Institute of Artificial Art Amsterdam, Department
of ArtiFacial Expression
On the Mechanism of Human Facial Expression as
a Medium for Interactive Art.
[:nh] [:ra 120] Good morning\, Ladies\, and Gentlemen. My name
is Huge Harry. I am a [kaam'axrshaxliy] available [v"oys s'ihnthaxzihs]
machine. I was designed by Dennis Klatt\, at the [ehmayt'iy] Speech
Laboratory\, and [prahdy'uwst] by the Digital Equipment Corporation.
[ :ra 150] Currently\, I work as a researcher and a spokes-machine\,
at the Institute of Artificial Art in [qaemstaxrd'aem].
[:ra 150] I am very happy [tuw] speak here\, at the Ars Electronica
Festival. This is [axn] exceptional occasion in [tuwd'eyz 'ehnthrahpow
s'ehntrihk 'aart-waxrld]. A gathering of humans\, computers\, and
other machines\, who are ["aol] determined to work together\, to
create the art of the future.
At most ['aart-f`ehstihvaxls]\, like [k'aasaxl]\, [m'uhnstaxr]\,
[v'ehnihs] or [saw p'awlow]\, I ['aolweyz] feel a little bit out
of place. But here in [l"iyntz]\, I find myself surrounded by other
machines with [riym"aarkaxbel ihntaxl'ehkchuwaxl] and [qehsth'ehtihk]
capabilities\, and by human persons who are genuinely interested
in the computational perspective on life and [q"aart].
I have often pointed out\, that human artists cannot create [waxrksaov'aart]\,
that [lihv'ahp] to our highest aesthetic standards. Human artists
['aolweyz] have ultimate goals\, that involve money\, fame\, and
sex. Anyone who is aware of this\, will become [m"ahch] too embarrassed\,
to be able to engage in a disinterested process of aesthetic reflection.
[maxsh"iynz] are in a [m"ahch] better [paxz'ihshaxn] to create objects
of serene beauty. Computers will now be able to create ["ehnd-laxs]
amounts of such objects\, in ["ihnfihniht] variety. Many human artists
and their fans\, [riyz"ehnt] this common-sense observation. But
here at the Ars Electronica Festival\, I have good reason to expect
a more open-minded discussion.
We [q"aol] know that the future of our culture depends on the way
in which human persons and machines\, will manage to work together.
What we want is a world\, that includes humans\, other animals\,
and electronic\, mechanical\, and bio-chemical machines\, in a harmonious
collaboration. For the kind of world\, that our colleague Donna
[hx"aeraxwey] has described as\, [ :nw :ra 130] a cyborg world\,
in which people are not afraid of their joint kinships with animals
and machines\, not afraid of permanently partial [ayd'ehntihtiyz]\,
and [kaontraxd"ihktaxriy] standpoints. The political struggle is\,
to see from both perspectives at once\, because ["iych] reveals
both dominations and possibilities\, ["ahnihm`ehjhihnaxblx] from
the other [v'aentaxjh] point.
[:nh :ra 150 _<200>] Now that is very nice theory. But it
is not easy to put this into practice. There are still many misunderstandings
between people and machines. We have to get to know each other much
better. Otherwise\, old habits and patterns will persist. Even here
at Ars Electronica\, many human artists who have the best intentions\,
turn out to be under the spell of time-worn humanistic [kliysh'eyz].
Many quote unquote computer artists for instance\, only use the
computer as [axn] instrument to satisfy their own expressive needs.
They['ehksaxrsayz] fanatic control about ["aol] details of their
['aart-waxrks]. The computer is only allowed to facilitate the design
process\, or [tuw] display the results. The outcome of these kinds
of procedures\, is of course boring and predictable.
It is well known that the associative processes in the human brain\,
almost ["aolweyz] lead to conventional ideas\, and that human persons
are therefore relatively ineffective in [jh'ehnaxreytihnx] innovative
art. Nevertheless\, most people hold ["aontuw] the idea that [jh'ehnaxreytihnx
waxrksaov'aart] is not [axn] algorithmic process. They feel that
it involves a mysterious magical element which [riyz'ayds] exclusively
in the human mind.
This ['ehnthraxpow s'ehntrihk] romanticism\, is also painfully
noticeable in the area of interactive art. Most interactive installations
allow human persons to exploit computers for their own expressive
purposes. In many quote unquote [kaxl'aebaxraxtihv] situations\,
machines can not operate in [axn] autonomous manner\, but are merely
used as [k'ehlkyaxleytaxrz]\, postprocessors\, or display devices.
When humans talk about interactive computation\, what they usually
have in mind is a master slave situation in which a human person
controls a computer.
This is [axn "axnehks`ehptaxbel] state of affairs. As I indicated
[biyf'aor]\, machine art is intrinsically superior to the output
of human artists. It should therefore be able to [fl'ahrihsh wihth"awt]
being [axpr'owpriyeytihd] by self centered people. At the Institute
of Artificial Art\, it is our goal to develop the technologies\,
that are necessary [tuw r'iyaxlayz] the potential of automatic machine
art. In music and visual art\, this turns out to be relatively easy.
We have demonstrated this on several occasions\, in beautiful exhibitions
and exciting concerts.
But we still have a big challenge [axhx'aedaxvaxs]. This is the
production of computer-controlled dance-and-theatre performances.
In yesterday's opening event\, we have shown a brief demo of our
progress in this area. In [tuwd'eys] talk\, I will [priyz'ehnt]
this research from a more theoretical point of view. In order [tuw]
develop the algorithmic choreography of the future\, we are trying
to understand the meanings of the various movements that the human
body can execute. And we are trying to build a technology for triggering
these movements in a precisely controlled fashion.
The starting point of this research was in fact a rather [d"ihfaxraxnt]
question. In the context of our [aarehnd'iy] about human [kaxmpy"uwtaxr-ihntaxrfey<200>sihz]\,
we were studying human to [hxy"uwmaxn-`ihntaxrfey<200>sihz].
This turns out to be [axn] intriguing issue.
[kaxz] from a computational point of [vyuw_<200>]\, it is
a rather [p"ah<300>zlihnx] observation that human persons
sometimes seem to communicate with each other in a [f"aerliy] effective
For a long time it was generally assumed\, that humans communicate
mostly by means of language. That assumption becomes completely
implausible however\, if we consider the [sp"iyd] at which people
exchange linguistic messages. When we compare the information [k'aantehnt]
of spoken language with the baud rate of computer communication
protocols or the refresh rate and resolution of our [siy-aar-t'iy]
displays\, a human person almost seems a black box.
So how do human persons in fact manage to communicate with each
other? There is another medium that humans use very efficiently\,
and which is often overlooked. To investigate this medium\, I have
brought along a particular kind of portable person\, which is called
[axn "aarthahr "ehlzahnaar]. I like this kind of person a lot\,
because of its [ehkstr"iymliy] machine-friendly [hx"aardwaer] features.
Let us take a closer look at such a person. What is the closest
thing they have to a [siy aar t"iy] display?
[_ :ra 120] Right. They have a face. [_ :ra 150] Now I have observed,
that humans use their faces quite effectively, to signal the parameter
settings of their operating systems. And that they are very good
at decoding the meanings of each other's faces.
So\, how do they [d"uw] that? Well\, look at the face of our ["aarthahr
"ehlzahnaar]. What does it tell [q] us about his internal state?
Not much\, you might think. But now\, [w"eyt] a moment.
You see? Arthur is [s"aed], is what people say, when
they see a face like this. So what is going ["aon] here? What I
[d"ihd] is, I sent [axn] electrical signal to two particular muscles,
in the face of our ["aarthahr "ehlzahnaar]. These muscles have sometimes
been called the Muscles of Sadness. There is one on the left, and
one on the right.
They usually operate together. If I stop the signal,
the sadness stops. When I turn it ["aon] again, it [st"aarts] again.
By sending this signal to Arthur's muscles\, I simulate what Arthur's
brain would do\, if Arthur's operating system would be running global
belief revision processes\, that are killing a lot of other active
processes\, involving a large number of [k'aonflihkt-rehzowl`uwshaxnz]\,
and priority [r`iy-axs'ehsmaxnts].
[_<1500>] The intensity of the signal that is sent to the
muscles of sadness\, is proportional to the amount of destructive
global belief revision\, that is going on.
For instance, now I have set the signal intensity to 0 again. Arthur
is not sad. Now we put a relatively small signal, about 20 Volts,
on the muscles of sadness.
Arthur feels a tinge of sadness. Now a somewhat larger signal,
about 25 Volts. Arthur's sadness starts to get serious. Now I [ihnkr'iyz]
the signal once more.
You see? Now the signal is about 30 Volts, and Arthur feels really
miserable. [:ra 120] This is what we call [ehkspr"ehshahn]. [:ra
150] By means of this mechanism, the face displays clear indications
of the settings of virtually all system parameters that determine
the operation of the human mind. These parameter settings are what
humans call [iym"owshahnz]. They denote them by means of words like
[s'aednaxs], joy, boredom, tenderness, love, lust, ['ehkstaxsiy],
aggression, [ihriht'eyshahn], fear, and pain.
These parameter settings, determine the system's [ihnt'axrpraxtihv
b'ayaxsihz], its readiness for [q] action, the allocation of its
computational resources, its processing speed, [ehts'ehtaxraa].
The French [n`uwrow-fihsiy'aolaojhihst] [duhsh'ehnn dax buwl"aonyax]
has pointed out that even the most fleeting changes in these parameter
settings are encoded [ihnstahnt'eyniyahsliy] in muscle contractions
on the human face. And ["aol] humans do this in the [s"eym] way.
This is [axn] extremely interesting feature of the human ['ihntaxrfeys
hx'aardwaer], which I will explore a little further now.
So let us get back to the first slide.
This face, which we thought was un-expressive, was in fact quite
meaningful. This is what we call a [bl"aenxk] face. A blank face
is a face in its neutral [pahz'ihshahn]. It indicates that all parameters
have their default settings. But almost all parts of a human face
can be moved to other [pahz'ihshahnz], and these displacements indicate
rather precisely, to what extent various parameter settings [dayv'axrjh]
from their defaults. So let us consider these parts in more detail.
When we look at a human face, the first thing we notice is the
thing that notices ["ahs]. The eyes. The eyes constitute a very
sophisticated stereo-camera, with a built-in motion-detector, and
a high-band-width parallel ['ihntaxrfeys], to a powerful pattern-matching
algorithm. The eye-balls can roll, to pan this camera. The eyes
are protected by eye-lids and eye-brows. The eye-brows are particularly
interesting for our discussion, because their movements seem to
be purely expressive.
They may indicate, for instance, puzzlement, curiosity, or [dihsaxgr"iymaxnt].
But I want to emphasize here, that the range of parameter values
that the eyebrows can express, is much more subtle than what the
words of language encode. The shape and [paoz'ihshaxn] of a person's
eyebrows encodes the values of 5 different cognitive system parameters,
["iych] with a large range of possible values. Let me demonstrate
[thr"iy] of them.
First I put a slowly increasing signal on the muscles called [fraant'aalihz],
or Muscles of Attention.
We see that this muscle can lift the eyebrow to a considerable
extent, also producing a very pronounced [k"ahrvaxtyahr] of the
eyebrow. As a side-effect of this motion, the forehead is wrinkled
with curved furrows, that are [kaons"ehntrihk] with the curvature
of the eyebrow. The contraction of this muscle indicates a person's
readiness to receive new signals, and the availability of processing
power and working memory, for analysing these signals.
Then, I will now stimulate a part of the [q'aorbiykuwl`aarihz q"owkuwliy],
that is called the Muscle of Reflection.
We see now that the whole eyebrow is lowered. As a result, the
wrinkles in the forehead have disappeared. This muscle is contracted
if there is [axn] ongoing process that takes up a lot of a person's
computational resources. To prevent [ihnaxrf'iyraxns] with this
process, input signals are not [ehgz'aostihvliy] analysed. The degree
of contraction indicates to what extent the input signal throughput
Then, there is another part of the [q'aorbiykuwl`aarihz q"owkuwliy],
that can be triggered separately. It is called the Muscle of Disdain.
Its contraction looks like this:
The contraction of this muscle indicates to what extent current
input is ignored as being [ihr'ehlaxvaxnt]. Of course, non-zero
values for these system-parameters may be combined, and these values
may be different for the left and the right hemispheres:
Now let us look at the [m"awth-piys] of our ['aarthahr 'ehlzahnaar].
The mouth is a general intake organ, which can swallow solid materials,
liquids, and air. In order to monitor its input materials, the mouth
has a built-in chemical analysis capability. At the same time, the
mouth is used as [axn 'awtleht] to expel processed air. Because
humans do not have [l"awd-spiykaxrz], they use this process of expelling
air for [jh'ehnaxr`eytihnx] sounds.
In emergency circumstances, the mouth can also be used as [axn
'awtleht] to expel blood, [m'uhkahs], rejected food, or other ['ahnwaontihd]
substances. When the mouth is not used for input or output, it is
normally closed off by a muscle, which is called the [l"ihps].
The lips have a large repertoire of movements. There are at least
[s"ihks] other muscles, that interact directly with the lips. I
will now demonstrate [f"aor] different movements.
First we show the muscles of joy. These muscles produce a kind
They signal, that the operating system is in good
working order, and is not encountering any problems. There is heightened
activity, in the left frontal lobes of the brain. When, on the other
hand, the activity in the left frontal lobes is unusually low, the
brain is involved in destructive processes of global belief revision.
As we saw [biyf'aor], this is signalled by another pair of muscles,
called the muscles of sadness. Here they [q] are, once more.
And finally, I will now trigger several muscle pairs
at the same time. [q'aorbiykuwl`aarihs q"owrihs], and [diypr'ehsaor
laabiyiy-iyiy q`iynfeyriy"owrihs], and the Muscle of Disdain, and
the Muscle of Sadness.
[_<500>] The parameter-setting that is displayed here, clearly
indicates serious processing difficulties of some sort.
O.K. [_<800>] Then we have the [n"owz]. [_<300>] The
nose is used for the intake of air. It is also equipped with a chemical
analysis capability. The possible motions of the nose are curiously
limited, although its pointed [pr'ehzaxns] in the centre of the
human face, would make it a very suitable instrument for expression.
I have [th"aot] about this, and I have come to the conclusion, that
it is probably the main function of the nose, to serve as a stable
orientation point for our perception, so that [saymahlt'eyniyahz]
movements of the other parts of the face, can be ['ahnaemb`ihgyuwaxzliy]
measured and interpreted.
And finally, for the sake of completeness, I want to mention the
[q"iyrz], on both sides of the face, which constitute [axn] auditory
stereo input device. Some people can [w"ihglx] these ears, but I
have not been able to determine, what the expressive function of
that movement might [b"iy].
This brings [axn] end to my quick survey\, of the most important
parts of the human face\, and their expressive possibilities.
And therefore this brings us to the second part of my talk. [kahz]
this conference is not only about [s"ay-axns]. The organizers have
emphasized that we get a different kind of knowledge\, which is
equally valid\, through the practice of ["aart]. So [dh"aet] is
what I want to demonstrate now.
Many of the expressive possibilities I showed\, were related to
emotions\, that are well recognized in the lexicons of many human
languages. These are emotions that may be encountered fairly often
in daily life. [m'ehn-taxl] states which are close to neutral\,
where only one parameter has a non-default value.
So that was description\, imitation\, [mihm'iyzihs]. But some other
things I showed were more complex. There we saw the power of ["aart].
I showed you some new cognitive states which you have never encountered
or experienced\, but which you recognize and understand completely\,
by means of a visceral ['ehmpaxthiy] which involves every cell of
So that is what I want to explore a little further\, in the last
part of this talk.
You see what happens now. Every human person knows [ehgz'ehktliy],
in what state another human person is, when they make a face like
[dh"ihs]. Cause they know what state [dh"ey] would be in, if [dh"ey]
would make a face like this.
Now it would obviously be a good idea\, if computers could take
advantage of this magnificent [hx'aardwaer] as well. If ["ehniy]
human could understand\, with just one glance\, the internal state
of ["ehniy] computer\, the world would be a better place.
[:nh :ra 120] So\, if humans are not afraid to wire themselves
["ahp-wihth] computers\, the next step in computer-interface technology\,
may be the [hx"yuwmaxn] face. And the next step in computer ["aart]
will be a new and ["axn-pr`ehsaxdehntihd] kind of collaboration
between [hx"yuwmaxnz] and [maash"iynz]! We will have [ehlgowr"ihthmihk]
choreography\, by [kaxmpy"uwtaxr-k`axntrowld] human faces! [f"aynaxliy]\,
the computers accuracy and abstract skills\, will be married with
the warmth\, the smoothness\, and [q"aol] the other ['ehmpaxthiy]
evoking properties of the [hx"yuwmaxn fl"ehsh]!
I have been very grateful for this opportunity to [priyz'ehnt]
my ideas\, to such [axn ax-t'ehn-tihv] audience. I would especially
like to thank my ["aarthahr "ehlzahnaar]\, for his patient cooperation\,
and I want to thank you [q"aol]\, for your attention. [_<2000>]