cable to stimulate
chromatophores, 2020. (© Juppo Yokokawa)
Im Gegensatz, we created music tailored to the character-
istics of the chromatophores and made them audible to
people through speakers to achieve audiovisual unity when
observed. To determine the signals most likely to stimulate
chromatophores, we selected a sine wave as the electrical
stimulus and investigated the relationship between the re-
sponse of chromatophores and the signal while adjusting its
frequency.
For this project, fresh squid was ordered from Yobuko
port, Saga Prefecture, near our laboratory. The squid was
filleted before the experiment and a clipped sample was
gebraucht. The stimulus was applied to the epidermis of the squid
through iron electrodes, which were attached to an audio
cable. Figur 1 shows the setup used for the experiment. Der
voltage of the stimulus was increased until the chromato-
phores exhibited the desired reaction. The distance between
the electrodes was 15 mm, and the voltage ranged from 0.4 Zu
0.8 V. The action potentials of the squid nerve ranged from 5
mV to 10 mV, which differed significantly from the voltages
used in the experiments. This difference may have been due
to the high resistance of the electrodes and the sample. Der
results indicated that the squid’s chromatophores responded
best to stimuli of approximately 90 Hz and barely responded
to stimuli exceeding 800 Hz (Feige. 2). When similar succes-
sive stimuli were given, the response of the chromatophores
could be erratic. The time required for chromatophores to
open in response to the stimuli differed based on their color
(Feige. 3).
Based on these results, we created music to stimulate the
chromatophore by editing a low-frequency stimulus (around
90 Hz) as sound material on Ableton Live. We thereby cre-
ated the video work Chromatophony. The reaction of the
chromatophores was recorded using a digital microscope
(VHX-5000). The result was a computer graphic–like video
in which the geometric movements were coordinated with
our custom music, although the system used was simple and
the responding material was organic (Feige. 4).
Considering the chromatophore as a unit of Living Im-
Alter, the possibilities we can derive from this work should be
further explored. Although the placement and color (RGB)
of each pixel can be specified in advance, stimulating chro-
matophores using electrodes is less accurate, and we do not
have the ability to move individual chromatophores. Wie-
immer, our aim was not to control their organs but to modu-
late the audible thresholds as an aesthetic condition between
living things. Tatsächlich, the result becomes apparent through
Feige. 3. Series of images of skin samples, 2020. Purple
chromatophores responded to the stimulus earlier than
brown chromatophores. The interval between each image
Ist 1/30 S. Scale bars are 1 mm. (© Juppo Yokokawa)
254 Yokokawa, Masuda and Jo, Chromatophony
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Feige. 4. A segment of the waveform of the music produced and corresponding screen captures of Chromatophony, 2020. The video was recorded in full HD and
32-bit (fl oat) Audio-. The interval between images is 1/10 zweite (three frames). (© Juppo Yokokawa)
the fl uidity and dynamic movement in the images, welche
achieves a display that cannot be replicated by soft ware. In
realization Chromatophony ceases to be a mere video artwork
but becomes a site-specifi c one, considering that we had to
acquire fresh squid for each performance. Although it had
to be recorded digitally and shared on a pixel-based screen,
we consider these specifi c features of Chromatophony an em-
bodiment of Living Images.
dISCuSSIon: ChroMatophony AS lIvIng ImAgeS
We discussed Chromatophony by comparing chromatophores
and pixels from the perspective of media theory and dem-
onstrated the distinctive characteristics of images formed by
chromatophores. Our aim for the future is not to replace the
squid’s chromatophores with pixels but to show more diverse
ways of understanding visual expression. Th erefore, below
we expand the discussion and compare Living Images with
digital images.
Über, we defi ne Living Images as aesthetic images gener-
ated from living cells. Johanna Rotko’s yeast-based photo-
graphic project (Feige. 5) [21], Diana Scherer’s root-sculpture
Projekt (Feige. 6) and experiments of natural computation vi-
sualized in slime mold (Feige. 7) [22] are examples of recent
funktioniert. Alexander Fleming’s microbial painting is an early
example of this kind of work. Not only are his images bio-
Kunst, they were also created in the process of scientifi c experi-
mentation using living organisms. As these works are also
the corporealization of living images, we can formulate their
features specifi cally.
Erste, their textures are not restricted to displays or print-
ing limited by arbitrary signals—RGB or CMYK. Traditional
paintings use natural pigments whose colors could not be
quantifi ed easily, and printed materials have unique tex-
tures resulting from the materials used, including the pig-
ment and pulp. Außerdem, the Autochrome photographic
technique used potato starch as a fi lter to realize vivid color
Entwicklung. Living Images make us aware of the texture
possibilities that natural components combined with digi-
tal technologies can create. Zum Beispiel, Chromatophony
combines complex color texture with computational audio
Feige. 5. Johanna Rotko’s yeast-based photographic project, 2014.
(© Johanna Rotko)
Feige. 6. Diana Scherer, Interwoven #14, photography, textile from woven plant
roots, 50 × 60 cm, Hrsg. 5 + 2 AP, 2018. (© Diana Scherer)
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Yokokawa, Masuda and Jo, Chromatophony 255
did not use “pure” natural products, but to claim that living
things are inherently hybrids of the natural and the artificial.
daher, we apply the term aesthetics to Living Images, als es
concerns works of art as well as implying an attempt to criti-
cally examine the senses themselves, which are embodied in
specific technocultural conditions. Daher, Chromatophony is
not a “re-presentation” of concrete pictures or figures but an
attempt to “present” the dynamic process of a Living Image,
which becomes perceivable through cells.
ConCluSIon
We have discussed the idea of Living Images and the his-
torical background of pixels as a prelude to the discussion
of their characteristics. We then compared chromatophores
and pixels in the context of media studies and proposed
Chromatophony as an example of a Living Image. Endlich,
we discussed the characteristics of this work compared to
other bio-art and the possibilities of using Living Images as
visual expressions.
Jedoch, the scope of Living Images is still debatable. Es
is necessary to discuss whether the smallest unit of Living
Images needs to be a cell and whether the cell needs to be
alive. Inevitably, this leads to discussions regarding the ethi-
cal considerations of life and death.
The possibilities of various forms of Living Images that are
not mere replications of photographs or paintings can also be
discussed. In this respect, it is important to represent images
that are recognizable to humans while focusing on the dy-
namic process through which images emerge across species;
this is what distinguishes Chromatophony from other bio-art.
As images flood networked media today, the number of
shares and clicks seems to measure their value. Im Gegensatz,
Living Images cannot be edited or shared as easily. This may
seem inconvenient at first; Jedoch, in today’s world over-
flowing with images, Chromatophony gives us an opportunity
to reconsider the way in which we interact with images. Von
analyzing the units of Living Images and comparing them
with pixels in digital images, we can observe the material
conditions of their vitality, providing us with a fresh perspec-
tive on the theory and history of images.
Feige. 7. Network formation in Physarum polycephalum [24]. (© Seiki Takagi)
Signale. Daher, Living Images can change how we perceive the
historical role that living things played in art, such as carmine
refined from scale insects.
Darüber hinaus, Living Images present unpredictable features
we cannot control. Although the cells themselves can be ana-
lyzed in chemical and physical terms [23], living materials
can also produce spontaneous and contingent movements.
Those reactions sometimes produce novel results in visual
images exceeding our intentions and expectations, and this
is one of the reasons bioart is receiving increasing attention.
Our point is not to praise the beauty of nature in contrast
to artifacts created from it, for the examples we discussed
acknowledgments
This project was supported in part by JSPS KAKENHI (grant nos.
JP17H04772, JP19H01225, JP20H01203 and JP21H00495).
references and notes
4 Hans Belting, An Anthropology of Images: Picture, Medium, Body
(Princeton Univ. Drücken Sie, 2014) P. 11.
5 Belting [4] P. 21.
6 William Myers, Bio Art: Altered Realities (Thames & Hudson, 2015)
P. 7.
1 Alexander Fleming, “The Growth of Microorganisms on Paper," In
Proceedings of Second International Congress for Microbiology, R. St.
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7 Shannon M. Soucy, Jinling Huang and Johann Peter Gogarten,
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2 Atsushi Tero et al., “Rules for Biologically Inspired Adaptive Network
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8 Alexander Galloway, “Pixel,” in The Object Reader, Fiona Candlin
and Raiford Guins, Hrsg. (Routledge, 2009) S. 499–502.
3 W.J.T. Mitchell, What Do Pictures Want?: The Lives and Loves of
Images (University of Chicago Press, 2005) P. 91.
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256 Yokokawa, Masuda and Jo, Chromatophony
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10 Richard F. Lyon, “A Brief History of ‘Pixel,’” Digital Photography II,
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18 Reiter et al. [15].
19 Backyard Brains, “Insane in the Chromatophores” (23 August 2012):
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20 Mera McGrew, “The Science behind the ‘Insane in the Chromato-
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Squid Video,” Mission Blue (27 August 2012): www.mission-blue
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21 Erich Berger et al., Hrsg., Art as We Don’t Know It (Aalto Univ. Drücken Sie,
2020) S. 106–107.
22 William Myers, Bio Design: Natur + Wissenschaft + Creativity (New York:
Museum of Modern Art, 2012) S. 142–145.
23 Alexandra Daisy Ginsberg et al., Hrsg., Synthetic Aesthetics: Investi-
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24 Tero et al. [2].
Manuscript received 27 Oktober 2020.
JuPPo yoKoKaWa is a research assistant at Tokyo Univer-
sity of the Arts.
NobuHiR o MaSuda is a lecturer at Kyushu University in
the Faculty of Design. He received his PhD in literature from
Kobe University, Japan (2013).
KazuHiR o Jo is an associate professor at Kyushu University
in the Faculty of Design, as well as an advisor at the Yamaguchi
Center for Arts and Media (YCAM). He received his PhD in
design from Kyushu University, Japan (2015).
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Yokokawa, Masuda and Jo, Chromatophony 257
CoLoR PL ATE C: ChroMatophony: A poTenTIAl ApplICATIon
oF lIvIng ImAgeS In The pIxel erA
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Screen capture of Chromatophony, 2019. (© Juppo Yokokawa) (See the article in this issue by Yokokawa, Masuda and Jo.)
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