Transcript No Slide Title

European Society for the Study of
Cognitive Systems
London 2005
THE CHILD AND THE WORLD
Robin Allott
INTRODUCTORY
The Child and the World! There is nothing more wonderful to watch
than a small child, 2 or 3 years old, speaking to its mother, holding
a conversation with its mother. It does seem miraculous, as many
have said, that in such a short period a child can reach so far in its
use of this most precious of human possessions, language. In this
presentation I consider how it is possible, in a remarkably short
time, that a child can acquire all the complexities of its parent
language and amass a large lexicon to refer to things in the world,
objects and actions of all kinds, and so begin to have a grasp on
the world in which it finds itself.
Through language the child, and all of us, in time, build up a picture
of the world; the world is reflected in us in the language we have
acquired. Again, an almost miraculous power which only humans
have.
HOW CHILDREN ACQUIRE LANGUAGE
You are a very young child.: you have to discover the internal
structure of a system that contains tens of thousands of units,
which can assembled in an infinite number of combinations. But
only one of those infinite combinations is correct. This system
is human language. ... How improbable it seems that a mere
child can discover the underlying structure and use it to
communicate. Yet most children do so easily and quickly in the
first few years of life.
There are distinct stages in the child’s progress to language.
Stage I
How does the child find the sounds of speech?
First the child has to be able to pick out from the noise all
round it the special sounds which are required for speech
(quite different from shouts and cries and musical sounds
and animal noises). The child is innately able to do this
(various species of animals can also distinguish speech
sounds from other sounds).
This is because each speech-sound is the product of its
own articulatory gesture, that is, of a specific movement
pattern of the speech organs (tongue, larynx, vocal
cords etc). These motor patterns originated in
evolutionary history from the novel application to
produce speech of the (limited) set of elementary
movements (of the limbs and body) which we share with
other animals.
At birth an infant is sensitized to speechsounds which generate neural motor programs
which resonate with the innate set of
elementary bodily motor programs.
Researchers have been able to show that very young
infants can distinguish between different speech
sounds by using clever experimental techniques, for
example recording changes in the infant’s response
(manifested in changes in head-turning or sucking)
when it listens to a succession of speech sounds.
They have found that the infant (the child who
cannot yet speak) can respond to a much larger
number of speech sounds than are required for the
language spoken by its parents. A Japanese infant
may respond to English speech sounds which are
not used by Japanese adults. An English infant may
respond to Chinese speech sounds which Englishspeaking adults cannot perceive or articulate.
Infants are innately prepared to acquire any
language
This early ability to discriminate speech-sounds
more extensive than those in the phonology of the
parent language is narrowed down as the child is,
over months, exposed to the limited range of
speech-sounds found in the speech of its parents.
Stage II
The next stage is when the child starts actually to
produce speech sounds. This occurs naturally as
the motor organization of the articulatory system
(tongue and vocal cords) advances as part of the
overall development of the muscles and brain
structures required for bodily action generally
(including control of arm positions, body postures
and movements).
Stage III
How does the child find the words ?
The child has to be able to pick out the individual words
of the parent language from the stream of speech to
which it is exposed. To the child the sound pattern of
these words will of course be unknown. There has to
be a process which enables a child to latch on to each
word, to discriminate one word from another.
This is a remarkable performance which many eminent
persons have speculated about but without agreeing how
this can be achieved:
"The child somehow has the concepts available before
experience with language and basically learns labels for
already existing concepts." [Chomsky]
“The word falls, one is tempted to explain, into a mould of my
mind long prepared for it.” [Wittgenstein]
What can be the link between the mould and the word,
between the already existing concept and the word?
Stage IV
How does the child find the objects and actions to which the
words are to be attached?
Vision is innate. Humans can recognize an object within a
fraction of a second. Vision is by far the most important
source for the infant’s growing knowledge of the world. Very
young children are able to recognize more and more visual
objects and show that they can see them them by reaching
for them. At four months of age, they can grasp them.
Stage V
How can the child successfully link the word to the
object or action?
The child knows many objects, actions, sounds, colours etc. in the
external world as well as in terms of its own body. For it to find the
appropriate word for an object, the representation of the particular
object in the brain has to be linked with the representation of the
appropriate word in the brain..
There has been a lot of research into the way in which
visual objects are represented in the brain and more
particularly in the visual cortex, and in terms of the
networks of neurons, brain-cells, associated with objects.
What objects have in common is their physical form, their
distinctive shapes. Neuroimaging studies have shown that
distinct regions in the cortex represent objects by shape.
Not surprisingly, infants concentrate on shapes. As a
result, words for visual objects are the first they acquire.
The link between the particular object and the particular
(appropriate) word comes about from the absolutely central motor
character of the brain’s operation, its organisation to produce and
control action.
The brain’s motor system is the key feature both for the visual
perception of a particular object and for the production of the
specific speech-sounds which are required for the word to be
linked to that object.
Visual perception of objects is a motoric process. The
moulds into which, in the language development of the
infant, the appropriate words of the ambient language
will fall, or be fitted, are formed by the neural
representations of the shapes of the concrete objects
extracted from the infant’s stream of visual experience
by the remarkable motor processes of the eye.
The eye scans an object by a rapid succession of movements
(motor commands for the eye muscles produce movement of the
eye up or down, from side to side and obliquely).
Eye movements are composed of saccades and fixations; a
saccade is a rapid movement of the eye to foveate (the fovea is
the central and most sensitive part of the retina) one salient
feature after another; a fixation is a pause in the movement of
the foveated eye when the finer detail of the object at the point at
which the movement is halted is to be obtained.
The pattern of the actions of the eye is the result of a
complicated neural system, heavily researched but not yet fully
described or explained. The outcome of the scanning process is
an extremely intricate network of movements and halts of the
eye, more easily illustrated than described.
A famous Russian neurophysiologist (Yarbus) used a
photograph of a bust of the ancient Egyptian queen Nefertiti
to illustrate this.. He recorded the pattern of movements of the
eye in scanning the photograph.
The graphic shows the complex pattern which resulted.
It is from the motor record of the scanning of an object that
the shape of the object is derived as a distinct neural
representation, a distinct pattern of nerve-cell connections,
in the the brain’s cortical visual system.
This is how the mould or outline of the concept for a visual
object is formed to which the neural motor pattern required
to produce the sound of the word (of the appropriate word
for the object) is fitted..
Stage VI
How is the appropriate word formed and found to be
appropriate, in the sense of fitting into or being directly
associated with the neural mould constituted by the
representation of the visual object in the cortex?
Consider what the situation for the infant or young child is. The
child has been surrounded from birth, enveloped from birth in the
normal case, in a stream of speech sound; the child has been able
to distinguish and be responsive to speech sound as distinct from
other sound; speech sound has often occurred at the same time as
the child is placed amongst objects to which words are eventually
found to refer.
This process can be taking place anywhere in the
world, in any language area. In each different language
area a child will be exposed to a different set of words
found to be appropriate for the visual objects which
the child has already acquired.
How can all these words in thousands of different
languages, multitudes of different words for the same
sets of visual object, be appropriate?
For the time being the question is to be considered for a
single language, the speech and language by which the
child is surrounded, in which it is submerged, as the child
grows, becomes stronger and more complicated in body
and brain.
The question is how the particular word in the particular
language for a visual object, the word which eventually goes
to fit the ‘mould’ or neural store already developed by the
infant for that object, is in some way specially appropriate for
the object and comes to be recognised as such by the infant.
How a word can be appropriate to its meaning leads back
to the way in which in the history of any language words
emerged for particular objects.. How did a particular word
emerge?
At some stage in the history of a human group a
new word emerged for the particular object.
The new word came into general use and survived
because it seemed the fittest word for the object to
members of the originating group.
In what sense could a word be fit for the object to which it
referred? In what sense could the word be said to match
the object?
Let us consider the perception of any object. For many
objects, on seeing them, we can, without saying a word,
perform a hand and arm movement to indicate the object.
For example, we can indicate a circle by forming or
performing a circle with our arms. For a tree, we can, with
some accuracy, even indicate the kind of tree by using our
hands and arms.
We can indicate other objects by pointing. to them, to our
head, our foot, our ear, our eye and so on. Homely visual
objects, a bowl, a cup, a plate, can be indicated by miming the
particular shape.
Other items can be indicated by the appropriate contour, a
step, an edge, a hill. For many objects we can perform actions
to indicate the objects to other persons in our group.
Objects are represented by patterns of action for which we
have acquired the neural representations needed to perform
the actions.
Once we have in our neural store (motor memory) the
pattern of action representing the object, we can, by a
universally available brain process of “motor equivalence”
transfer this bodily pattern of action to the articulatory
system.
Note: Motor Equivalence simply means that the cortical motor program for an
action executed using one set of joints and muscles can at will be equally well
performed using a quite different set e.g. signing your name with your foot
rather than with your hand
Through ‘motor equivalence’ an externally perceivable
bodily gesture becomes an articulatory gesture,
producing a sequence of speech sounds, a unified word,
equivalent to the action.
We can do this because, as considered at Stage I above,
speech sounds are evolutionarily derived from bodily
action, from innate programs for elementary movements
and postures of the arms
This does not mean or require that at any point in the history
of a human group there must have been a developed gestural
language as a precursor to spoken language.
An appropriate word for an object can be generated simply by
imagining how an object might be physically represented or by
concentrating on the visual perception of the object and
transferring this imagined or visual motor pattern to form an
articulatory gesture and so constitute an appropriate word.
Stage VII
We now have arrived at a set of speech sounds forming
a word which matches the object, a word which is
appropriate for the object to which it refers.
How does an infant acquire the word for a visual object
on hearing it? b
From the motor theory of speech perception (Haskins
Laboratories), the hearing of a word by an adult is perceived
in terms of the motor program required to produce the word.
The word is cross-modally transformed into the articulatory
motor program for producing the word.
Similarly for the infant hearing a word, the word as heard is
cross-modally transformed from an auditory to a motor
pattern.
There are well-known examples of cross-modal
transformation by infants, notably the transformation
which must take place when an infant reproduces in its
own face the facial expression of the experimenter.
See the familiar illustration of a very young child doing
this.
The infant in this series of experiments saw and reacted to the
different patterns of the experimenter’s face. It did this by
using its eyes to scan the differing facial shapes.
From these rapid scans the infant’s brain constructed motor
representations, distinct neural network patterns, which
matched, were appropriate for, the different facial shapes.
These motor patterns were then available to allow the infant to
reproduce the facial patterns of the experimenter.
In much the same way, the motor program in the infant’s brain
generated by hearing a particular word, a particular sequence of
speech-sounds, matches the motor program it has already
acquired as a neural representation for the object from the visuomotor processes involved in perceiving the object.
As we recognise a visual object by reacquainting
ourselves with the motor shape of the object, so the
infant ‘recognizes’ the motor structure of the word for the
particular object in the language it is acquiring. The two
fit together, are associated together neurally.
This is how the infant acquires the word and its meaning.
In Wittgenstein’s terms, the word when heard by the infant falls
into the mould constituted by the neural representation of the
object.
In Chomsky’s terms, the infant acquires the appropriate label for
the concept of the object, a label which is not random or arbitrary
but designed to match the motor shape of the object to which it
refers.
Sections not included in the presentation see:
www.percepp.com/langacqu.htm
Action word acquisition by children
Acquisition of words by children for things or processes
perceived by other senses than vision or action organisation
Acquisition of closed class words
Acquisition of sentence-structure
Community acquisition of sentence structure
Acquiring the ability to construct the meaningful sentence
NOTES
Sections not included in the presentation see: www.percepp.com/langacqu.htm
1. MOTOR THEORY
2. ARTICULATORY GESTURE
3. MOTOR EQUIVALENCE
4. KANT'S CATEGORIES AND FUNCTION WORDS
5. WORD AND CONCEPT CORTICAL TOPOLOGY
6. VISION AND THOUGHT
BIBLIOGRAPHY AND REFERENCES