The Ghost in the Machine (13 page)
of behaviour; in the second case,
it can display very marked
self-assertive
tendencies -- the
proverbial 'stubbornness of habits'. Whatever clever 'strategies' you
use to disguise your handwriting, you cannot fool the expert and get
away with it in court. The same goes for your gait, accent of speech,
the use of favourite turns of phrase. Habits are behavioural holons,
governed by rules which mostly operate unconsciously. Taken together,
they constitute what we call personality or style. But each holon also
has a margin of strategic choices, and that margin of choice increases
in ascending order with the increasing complexity of higher levels. And
if we ask what determines the conscious choices at the apex, we again
find ourselves in a regressing series.
Filters
So far we have been concerned with 'output': the spelling out of intent
into action, including the 'intent' of the fertilised egg to grow into
an adult, and of a fertile idea to grow into articulate language. Before
we turn to the 'input' side -- sensations and perceptions -- it might
be useful to revert for a moment to the analogy of a military operation
in old-fashioned, classical warfare.
The General in Command issues an order which contains the plan of action
in broad outlines; this is transmitted from Divisional Headquarters
to Brigade Headquarters to Battalion Headquarters, and so on; at each
successive echelon in the hierarchy the plan is more elaborated until the
last detail is filled in. The reverse process takes place in collecting
information about the movements of the enemy and the lie of the land. The
data are collected on the lowest, local levels by patrols reconnoitring
the terrain. They are then stripped of irrelevant detail, condensed,
filtered and combined with data from other sources at each higher echelon,
as the stream of information flows upward along converging branches of
the hierarchy. Here we have a very simplified model of the working of
the sensory-motor nervous system.
On the motor side, we had a series of 'triggers'. On the perceptual side
we have instead a series of 'filters' or 'scanners', through which the
vital input traffic must pass on its ascent from sense-organ to cerebral
cortex. Their function is to analyse, de-code, classify and abstract
the information that the stream carries, until the chaotic multitude
of sensations, which constantly bombard the senses, is transformed into
meaningful messages.
Of most of these input-processing activities we are blissfully unaware.
They are performed by a whole hierarchy of processing agencies built into
the apparatus of perception. On the lowest level, there is the screening,
or filtering out, of sensations that are irrelevant to the activity in
hand or the mood of the moment. One is normally not aware of the pressure
of the chair against one's backside, nor of the contact between skin
and clothing. The eye and the ear are also equipped with such selective
screening contrivances ('lateral inhibition', 'habituation', etc.).
The next stage in processing is very striking -- once one starts thinking
about it. If you hold the index finger of the right hand ten inches,
the same finger of the left hand twenty inches, in front of your eyes,
you
see
them as being of equal size, although the image on the
retina of one is
twice as large
as the other. People moving
about in a room do not seem to shrink or grow in size -- as they should
-- because we
know
that their size remains constant, and this
knowledge somehow interferes with the visual input at some level of the
nervous system, and falsities it in the noble cause of making it conform
to reality. The photographic lens has no such built-in mechanism; it
will honestly show the left index finger twice as large as the right,
and a sunbathing girl's foot stretched out towards the camera as a case
of elephantiasis. 'Even our elementary perceptions', wrote Bartlett,
'are inferential constructs' [2]; but the inferential process functions
on unconscious levels of the hierarchy.
The tendency to see a familiar object as of its actual size, regardless of
distance, is called by psychologists the 'size constancy phenomenon'. Not
only the size but also the colour and shape of the retinal image of a
moving object is all the time changing with its distance, illumination and
angle of vision; yet we are mostly unaware of these changes. Accordingly,
to the phenomenon of size constancy we have to add those of colour and
shape constancy.
The constancies are only a part of our repertory ofperceptual skills,
which form the grammar of vision, and provide the 'rules of the game'
that enable us to make sense out of the ever-changing mosaic of our
sensations. Though they operate automatically and unconsciously, they
can be modified by learning. When a subject in a psychological laboratory
puts on inverting glasses which turn the world, including his own body,
upside down, he is at first completely lost, unable to walk, and may
also feel seasick. After a few days of constantly wearing the glasses
he readjusts himself to living in a visually upside down world. The
adjustment requires at first great conscious effort, but in the end the
subject seems hardly aware that the world is upside down. The retinal
image remains inverted, and so of course is its projection in the brain,
but his mental image -- there is no other word for it -- is now the right
way up; and when at this stage the glasses are taken off, it takes him
some time to readjust to normality.*
* This is a simplified account of a somewhat controversial subject.Our perceptual habits are as stubborn as our motor habits. It is as
For details, see, for instance, Gregory [3] and Kottenhoff. [4]
difficult to alter our way of seeing the world as it is to alter our
signature or accent of speech; each habit is governed by its own canon
of rules. The mechanisms which determine our vision and hearing are
part of our perceptual equipment, but operate as quasi-independent
functional holons, hierarchically ordered along the entwined trees of
the nervous system.
The next step upward in the hierarchy leads to the baffling phenomena of
pattern-recognition -- or, to put it differently, to the question how
we abstract and recognise universals. When you listen to a gramophone
record of an opera with, say, fifty instruments in the orchestra and
four voices singing, and then look at the record with a magnifying
glass, the whole magic is reduced to the single wavy, spiral curve of
the groove. This poses a problem similar to that of how we interpret
language (cf.
Chapter II
). The airwaves, too, which
carry the opera into the ear, have only a single variable: variations of
pressure in time. The individual instruments and voices have all been
superimposed on each other: violin, flute, soprano, and what have you,
have been scrambled together into an acoustic porridge, and the mixture
threaded out into a kind of long noodle -- a single modulation pulse which
makes the eardrum vibrate faster and slower with varying intensity. These
vibrations are broken down in the inner ear into a sequence of pure tones,
and that sequence is all that is transmitted to the brain. Any information
regarding the individual instruments whose production has gone into the
porridge seems to be irretrievably lost. Yet as we listen, we do not
hear a succession of pure tones; we hear an ensemble of instruments and
voices, each with its characteristic timbre. How this dismantling and
reassembling operation is performed we understand only very imperfectly
to date,* and no textbook of psychology seems to deem the matter worthy
of discussion. But we know at least that the timbre of an instrument is
determined by the series of partials which accompany the fundamental,
and by the energy-distribution among them; together they provide the
characteristic tonal spectrum of the instrument in question. We identify
the sound of a violin or flute by reconstructing this spectrum -- that is,
by picking out and bracketing together its partials, which were drowned
among thousands of other partials in the composite air-pulse. In other
words, we abstract a stable pattern from the acoustic flux -- we fish out
of it the timbre of the flute -- and of course the timbres of a number of
other instruments. These are the listener's stable auditory holons. They
in turn combine, on the higher levels of the hierarchy, into patterns of
melody, harmony, counterpoint, according to more complex rules of the
game. (Melody, for instance, is a pattern quite different from timbre,
extracted from the same medley of sounds by tracing different variables:
rhythm and pitch.)
* See The Act of Creation, pp. 516 ff.Melody, timbre, counterpoint, are patterns in time -- as phonemes, words
and phrases are patterns in time. None of them makes sense -- musical,
linguistic, semantic sense if considered as a linear chain of elementary
units. The message of the air-pressure pulses can only be de-coded by
identifying the wheels within wheels, the simpler patterns integrated
into more complex patterns like arabesques in an oriental carpet. The
process, as already mentioned, is made to appear more mysterious by
the fact that time has only a single dimension. But a single variable
is sufficient to encode all music ever written -- provided there is a
human nervous system to de-code it. Without it the vibrations caused by
the gramophone needle are just so much moving air.
However, the recognition of patterns in space presents a no less difficult
problem. How does one recognise a face, a landscape, a printed word, at
a glance? Even the identification of a single letter, written by various
hands, in various sizes, and appearing in various positions on the retina,
and hence on the optical cortex, presents an almost intractable problem
for the physiologist. In order to identify the input, the brain must
activate some memory-trace; but we cannot have memory-traces which match
all and every conceivable variation of writing the letter /f/ -- not to
mention several thousand ideograms, if one happened to be Chinese. Some
very complex scanning process must be involved which first identifies
characteristic simpler features in the complex whole (visual holons --
like loops, triangles, etc.); then abstracts the relations between these
features; and then the relations between the relations. Our eyes are
in fact constantly engaged in a variety of different types of scanning
motions, of which we are unaware; and experiments show that when scanning
activities are prevented, the visual field disintegrates. Scanning the
visual field means translating what is simultaneously given in space
into a succession of impulses in time -- as the TV camera transcribes
its visual field into a succession of impulses in time, which are then
re-translated by the receiving set into the image on the screen. And
vice versa, when we listen to speech or music, the nervous system
extracts patterns in time by bracketing together the present with the
reverberations of the immediate past, and with memories of the distant
past, into one complex process occurring in the specious present in
the three-dimensional brain. It constantly transposes temporal into
spatial patterns, and spatial events into temporal sequences. In Lashley's
classic dictum: 'spatial and temporal order appear to be almost completely
interchangeable in cerebral action'. [5]
Thus at the series of relay stations through which the input-stream must
pass, it is subjected to filtering, scanning and analysing processes,
which strip it of irrelevancies, extract stable configurations from
the flux of sensations, analyse and identify patterns of events in
space and time. A decisive stage is the transition from the perceptual
to the cognitive levels of the hierarcy -- from sight and sound to
meaning. The sounds of the syllables /fiu/ and /lañ/ mean nothing.
They are nonsense-syllables, unrelated to each other. But a relation
instantly emerges when we learn that /fiu/ means 'boy' in Hungarian,
and /lañ/ means 'girl'. Once we have invested the sound of a
syllable with meaning, it cannot be divested of it.
The meaning we attach to these sound-patterns is agreed by the conventions
of language. But man has an irrepressible tendency to read meaning into
the buzzing confusion of sights and sounds impinging on his senses; and
where no agreed meaning can be found, he will provide it out of his own
imagination. He sees a camel in the cloud, a face hidden in the foliage
of a tree, a butterfly or an anatomical detail in the ink-blot of the
Rohrschach test; he hears messages conveyed by the booming of the church
bells or the rattling of carriage wheels. The sensorium extracts meaning
from the chaotic environment as the digestive system extracts energy
from Food. If we look at a Byzantine mosaic floor, we do not perceive it
as an assembly of individual stone-fragments; we automatically combine
the fragments into sub-assemblies -- ears, noses, draperies; and these
sub-assemblies into individual figures; and these into a composite
whole. And when the artist draws a human face, he follows the reverse
procedure: he first roughs in the outline of the whole, then sketches
in eyes, mouth, ears, as quasi-independent sub-structures, perceptual
holons which can be schematised according to certain tricks and formulae.
The hierarchic principle is inherent in our modes of perception; but it
can be refined by learning and practice. When an art student acquires an
elementary knowledge of anatomy, it improves not the skill of his fingers,
but the skill of his eye. Constable made a study of the various types
of cloud formation and classified them into categories; he developed a
visual 'cloud vocabulary' which enabled him to see and paint skies as
nobody had done before. The trained eye of the bacteriologist or of the
X-ray specialist enables him to identify the objects he is looking for,
where the layman only sees shadowy blurs.
If Nature abhors the void, the mind abhors what is meaningless. Show
a person an ink-blot, and he will start at once to organise it into a
hierarchy of shapes, tentacles, wheels, masks, a dance of figures. When
the Babylonians began to chart the stars, they first of all grouped
them together into constellations of lions, virgins, archers, and
scorpions -- shaped them into sub-assemblies, celestial holons. The first
calendar-makers wove the linear thread of time into the hierarchic pattern
of solar days, lunar months, stellar years, Olympic cycles. Similarly,
the Greek astronomers broke up homogenous space into the hierarchy of
the eight heavenly spheres, each equipped with its clockwork of epicycles.
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