Language is a skilled activity. In the development and acquisition of the skill, imitation may play different roles. Imitation in language may be related to and throw light on the role and functioning of imitation in other areas including imitation in robotics.

A new emphasis on the bodily basis of language in relation to imitated speech and gesture, and more specifically on cerebral motor organisation as providing a possible new approach to the symbol- grounding problem.

A linguistics perspective, though much expanded beyond current mainline linguistics.

The relation between imitation and language: accounts from different disciplines

Linguists and others

Most linguists do not believe that learning a first language is anything like the kind of controlled and directed learning that is involved in acquiring skills or a second language in an adult

Psychologists on imitation and language

The intermodal or amodal relationship of perception and action provides the basis for imitation. This also seems to be the case for the relation between speech production and speech perception, and for the relation between gesture and speech.

Neuroscientists and others on imitation and language

Mirror neurons research is of increasing significance for many areas of human functioning.

Robotics, imitation and language

A roboticist conflation: keep the model behaviourally relevant, constrained with data from neuroscience, psychophysics and ethology, particularly integrating findings from research into mirror neurons

Where now?

1. much uncertainty and disagreement about the nature of imitation

2. no consensus about how humans acquired the capacity to represent things by words

3. innate imitation rather than training or instruction

4. very considerable problems remaining in robotics but some indications of a move under way from computational to biologically inspired robotics.

Motor Control, Language, and Imitation

Imitation involves a close and complex relation between the neural basis for movement and the neural basis for perception. The same is true for language

An outline of the way in which the brain organises and controls the execution of all types of bodily action, including articulatory action, is gradually becoming apparent

Mirror Neurons [recent research]

Listening to speech specifically modulates the excitability of neurons for the tongue muscles

The phoneme recognition mechanism could be involved in phonetically ‘understanding’ others’ speech because the speaker and the listener share the same articulatory motor repertoire.

The existence of audiovisual neurons suggests how the meaning of actions could be linked to hearing spoken language.

2002 The Cortical Control of Movement Revisited. Michael S.A.Graziano, Charlotte S.R. Taylor, Tirin Moore, and Dylan F. Cooke, Department of Psychology, Princeton. Neuron, 36, 349-362, October 24, 2002.

Stimulation of each cortical site in the right hemisphere evoked a different final posture of the left hand and arm. The dotted lines show the frame-by-frame position of the hand during stimulation.

Regardless of the starting position, stimulation caused the hand to move toward a specific final position.

"One possibility is that the mechanisms for speech were built on a preexisting mechanism for motor control" (Graziano et al.355)

MOTOR THEORY OF LANGUAGE

Mirror neurons, motor primitives and motor imagery research fit closely with the motor theory of language origin and function.

The motor theory is that there is a direct relation between the functioning of speech and motor control generally, with language depending on pre-existing motor primitives coupled with the operation of motor equivalence.

The motor control of the tongue is a section of the total system of motor control for all bodily movement. Tongue movements can be explained in terms of a small number of independent muscle groups, each corresponding to an elementary or ‘primitive’ movement

Motor equivalence is demonstrated most remarkably in the relation between speech and gesture. Motor equivalence can operate from speech to gesture or from gesture to speech and from vision to speech

Motor Primitives

Individual speech sounds are motor primitives

Words formed from primitive speech-sound elements are motor programs

Movements of the arm are the motor equivalents of the speech primitives

Before we produce a sentence there is a motor image of the sentence

A sentence is a high-level motor program or action plan.

The Motor Theory in operation: an example

CONCLUSION

Language and imitation are closely related by the intermediation of motor control.

Behaviour-based robotics is well-placed to take advantage of neuroscience research focusing on these two major aspects of human functioning.

Support material:
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THE PHYSICAL FOUNDATION OF LANGUAGE: Exploration of a Hypothesis 1973
THE NATURAL ORIGIN OF LANGUAGE: The Structural Inter-relation of Language, Visual Perception and Action 1981
THE MOTOR THEORY OF LANGUAGE ORIGIN 1989
THE GREAT MOSAIC EYE: Language and Evolution 2001