The Act of Creation (74 page)

Chapter
XII
), even the artificial stamping-in of a trace in this type of
experiment is not purely mechanical, and not comparable to the action
of the recording needle on the gramophone disc.

 

 

In the intermediary ranges of the scale we find blends of varying
proportions between 'bit learning' and 'whole' or pattern-learning; and
lastly, at the opposite end, the input is analysed in all its relevant
aspects by the various 'competent' perceptual hierarchies, until it is
saturated, as it were, with meaning. This, I shall suggest, is what we
mean by 'insight-learning'. Insight thus becomes a matter of degrees --
and not, as the Gestalt school seemed to hold, an all-or-nothing process.

 

 

The key-word in the previous paragraph was 'competent'. The amount of
'stamping in' needed, and the type of learning which will occur, depends
on the animal's (native and acquired) perceptual organization -- in
other words, on its 'ripeness' for that particular kind of task. If this
sounds like a truism, one still wonders how conditioning -- 'classical'
or 'operant' -- could ever have been regarded as the paradigm of all
learning.

 

 

 

Abstract and Picture-strip

 

 

Memory of a sort is found on every organic level, from protozoa upwards.
The human nervous system we assume to be equipped with a hierarchy
of memory-systems operating on various levels: from short-lived,
unstable modifications in the receptor organs, to stable and enduring
central 'engrams' and the codes of complex skills. Since perception and
memory-formation proceed in a continuous series, and since perception
filters the input, we are led to the apparently paradoxical conclusion
that the most enduring memory-traces must be those which have been most
thoroughly de-particularized -- it is to say, impoverished. This seems
indeed to be the case at least in so far as one important category of
hierarchies is concerned: the abstractive category.

 

 

When one is watching a play at the theatre the successive sounds emitted
by the actors must be retained by short-term memory until they can
be bracketed together into words or larger syntactic sub-wholes. The
psychological present embraces various-sized chunks of the immediate
past (by means of a 'nmemic afterglow', of reverberating circuits,
or what-have-you). By the time the actor utters his next line, the
perceptual relata -- the speech-units -- of the previous line have
already been forgotten, and only the wording is still retained. A few
lines further the exact wording of the first phrase is also wiped off the
memory slate, and only its content is still stored on some higher level of
the hierarchy. The next day one still has a fairly detailed recollection
of the actual sequence of scenes in the play; a few months later only
an outline of the plot as a whole remains in the 'store'. Parsimony
in memory-formation demands that only a mere skeleton of the complex
original experience should be retained on the highest level of a given
hierarchy; and vice versa, that the trace which an input leaves shall
be the more enduring, the higher the level to which it has attained by
successive stages of de-particularization and re-coding.

 

 

The example I described was of an abstractive hierarchy governed
exclusively by logical analysis. A computer built on these lines, after
being fed a number of West End plays, would probably filter down all
that it found worth retaining, to a formula such as: isosceles marriage
triangle with pet-dog at centre of gravity, or: whodunit with five
independent variables (suspects).

 

 

Let us assume that at each stage of this serial abstractive process,
the input activates some particular scanning- or filtering-device which
is 'attuned' to that particular input. The receiving end of that device
corresponds to its 'matrix' aspect: it is potentially responsive to a
great many inputs which have one specific feature or pattern in common,
and are thus equipotential in that respect. When an input is 'recognized'
by the matrix as conforming to that pattern, it will emit a code-signal
to the higher echelons. But while the matrix is 'attuned' to a great
number of variations in the input pattern, the code merely signals
the invariant aspect of it, e.g. 'a triangle', 'an octave', 'a fly',
'a denial'. The size and position of the triangle, the particulars of
the fly, the wording of the denial are lost in the coding, and cannot
be retrieved by reversing the process within that particular hierarchy
(though it may have been preserved by another).

 

 

Thus the analysing-devices behave' like analogue-to-digital computers,
and in other respects, too, the order of events is the exact reverse
-- as one would expect -- of the processes we have observed in
motor-hierarchies. When an animal engages in some skilled action, the
coordinating centre activates a matrix of equi-final motor patterns;
which particular sub-skill will be called into activity depends on
circumstances. Thus the 'roughed-in' action-programme becomes more and
more particularized in the course of its descent to the periphery -- while
contrariwise, the peripheral input is more and more de-particularized or
'skeletonized' in its ascent towards the centre. The first is a process
of progressively spelling out implicit orders; the second an equally
stepwise process of abstracting the meaning implied in the mosaic of
sensations. Both processes are irreversible: the exact words of the
actors in the play cannot be retrieved.

 

 

It can also happen, however, that one has quite forgotten what that
play, seen years ago, was about -- except for one particular detail,
an inflection of voice, an imploring gesture of the heroine which,
torn from its context, remains engraved on one's memory. There exists,
indeed, a method of retention which seems to be the direct opposite of
memory-formation in abstractive hierarchies. It is characterized by the
preservation of vivid details, which, from a purely logical point of view,
are often quite irrelevant; and yet these quasi-cinematographic details
or 'close-ups', which seem to contradict the demands of parsimony, are
both enduring, strikingly sharp, and add texture and flavour to memory.

 

 

Bartlett, in a classic experiment, made his subjects read an Indian
legend and then reproduce it on repeated occasions at intervals of
increasing length -- ranging from fifteen minutes after the first reading
to several months or years. The story was about thirty lines long; it
concerned a young Indian who got involved in the 'War of the Ghosts',
and was wounded in the process. The last paragraph read:

 

He told it all, and then became quiet. When the sun rose he fell
down. Something black came out of his mouth. His face became
contorted. The people jumped up and cried. He was dead. [10a]

 

Twenty subjects were tested. Their written recollection of the story
shrank with the passage of time to a few lines which, in most cases,
distorted its content almost 'beyond recognition'. But, with one
exception, all the spaced-out versions of all subjects, even after several
years, contained the lines: 'Something black came out (or "issued" or
"rushed" or "jumped out") of his mouth.' The one exception wrote (after
four months): 'My remembrance was in visual terms . . . of breath somehow
materializing into a ghost.'

 

 

Fiction and autobiography abound with examples of such
'vivid-fragment-memories': the mole on Granny's chin, the fly crawling
over the lump of sugar at the moment of the dramatic climax. Let us call
this the 'picture strip' type of memory -- although, of course, the 'vivid
fragment' may be auditory or olfactory, or even a whole 'cinematographic
sequence' -- like the detailed, auditory-visual sequences which Penfield
evoked in his patients through electric stimulation of their exposed
temporal lobes (see below).

 

 

Obviously the formation of such 'picture-strip traces' must also be
preceded by some filtering process; but in this case the criteria of
relevance and parsimony are different, and often directly opposed to those
of the abstractive hierarchies. The vivid detail is usually described
as 'striking', 'attractive', 'evocative', 'nostalgic', 'frightening';
it always has some
emotional
significance. It is mostly on a
pre-verbal level; but even verbal fragments -- of a poem, of a chill
warning or whispered endearment -- are retained because of their affective
quality. The filter-matrices that operate in these hierarchies must be
emotionally 'attuned' -- let us say to some hypothalamic controls. We
may further assume that such picture-strip memories are formed on lower
(pre-conceptual) levels than memories of the abstractive kind; they may
be symbolic, but their symbolism too is often pre-verbal, and perhaps
related to the symbolism of the dream; they may even obey their own
special brand of parsimony. We have seen that occasional regression to
lower levels of the hierarchy is a conditio sine qua non of creativeness;
the combination of the abstractive and picture-strip type of memory may
serve the same purpose --
vide
Coleridge and Kekulé.

 

 

We are thus led to assume the existence of various hierarchies in
perception and cognition, whose criteria of relevance are determined by
the attitudes, drives, emotions, which they serve; they interlace with
each other on every level, and thereby provide the multi-dimensionality
-- or multi-colouration -- of experience; at the same time they also
compensate for the impoverishment of experience in the process of memory
formation. The outstanding memory which some geniuses are said to have
possessed may possibly be due to their many-dimensional ways of analysing
and storing experiences.

 

 

 

Learning to See

 

Let us turn to vision.

 

 

Innate perceptual organization provides no more than the primitive
foundation on which learning can build. The long controversy between
Behaviourists and the nativistically inclined Gestalt school whether
perceptual organization is innate
or
learned has finally been
superseded by the more realistic question
how much
is innate and
how much acquired by early learning. The consensus seems to be that colour
and brightness constancy, and the recognition of line, angle, and texture
are innate in rats as well as men. [11] So is 'primitive unity' (Hebb) --
the segregation of simple figures as coherent entities from the background
(for instance, a black splash on a white card). But when it comes to more
complex figures where the contrast is less marked, even the figure-ground
relation is strongly influenced by learning and expectancy. I have
quoted examples from the neglected field of auditory perception where the
relativity of figural unity is obvious. The radiologist whom experience
has taught to see a peptic ulcer or a lesion of the lung, treats the
much sharper contours of the ribs as 'background'. When you hunt for
a collar-stud in a drawerful of miscellaneous objects, that small,
insipid form, poor in Gestalt
Prägnanz
, will 'stick out a mile';
the remaining contents of the drawer are 'background'.

 

 

Thus even figural coherence is influenced by past experience and present
attitude. When it comes to the
identification
and recognition of
visual Gestalten, it has been shown that even the simplest of them --
triangles, squares -- require an element of learning. The behaviour of
chimpanzees reared without pattern vision, of human beings with congenital
cataract who had to 'learn to see' after they were operated on, and the
cumulative evidence from other experiments indicate, in Hebb's words,
'that the normal human infant goes through the same process, and that we
are able to see a square as such in a single glance only as the result of
complex learning'. [12] The learning process seems to depend mainly on
visual exploration: a two-year-old child will recognize a triangle that
has been rotated by 120 degrees only after rotating its own head; [13]
but even in the adult, perception is bound up with exploratory motions
of the eyes, from conscious movements to the involuntary, minute motions
('drift', 'flick', 'tremor') which move the image across the fovea when
the eye seems 'fixed' on a stationary object. Identification of a triangle
or square seems to depend on serial scanning of its contours. [14]
With practice, the scanning motions may become summary or subliminal;
but when scanning is artificially eliminated by a mechanical device,
the image disintegrates into fragments. '
Wir tasten mit unserem Blick
das Sehfeld ab
', Exner wrote in 1891 [15] (We finger over the visual
field with our gaze).

 

 

Thus with the exception of brightness and colour constancy, and a few
other primitive 'innate skills', visual perception is inextricably bound
up with learning, i.e. with memory. What we perceive in audition is not
the linear pulse of pressure-variations arriving at the eardrum, but an
'inferential construct' of individual voices, instruments, musical or
verbal phrases; and what we perceive in vision is not the camera-image
on the retina but the 'inferential construct' of people and objects
which preserve their constant shape and size, regardless of angle
and distance. The eye may be a camera, but immediately behind its lens
there is a series of compensating, correcting, and retouching devices --
the perceptual matrices of skilled vision.

 

 

 

Knowing and Seeing

 

 

The best-known among these are the matrices responsible for the
visual constancies and illusions which are found in every elementary
textbook. Less attention has been paid to the modification of
automatically functioning perceptual matrices by verbal leaning and
verbal suggestions, by attitude and expectation. [16] Mitscherlich,
an outstanding observer, had denied that there existed any structural
difference between the two types of tartaric acid of opposite optical
activity. Pasteur, using the same apparatus, saw at once the asymmetric
facets on the tartar crystals because his hypothesis on molecular
structure demanded that they should be there. [17]