William James developed an account of 'ideomotor action' on
lines similar to those earlier proposed by Lotze. Lotze had
suggested that the mental image of a definite movement had
attached to it as a necessary result the appearance of that
definite movement. James termed 'ideomotor response' the
experience that when the subject vividly imagines moving his body
he has a marked tendency to do what he is thinking. "Every
representation of a movement awakens in some degree the actual
movement which is its object. We think the act and it is done.
An
anticipatory image of the sensorial consequences of a movement
is
the only psychic state which introspection lets us discern as the
forerunner of our voluntary acts. Movement is the natural
immediate effect of feeling". James went on to suggest how one
may experience this for oneself: "Try to feel as if you were
crooking your little finger, whilst keeping it straight. In a
minute it will fairly tingle with the imaginary change of
position; yet it will not sensibly move, because it's not really
moving is also a part of what you have in mind. Drop this idea,
think of the movement purely and simply, with all brakes off, and
presto! it takes place with no effort at all." William James'
introspective account has more recently been complemented by
approaches in terms of cerebral motor control by, for example,
Pribram and Jeannerod.
Introspective observation is what we have to rely on first and
foremost and always. Introspection is difficult and fallible.. the difficulty is simply that of all observation of whatever kind.
There is now
research evidence (using PET and MRI scanning) which demonstrates
that bodily action is preceded by a mental picturing of the
proposed action (something Pribram called an Image of
Achievement). That is, a perceptually-organised pattern is
transduced into a motor program and executed by the changes in
posture, changes in limb positions which constitute human action.
This gives a neurological realisation of what in evolutionary
terms must have been an intimate intertwining of perception and
action not as separate functions but as part of single system for
effective behaviour in any creature's environment. What this
paper goes on to consider is whether if action follows on from
brain image, does the converse apply? does externally perceived
action produce an internalised motor program which is available
in its turn to be imaged and then expressed by action of the
perceiving individual? If so, this throws light on something of
very great importance but which has remained poorly understood
until now, the nature of imitation. It also has many other
applications or implications, for example, the impact of TV,
video or film scenes of action, the behaviour of crowds or mobs,
or more generally conformist behaviour, the operation of language
in hypnosis or oratory. There are of course detailed questions
open to research: the nature of the transition between visual
image and motor program, the relation between language and
action, the location in the brain of the processes linking vision
and motor programs, the scope for simulating such processes in
artificial intelligence, the implications for evolutionary
psychology, the contact with thought about representation.
1. Action is preceded by image, that is, visualisation
of the action provides the structure for the action executed
2. Perception of external action provides structure for
creation of the internal motor program for action
3. The circuit is completed:
Visual perception of external action
= Imitation
Mead:The relation of imitation to the theory of animal
perception [1907]
Thorpe: how is it that man achieved this extraordinarily
perfect imitative ability?
Hayek: A great capacity for imitating, that is, translating
perceived into performed movements. This may indeed have been
one of the most important steps in the development of the
brain.
Yando, Seitz and Zigler [1978 Imitation: A developmental
perspective] Piaget has described such clear changes in
imitation as a function of changes in a child's level of
cognitive development. Piaget has suggested that newborn
infants are not capable of true imitation at all. The nature
of imitation remains in many ways a mystery.
Maratos: Imitation touches upon many different aspects of
functioning of the human mind, i.e. intersensory perception
and intermodal coordination, emotional and motivational
issues, cognitive capacities, developmental theories, etc. The
phenomenon still seems to puzzle the neuroscientists and the
developmental psychologists.
In motor imitation actors match their own movements to
those of a visually presented model. Although humans are very
accurate in imitating many complex motor skills, as can be
observed for instance in sport, the mechanisms that underlie
successful imitation in the domain of sensory- motor
coordination are poorly understood. [Max Planck Institute for
Psychological Research
Molnar and Nagy: the so called Meltzoff-Moore effect (the
astonishing imitative capacity of newborns)
Meltzoff and Moore carried out well-conceived,
well-controlled and statistically-validated experiments to
investigate imitation by newborn infants of adult facial
gestures.
Infants between 12 and 21 days of age can imitate both
facial and manual gestures... Such imitation implies that
human neonates can equate their own unseen behaviors with
gestures they see others perform. (Meltzoff and Moore 1977:75)
The hypothesis we favor is that this imitation is based on
the neonate's capacity to represent visually and
proprioceptively perceived information in a form common to
both modalities. The infant could thus compare the sensory
information from his own unseen motor behavior to a
`supramodal' representation of the visually perceived gesture
and construct the match required. ... Our recent observations
of facial imitation in six newborns- one only 60 minutes old -
suggest to us that the ability to use intermodal equivalences
is an innate ability of humans.(Meltzoff and Moore 1977: 78)
Newborn infants ranging in age from 0.7 to 71 hours old
were tested for their ability to imitate 2 adult facial
gestures: mouth opening and tongue protrusion. ... The results
showed that newborn infants can imitate both adult displays.
(Meltzoff and Moore 1983: 702)
infants use the equivalence between the act seen and the
act done as the fundamental basis for generating the
behavioral match. ... this imitation is mediated by a
representational system that allows infants to unite within
one common framework their own body transformations and those
of others. According to this view, both visual and motor
transformations of the body can be represented in a common
form and thus directly compared. (Meltzoff and Moore 1983:
708)
How does a child (or, for that matter, an adult) transfer a
pattern of light or sound into a pattern of muscular control
that serves to reproduce a structure functionally equivalent
to the model? The hypothesis to be entertained is that
imitation is a specialised mode of action in which the
structure of an amodal percept directly specifies the
structure of the action to be performed. (Studdert-Kennedy
1986: 206)
The structural foundations for the imitative movements
cannot be learned. It is necessary to assume an innate
structure that at least partly matches the structure of the
adult models to explain both imitation and more complex
reciprocal or complementary interactions which are
characteristic of communication between child and adult from
immediately after birth.(Trevarthen 1984: 253, 256)
If you see someone yawning, you will probably yawn. If you think about (visualise or form a mental image of yourself)
yawning, you will probably yawn. All bodily movements are
changes in posture - and posture is body-image. We visualise
any movement (of arm, leg, head, hand, mouth) as a change in
body-image, a change in posture - the movement brings our
actual posture into coincidence with our visualised new
body-image, visualised posture. This is readily linked to the
newborn infant's ability to mimic adult facial movements. The
hour-old baby protrudes its tongue when it sees the adult do
so.
Imitation of actions or sounds seems to require ability: 1.
to perceive external patterning (looking or listening); 2. to
analyse the perceived external patterning into discrete
uniform elements; 3. to transfer the set of elements to
another functional system in the brain, possibly transform
them there and form them into a production program; 4. to
activate the production program through the peripheral devices
of the second functional system (produce imitated speech,
imitated facial expression, imitated bodily action).
Deecke, Luder. 1996. Planning, preparation, execution and
imagery of volitional action. Cog. Brain Res. 3: 59-64.
Decety, Jean. 1996. Do imagined and executed actions share
the same neural substrate? Cog. Brain Res. 3: 87-93
Berthoz, Alain. 1996. The role of inhibition in the
hierarchical gating of executed and imagined movements. Cog.
Brain Res. 3: 101-113
Jeannerod, M. 1994. "The representational brain: Neural
correlates of motor interaction and imagery". Behavioral and
Brain Sciences 17: 187-245. [June 1994]
Kosslyn: The research we have completed over the past ten
years has just been summarized in a book [Image and Brain The
Resolution of the Imagery Debate MIT Press]. We study the
neural substrate underlying visual mental imagery; for
example, we have used PET to show that many of the same
structures that are involved in object recognition are also
involved in imagery.
Trends in Neurosciences February 1997 Motor imagery: never
in your wildest dream. Crammond, Donald J. page 54-57
[Hayes and Demiris. 1994] Robot learning by imitation. The
field of learning by imitation is largely untouched. Robots as
ethological tools with which to study learning by imitation.
[Bakker and Kuniyoshi ETL Tsukuba Science City Japan 1996]
Robot See, Robot Do. A spate of recent papers on robot
imitation by researchers in Japan, Europe and Australia. The
first few tentative steps towards robot imitation have already
been taken. Recent work at ETL is drawing on insights from
developmental psychology to address some of these problems in
a practical way.Imitation is not an innate behaviour; it must
be learned [according to Piaget and Yando]. Children are at
first unable to imitate at all, and can only imitate novel
behaviours (with limited success) after the age of 12 months.
[Minsky] The future work of mind design will not be much
like what we do today. Some programmers will continue to use
traditional languages and processes. Others programmers will
turn toward new kinds of knowledge-based expert systems. But
eventually all of this will be incorporated into systems that
exploit two new kinds of resources. On one side, we will use
huge pre-programmed reservoirs of commonsense knowledge. On
the other side, we will have powerful, modular learning
machines equipped with no knowledge at all. To program today,
we must describe things very carefully, because nowhere is
there any margin for error. But once we have modules that know
how to learn, we won't have to specify nearly so much---and
we'll program on a grander scale, relying on learning to fill
in the details.
[Greco] the only thing everyone agrees on is the fact that
'representation' is not a completely clear and unambiguous
term. the concept of representation has become more and more
linked with the adjective 'symbolic' ... However, this
connection is now questioned by many. "what is the
relationship between symbolic (or high-level) representations
and sensory or neural processes? "The main shortcoming of
symbolic theories is that symbols cannot refer only to other
symbols, but sooner or later they must refer to something else
(this is the so-called symbol-grounding problem). This
something else, in Sommerhoff's view, must be primarily some
response pattern (e.g. some neural or motor activity) that
directs behaviour.
[Sommerhoff] "mental images .. have much in common with
real visual perceptions. ... they seem to engage broadly the
same cortical areas as direct vision.
[Patel] "The nature of representation - if this term still
has any relevance -
[Greco] " A list of examples of representations (or sets of
representations) could be endless: I shall mention only some
of them: linguistic symbols, mathematical symbols, visual
patterns, even visual fields or images. representation as an
internal event (a process, or a product of a process) ...
working as a causal connection between stimuli and responses.
... where does the causal power of representations come from?
... from their interpretation. In other words: because they
are symbolic.
Representations (visual) of:
Persisting external objects
For visual objects, the "grounding", the initial piece of
grit around which later visual and other experience accretes,
is the (closed) pattern of saccades and fixations, the
characteristic set of eye movements, on first scanning the
object. The structure to which each pattern is referred is the
set of hard-wired high-level elementary motor programs from
which all actions, all bodily movement, must be constructed.
No doubt something equivalent takes place for other sensory
modalities.
INTROSPECTING [William James]
Ideomotor action: Wherever movement follows unhesitatingly and immediately the
notion of it in the mind, we have ideomotor action. We are then
aware of nothing between the conception and the execution... We
think the act, and it is done; and that is all that introspection
tells us of the matter... it is no curiosity, but simply the
normal process stripped of disguise... the determining condition
of the unhesitating and resistless sequence of the act seems to
be the absence of any conflicting notion in the mind.
We know what it is to get out of bed on a freezing morning in
a room without a fire ... probably most persons have lain on
certain mornings for an hour at a time unable to brace themselves
to the resolve... Now how do we ever get up under such
circumstances? ... we more often than not get up without any
struggle or decision at all. We suddenly find we have got up. A
fortunate lapse of consciousness occurs ...the idea flashes
across us, "Hollo! I must lie here no longer" - an idea which at
that lucky instant awakens no contradictory or paralyzing
suggestions, and consequently produces immediately its
appropriate motor effects.
I The imitation circuit
II Innateness of imitation
II Motor imagery, motor perception, motor execution
IV Artificial intelligence and imitation
V Imitation and representation
I The imitation circuit
Creation of internal motor program for action
Translation of internal program into external action
II Innateness of imitation - Notes
Motor imagery, motor perception, motor execution
p. 62 "motor imagery set (mental representation of motor
acts). The 'visualization' of a motor act, i.e. to internally
envisage a motor act without that it actually takes place is
the topic of the present special issue [based on Vienna
symposium 1994 'Mental representation of Motor Acts'] ... it
seems likely that imagery activates the same areas of the
brain that are activated by actual perception.
p. 87 "Motor imagery can be defined as a dynamic state
during which a subject mentally simulates a given action ...
The same reasoning that is used in visual imagery research can
be extended to motor imagery, by assuming that motor images
share the same neural mechanisms as those that are responsible
for preparation and programming of actual movements
p. 92 "These results altogether suggest that mental
representations during observation of action performed by
others ... share common neural mechanisms with other covert
aspects of motor performance, such as planning and
programming.
p. 101 "PET data showing that indeed the same structures
are activated in both types of movement [imaginative and
executive] support this idea.
p. 107 PET scan showing this in Neuroreport 5 (1994) 921-
924 Lang, Petit et al.
p. 187 "motor imagery ... the general idea of this target
article is that actions are driven by an internally
represented goal rather than directly by the external world.
... relying on identifiable building blocks ... Motor
representations are not objects of contemplation; they are
normally rapidly transformed into movements.
Motor imagery would ... relate to the representation of the
self in action ... the teacher and pupil situation during the
action of learning a motor skill like playing a music
instrument. The pupil watches the teacher demonstrating an
action, with the instruction of later imitating and
reproducing that action. Although the pupil remains immobile
during the teacher's demonstration, he must image in his mind
the teacher's action.
p. 190 "Recently, these authenticated that the same
neurons also fire while the monkey observes the experimenter
[or another monkey] performing the same action [as the monkey
itself had previously performed] [Di Pellegrino et al. 1992
"Understanding Motor Events" Experimental Brain Research 1992
91: 176-180.
p. 54 "Research into motor imagery, the mental rehearsal
of a motor act, is providing new insights into the
representation of willed action. ... Results from a wide range
of studies supports the notion that motor imagery and
execution involves activities of very similar cerebral motor
structures 'at all stages of motor control'[ ] ... These
results ... suggest that imaged movements are constrained by
the same physical laws and physiological limitations that
apply to our everyday motor behaviors ...
Artificial intelligence and imitation: Notes
[Minsky] Why can we build robots that compete with highly
trained workers to assemble intricate machinery in
factories---but not robots that can help with ordinary
housework? It is because the objects and activities of
everyday life are too endlessly varied to be described by
precise, logical definitions and deductions.
Representation: Notes from Cog. Systems. 4-2 August
1995
[the non-symbolic approach] "the main function of
representation is the one I shall call correspondence.
According to this idea, the effect of stimulation starts with
transduction and hence gives rise to a modification of neural
states ... a variation of internal states corresponding to a
variation of external (or bodily) states
"What happens to these corresponding or isomorphic events?
Subsequently they should detach themselves from the simple
correspondence function, they must stop working as simple
mirrors and start to substitute.
[Hampton] What do we mean by "representation". Different
forms
of knowledge will have different forms of representation.
Practical knowledge (Knowing How) like using a computer
keyboard, or driving a car is represented as "motor programs"
in the brain - the programs can become so automatic that the
mind just reacts in the appropriate fashion to the changing
environment without much conscious thought.
Aspects of objects (properties, views)
Configurations of objects (situations)
Sequences of configurations (events and actions)