Ambiguity
in Art and in the Brain
Public
lecture by Semir Zeki
Centre for the History of Science,
Technology and Medicine,
Manchester University, UK
October
30th 2003
Reviewed by Robert Pepperell
pepperell@ntlword.com
"Commercial Ambiguity
"Use Dr. _____ Sachets de Toilette,
and mothers and daughters will look
like sisters." Gentlewoman
–(cited in Punch,
October 1907)
With new art historical work being
published on ambiguous 'potential
images' [1], and the hybrid discipline
of neuroaesthetics becoming more widely
recognised as a specific strand in
the larger debates about art and consciousness
[2], I was intrigued to learn what
one of the leading proponents of neuroaesthetics,
Semir Zeki, had to say about the neurological
basis of ambiguity. The exploitation
of ambiguity has been a deliberate
artistic strategy not only amongst
modern and contemporary practitioners
but throughout the pre-modern world
and across many different cultures.
Sometimes ambiguities have been presented
as a kind of amusement or curiosity
(as in certain optical devices, or
the quote above) and sometimes as
a ways of profoundly affecting the
viewer, resisting stasis and multiplying
perceptual and conceptual possibilities
(as in analytic cubist paintings or
Vermeer's enigmatic domestic interiors).
Zeki's contribution is to attempt
an account of artistic ambiguity from
a neurological standpoint, drawing
on his own extensive research into
colour constancy and the nature of
visual perception. He is keen from
the outset to situate his analysis
within the context of consciousness
studies, and in particular to stress
his theory of 'microconsciousness'.
In contrast to those who regard conscious
experience as singular and unified,
Zeki proposes a model in which the
various functionally specialised areas
of the brain (such as those responsible
for colour perception or motion perception)
in themselves constitute regions of
conscious activity needing no higher
interpretation. The impression we
have of an immediate holistic conscious
experience is in fact illusory given
that, as Zeki has shown experimentally,
we see colour a fraction of a second
before we see motion, even though
a moving red bus seems to form a perceptual
unity. Over longer time frames (greater
than one millisecond), such temporally
distributed events form a 'macroconscious'
state, which might be further modulated
by those higher conscious states conditioned
by culture and language, ultimately
generating the kind of conscious awareness
we associate with our everyday general
activity. Even though these higher
conscious processes are prone to error,
by misconstruing the reality of what
is present in the world, the functionally
specialised areas cannot in themselves
be fooled into seeing what is not
there. The perception of colour, for
example, can never be ambiguous because
colour is nothing but a product of
functionally specialized brain regions.
As Newton had already pointed out,
there is no colour 'out there' in
the world for us to see, only variations
in the frequency of electromagnetic
radiation which we experience in a
chromatic register.
Although many perceptual processes
result in visual experiences that
we cannot consciously influence (such
as colour), there are other kinds
of visual phenomena that are subject
to cognitive contingencies –
ambiguous images being prime examples.
In the familiar Necker cube or Schroeder
staircase (examples from Zeki's lecture
can be found at http://turner.stanford.edu/art/zeki_images/)
we are able to some extent to determine
the apparent orientation of the object,
which lies in one of two directions.
(I would also suggest it is possible
to see other kinds of orientations,
but for the purposes of this review
I will accept the convention that
there are two). In such cases, Zeki
argues, the functionally specialised
visual areas (those responsible for
recognising lines and angles) draw
upon other brain processes, notably
those concerned with memory and experience,
to produce a cognitive interpretation
containing spatial information that
is actually absent in the image. It
is this cognitive interpretation which
is prone to vacillate between the
ambiguous readings, but which is also
subject to some degree of conscious
control insofar as we can force ourselves
to see one orientation or the other.
For Zeki, this way of understanding
ambiguity differs markedly from its
dictionary definition as 'doubtful'
or 'uncertain'. On the contrary, each
of the possible interpretations is,
for the viewer, an utter certainty,
albeit a certainty that can change
from one moment to the next. The microconscious
brain region associated with any particular
perceptual state gains a kind of sovereignty
over the moment of experience; if
only for a given time it dominates
or occupies the cognitive high ground.
This then is what Zeki terms the "neurological
definition of ambiguity", the
evolutionary rationale for which,
he claims, is the inherent survival
advantage in flexibility of interpretation.
Applying these principles directly
to the analysis of art, one finds
cases from across art history (and
Zeki concentrates almost exclusively
on the traditional European canon)
in which artists leave open, or leave
unresolved certain parts of the work
in order that the viewer (or indeed,
listener) can more freely interpret,
which although demanding greater cognitive
resources rewards with greater semantic
richness. The 'unfinished' marble
carvings of Michelangelo and the Belvedere
Torso are exemplary cases.
Despite the fact that the thesis is
not particularly ground-shifting,
certainly to many aestheticians
or psychologists of art, it does have
to advantage of being supported by
some robust physical data. It also
raises some fascinating philosophical
questions about the nature of reality
as constituted by the brain. I raised
some of these questions in a later
discussion with Professor Zeki, and
in particular I asked him about the
assertion he made during the course
of the lecture to the effect that
"ambiguity is a property of the
brain and not of the external world".
This, I felt, not only presupposes
an essential rupture between brain
and world, but also might suggest
a relegation of the role of the art
object itself in the production of
the ambiguous effect. He replied by
stressing the evolutionary imperatives
which must have formed our perceptual
apparatus, especially the fact that
the brain is so selective in what
it chooses to recognize as it searches
for what he calls 'constancies', i.e.
patterns, regularities and invariant
forms. In doing so it discards, or
simply fails to register mountains
of other data which is not essential
to the conduct of the organism. Part
of this inherent efficiency lies in
our very capacity for interpretation,
which allows us to evaluate possible
states of the world that may not easily
be determined – at least before
it's too late. So, for example, a
wary smile from a potential adversary
might be a benign invitation or a
concealed threat. So it seems that
the brain reflects the potential ambiguity
of the world, but moreover allows
us to negotiate it with the benefit
of our acquired experience.
One further statement made in the
lecture caught my attention, the claim
that the "brain can accommodate
contradictions". He was referring
specifically to Johann Winkelmann's
description of classical sculpture
as carrying an essentially contradictory
meaning, at once violent, aggressive,
turbulent and at the same time sublime,
composed and static. This contradictory
ambiguity, as Zeki claims, can be
held by us as an aesthetic whole,
and is manifest in works like the
Belvedere Torso. Bu this raised in
my mind the equally intriguing possibility
that, in contradiction of Aristotle's
principle of non-contradiction, Zeki's
neurological evidence might offer
grounds for the naturalization of
a dialethic approach, one in which
contradictory states are accommodated
simultaneously without the necessity
for resolving them one way or the
other. He responded by distinguishing
between two modes of neurological
time, the very short (less that one
millisecond) in which possibilities
are 'collapsed' into one orientation
or another, and longer time frames
(over one millisecond) in which various
and contradictory orientations might
be accommodated as the possibilities
'flip-flop' from one to another.
There is little doubt that Zeki's
work in this field could contribute
to our scientific understanding of
the nature of art and, indeed, of
perception and consciousness. He is
clear that art, science and philosophy
are epistemologically convergent,
but seems to have difficulty persuading
his colleagues in the scientific community
of the value of taking artist's investigations
into perceptual behaviour seriously.
Equally, from the artistic standpoint
one is entitled to be critical of
approaches that seek to reduce complex
sensory and cultural phenomena to
neurological processes, albeit such
processes are inordinately complex
in themselves. But there is certainly
an intrinsic value in sharing ideas
and stretching methodological boundaries,
even if that means both science and
art have to examine their own working
assumptions. One perceptive audience
member in the lecture asked in response
to Zeki's claim that art and science
were indistinguishable, "Does
that mean science is ambiguous?"
It was heartening that his reply was
a cautious affirmation
[1] Gamboni, D. (2002) Potential
Images: Ambiguity and Indeterminacy
in Modern Art.
London: Reaktion Books (reviewed online
in Leonardo Reviews, July 2003).
[2] Zeki, S. (1999) Inner Vision:
An Exploration of Art and the Brain.
Oxford: OUP. (reviewed online in Leonardo
Reviews, May 2003).
