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FW: Gestural Origins of Language by Place/Catania

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  • Popplestone, Ann
    Ann Popplestone CCC TLC 216-987-3584 ... From: Paulo Oemig [SMTP:oemigp@CVWRF.STATE.UT.US] Sent: Thursday, February
    Message 1 of 1 , Feb 26, 2000
      Ann Popplestone
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      From: Paulo Oemig [SMTP:oemigp@...]
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      Subject: Gestural Origins of Language by Place/Catania

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      30. It is proposed that in previous linguistic training the behaviour of
      picking (nota bene) the drawing of a car (the target in the case of the
      upper figure), when presented with the written word CAR as sample, and the
      behaviour of picking the written word CAR (the target in the case of the
      lower figure), when presented with the drawing of a car as sample, have both
      been reinforced. As a consequence these two stimuli are treated as
      equivalent and are said to have become members of the same stimulus
      equivalence class. Although in this particular example the equivalence class
      has been formed by linguistic training outside the laboratory, there is a
      wealth of experimental evidence showing that in human children and adults
      any two arbitrarily selected stimuli can be formed into an equivalence class
      by this procedure. Despite the fact that the experimental technology tends
      to restrict research to the investigation of arbitrary associative links
      between static visual shapes (but see Sidman [1990] Figure 4.2, p.95, for an
      experiment in which the sample is spoken word), it is generally agreed by
      workers in this field that the ability to form stimulus equivalence classes
      in this sense is intimately associated with the early stages of language
      development in the human infant.
      31. According to the view endorsed here (Place 1995/6), an arbitrary
      response-produced stimulus becomes a symbol for or name of some individual
      object or kind of object, property, relation or event when, as illustrated
      in the schematic, it becomes a member of a stimulus equivalence class which
      includes amongst its members one or more natural signs of the presence of
      the individual or kind which it thereby symbolises. The propensity of the
      child that is developing language to form such stimulus equivalence classes
      is seen as a result of having repeatedly learned both, as speaker, to
      produce the symbol or name in the presence of a natural sign of the thing it
      'stands for' and, as listener, to pick out the natural sign when presented
      with the symbol or name.
      32. Despite many attempts to do so, there is no convincing evidence that
      any animal species, including apes who have been taught to use sign-language
      or other symbols, has spontaneously developed a stimulus equivalence class
      in the way human children invariably do, i.e., unless the individual has
      been specifically trained to respond to each of the possible combinations of
      sample and comparison. There is evidence, moreover (Beasty 1987; Dugdale &
      Lowe 1990; Horne & Lowe 1996), which links the emergence of spontaneous
      stimulus equivalence class formation with the use of names to distinguish
      the stimuli the child is learning to associate. Animals who have been taught
      to use symbols not only fail to show the spontaneous formation of stimulus
      equivalence classes. They also fail to show the exponential increase in
      vocabulary size which has been referred to as the naming explosion and which
      would seem to begin in the child at about the same time (around the age of
      two). It seems that a mutation has been selected which gives human beings
      the ability to form the kind of associations involved in giving significance
      to arbitrary symbols far more readily than any other species.


      33. Because the work that has been done on the formation of
      stimulus equivalence classes has focused on static visual stimuli, it is
      directly relevant only to the acquisition of object-names. How action-names
      are acquired has not been studied from this perspective. However, it seems
      likely that this ability grew out of the ancient practice of representing
      actions by mimed movement, just as the ability to acquire object-names
      appears to have grown out of the practice of pointing at objects in order to
      establish reference to them. Once object-names and action-names have been
      acquired it becomes possible to construct sentences in what Bickerton (1990)
      has called proto-language in which sentences consist of an object-name or
      noun specifying the agent, an action-name or verb specifying the action to
      be performed, and a second object-name or noun specifying the manipulandum.
      Horne and Lowe's (1996) 'Daddy push car' is a typical example of just such a
      sentence. Apart from the distinction between verb and noun and the order in
      which the different components of the argument structure occur, such
      sentences are devoid of syntax. Nevertheless, within their limitations, they
      provide the rudiments of a working symbolic language.

      34. As language develops in the child and as it presumably developed in
      the species, reference is initially restricted to objects in the current
      common stimulus environment of sign-producer and sign-receiver to which the
      sign producer refers by pointing at them. With the introduction of iconic
      representation reference is extended to objects which are absent from the
      common stimulus environment of both speaker and listener, but only in so far
      as either their shape can be depicted by means of a mimed movement or their
      sound can be vocally imitated. With the introduction of symbolic
      representation reference is extended to absent objects, both individuals and
      kinds, to which a name has been assigned by the conventions of the language.
      With the introduction of syntax, particularly with the introduction of
      embedded clauses, it becomes possible to refer to absent objects by

      35. Before proceeding to detailed reconstruction of the evolution of
      language based on these principles, it will be helpful to review some of the
      evidence which supports the view that the freeing of the human forelimb from
      its locomotor functions, and the consequent development of manipulative
      skills, is as important for the evolution of language as it clearly is for
      the evolution of technology. The following pieces of evidence are relevant
      in this connection:


      36. Many birds have a vocal apparatus as good as that of humans; yet
      they have not developed language. This suggests that the crucial difference
      between birds and humans in this respect may be that, while both are
      bipedal, the forelimbs of birds are still specialised for locomotion, rather
      than, as in the human case, for manipulation.


      37. The occurrence of gesticulation as an invariable
      accompaniment of speech strongly suggests that gesticulation had a much more
      important role in the early stages of language evolution.

      38. Whenever vocal communication is blocked, either because it cannot be
      heard or, if heard, cannot be understood, human beings of every culture
      invariably fall back on gesticulation.


      39. The ease with which the deaf learn sign-language, particularly if
      brought up in an environment in which signing is in constant use by others,
      and the spontaneous development of homesigning by those who are not,
      suggests that the ability to use and respond to manual signs is an integral
      part of our human linguistic heritage.


      40. The practice of pointing with the index finger as a way of
      establishing reference to objects in the common stimulus environment of
      speaker and listener is a linguistic universal which by common consent plays
      an essential role in the acquisition of word-meanings.


      41. The earliest form of sentence seems to have been one in which the
      function (action) is indicated by means of a mimed movement and the
      arguments by pointing at the objects concerned. Communication which relies
      exclusively on sentences of this type constitutes a language of gesture
      (Piaget 1926/1932; Hewes 1973a; 1973b; 1976) on which human beings
      invariably fall back when vocal communication is blocked.

      42. The concentration of areas specialised for language in the same
      hemisphere of the cerebral cortex as that which controls the hand which is
      preferred for precise manipulative tasks demonstrates the intimate
      connection between the two functions (Cf. Hewes 1973b, p.9).


      43. There is a part of the human cerebral cortex, the angular gyrus on
      the dominant (usually left) hemisphere, which is specialised for deciphering
      linguistic stimuli in the visual modality (Thompson 1993, pp.399-402). Since
      writing and reading have developed far too recently and are still far from
      universal human accomplishments, the need to decipher a written text cannot
      explain the development of this ability to process visually presented
      linguistic signs. It must have been selected, probably before the
      development of speech, to facilitate the interpretation of a language of


      44. In a recent paper entitled 'Language in our grasp', Rizzolatti and
      Arbib (1998) have reached a similar conclusion in the light of
      evidence that Broca's area in the human left frontal cortex, long known as
      the area involved in the production and interpretation of syntactically
      articulated sentences, is homologous with an area in the monkey's brain (F5)
      where neurons (mirror neurons) have been found which respond both to the
      production of visually-controlled hand-movements and to the visual
      perception of the corresponding movements when made by others. Although
      Rizzolatti and Arbib do not make these points, it is evident that this link
      between the execution of a voluntary hand-movement and the visual perception
      of similar movements made by others is (a) a by-product of the visual
      feedback-control of voluntary movement, (b) the foundation for the ability
      to imitate the hand-movements of others without which a human technology
      based on the manufacture and use of tools would have been impossible, and �
      the foundation of the ability found, as we have seen, in chimpanzees to
      communicate by miming the action to be performed by the sign-receiver.
      45. No one would seriously dispute the claim that the earliest form of
      counting consisted in the practice which is found in every human culture of
      counting up to ten on the fingers of the two hands, and displaying the
      result to others by holding up the relevant number of fingers. This practice
      can, perhaps, be seen as an outgrowth of the ability to refer to objects by
      pointing at them. But since what is pointed at are the fingers rather than
      the objects being counted, this form of counting is an iconic representation
      of the number of the objects. Furthermore since you can only count things of
      a kind, counting presupposes a pre-existing ability to classify objects into
      kinds and, in the case of communicating the results of a count, a
      pre-existing ability to indicate the kind of object being counted. (I am
      indebted to Professor Robbins Burling of the University of Michigan
      [personal communication April 1998] for convincing me that, unlike vocal
      counting which is inevitably symbolic from the outset, digital counting,
      together with some written number systems such as the Roman before the
      practice of writing IV instead of IIII was introduced, is a form of iconic
      rather than, as I had previously thought, a form of symbolic


      46. The recent work on the process whereby arbitrary response-produced
      stimuli become symbols for (names of) objects, described in section II.XI
      above, argues for a key role in this process for the manual responses of
      pointing at and picking out the relevant stimuli.


      47. Little appears to be known about the process whereby action-names
      are learned. What is known (Khler 1921/1927) is that chimpanzees communicate
      what they want a conspecific to do by miming the action in question, and
      such miming is a conspicuous feature both of the gesticulation that
      invariably accompanies speech, unless the hands are otherwise engaged and of
      sign-languages, whether officially recognised or devised by the individual.
      This suggests that miming of the action by the caregiver and its imitation
      by the child must play a key role in the acquisition of action-names.


      48. In the light of this evidence and the principles outlined in
      sections I and II above, I would propose the following scenario for the
      evolution of what I am suggesting is the sequence of stages involved in the
      evolution of language:


      49. The first stage in the evolution of language appears to have
      occurred at a time when chimpanzees and humans had a common ancestor. Three
      interconnected abilities would seem to have developed at this stage: (a) the
      ability to use sticks and stones as tools and weapons, (b) the ability to
      imitate the movements of others in the context of learning to perform the
      manipulations involved in the effective use of tools and weapons, and � the
      ability to communicate what one wants someone else to do by miming the
      action required. There is some reason to think that the concentration of the
      manipulative and communicatory functions in one hemisphere of the cerebral
      cortex (the left in those who are right-handed) may have begun at this
      stage, perhaps with the specialisation of such structures as the angular
      gyrus and the pre-motor cortex in the dominant hemisphere for the visual
      interpretation of hand-movements in general and gesture in particular.


      50. The second stage culminates in the emergence of the first true
      sentences formulated in the language of gesture. It begins with the
      emergence of the practice of pointing referentially at objects, at the
      individual who is to do something, at an object to be manipulated, at a
      destination or location to which the individual is to move or to which the
      object is to be moved. As we have seen (Section II.IV above), this ability
      is lacking in chimpanzees, not because it is something they cannot learn to
      do, but because referential pointing is something to which, unlike dolphins,
      they cannot learn to respond. We have also seen reason to agree with Noble
      and Davidson's (1996) suggestion that this ability may have evolved with the
      development of the ability of a group of hunters to aim their weapons at the
      same target. Given the ability to use pointing to distinguish (a) who is to
      perform the action, (b) the object to be manipulated and � the individual to
      whom the object is to be transferred, it becomes possible for the first time
      in the history of communication between living organisms to construct novel
      sentences in what may be justly described as the language of gesture in
      which different mimed actions are combined with different combinations of
      argument (agent, object and recipient) identified by pointing at them.
      51. (Dr. Marina Sbis of the Department of Philosophy, University of
      [personal communication, June 1998], has drawn my attention to the
      fact that human infants frequently indicate the object to be manipulated by
      an adult, in the case of a small portable object such as a bowl, by bringing
      it to the adult or, in the case of a larger object by dragging the adult
      towards it. It is not clear to me whether this behaviour is part of the
      miming of the action to be performed which is already present in the
      behaviour of chimpanzees or whether it is a separate development, possibly
      connected to the technology of using containers to collect, store and
      distribute liquids such as water and milk and solids such as fruit and
      52. But significant though it is, the practice of referring to objects
      by pointing at them is severely limited in its scope. Whereas mimed action
      allows the communicator to refer to what has not yet occurred, the action to
      be performed by the respondent, referring to objects by pointing at them
      allows the communicator to refer only to conspicuous objects in the stimulus
      environment of both parties. The effect of subsequent developments is to
      increase that scope beyond what is indexically present.


      53. In Stage 3 vocalisation is added to the language of gesture. It
      depends on changes to the conformation of the mouth and larynx which are
      selected in the first instance by their effect in allowing human beings to
      imitate the sounds made, for example, by the male or female of the species
      to attract a potential mate, thereby enticing the latter into the traps
      which the technology provides. Once established such calls are introduced
      into otherwise gestural sentences as an alternative to pointing at instances
      of the object where no such instance is present. Since there is no obvious
      trace of the kind of iconic gestures used by homesigners to represent
      objects (Morford et al. 1993) in the gesticulations of those without
      auditory impairment, I am inclined to think that the vocal imitation of
      sounds made by animals were the first iconic representations of objects, as
      distinct from the iconic representations of actions by means of mimed
      actions which have been used since the days of our ape ancestors to
      represent the action to be performed by the sign- recipient. They make it
      possible for the first time to talk about absent objects as well as actions
      not yet performed.

      IV.iv. COUNTING

      54. The position of this fourth stage in the sequence of evolutionary
      events leading to fully developed language is unclear. It is placed here
      because it can be plausibly seen as the first step in the move away from the
      iconic towards a symbolic system of representation. It is the development of
      the ability to count up to ten on the fingers of the two hands and
      communicate the result by holding up the appropriate number of fingers.
      Considered as a representation of the number of objects in a group, holding
      up the corresponding number of fingers may be considered iconic. But, once
      they progress beyond the number of fingers on the two hands, counting
      systems inevitably become symbolic. Vocal counting is invariably symbolic
      from the outset.

      IV.v. SYMBOLS

      55. In Stage 5 the first representations of objects using arbitrary
      symbols (names) begin to appear. Once the use of symbols is well established
      in the repertoire of a human child, all that is required for the child to
      learn a new name or other lexical word is for the instructor to point to one
      or two instances of the kind of object the word is used to refer to while
      uttering the word in question. However, the evidence reviewed in Section
      II.XI above suggests that in its early stages learning the names of things
      is a much more complex process, one in which there is reinforcement both of
      the response of producing the name in the presence of an instance of the
      kind in question and the response of picking an instance of the kind in the
      presence of the name. Although apes, and possibly members of other animal
      species, can be taught to use symbols, they never progress to the point
      where there is spontaneous generalisation in both directions between the
      word or symbol and the natural signs of the presence of the object for which
      it stands. To be able to learn word-meanings as easily as a human child does
      from about the age of two requires a mutation which has occurred and been
      selected only in the human species.
      56. Apes who have been taught sign language or some other form of
      symbolic communication can construct sentences in what Bickerton (1990)
      calls proto-language. But without the rapidly expanding vocabulary that
      seems to develop only with the spontaneous emergence of stimulus equivalence
      classes, language can never take off as it does in the human child. Even
      so, consisting as they do entirely of names (lexical words), proto-language
      sentences have no syntax other than the verb/noun distinction. That, and
      perhaps some of the other distinctions that are later drawn by means of
      syntax, are indicated by gesture which, at this stage, still forms an
      integral part of the process of linguistic communication. This is the first
      stage in the evolution of language where the increased efficiency of
      language as a medium for interpersonal and intrapersonal communication is
      unquestionably what determines the selection of the mutation that provides
      it, rather than its utility in relation to some purely technological
      adaptation. It is at this stage presumably that Wernicke's area evolves as a
      centre for the interpretation and production of names. With the development
      of symbols (proper names) referring to particular persons and places,
      unambiguous reference to individuals in their absence becomes possible for
      the first time.


      57. As argued in Section II.III above, the developmental evidence
      suggests that the first sentences produced and responded to by our ancestors
      in the course of language evolution were all imperatives. It also seems
      likely that the earliest declarative sentences were answers to questions and
      that questions and answers evolved simultaneously as part of a single
      practice. As in the case of counting, it is unclear at what stage in the
      evolution of language this development took place. The best guess is that
      it was associated, as it seems to be in children, with the so-called naming
      explosion which occurs around the age of two or three and consists in a
      rapid increase in the child's vocabulary, particularly the names of kinds of
      object. This event appears to coincide with the child's discovery of the
      practice of asking questions of the caregiver, particularly questions about
      the names of things, a practice which, like the naming explosion it
      triggers, seems to be absent from the behaviour of the most intelligent of
      those apes who have been taught a form of sign-language.

      IV.vii. SYNTAX

      58. The development of syntax is the final stage in the evolution of
      language. It is selected by virtue of its effect in releasing linguistic
      communication from dependence on the listener's paying attention to the
      context of utterance and the gestures of the speaker in order to
      disambiguate what a speaker is saying. It thus allows speakers to talk
      intelligibly about situations which are not part of the current stimulus
      environment of either speaker or listener, whether in the past, in the
      future or at some place geographically remote from the context of utterance.
      Once it is fully developed, gesture, though still a valuable aid to the
      speaker's eloquence, ceases to perform any essential communicatory function
      as far as the listener is concerned. But, if gesture itself has been made
      redundant for all but the deaf by the introduction of syntax, it seems that
      the connection between language and manual and other forms of motor skill
      still survives in the remarkable parallel to which Horgan and Tienson (1996)
      have drawn attention between the syntactic organisation of sentences and the
      syntactic (no metaphor) organisation of a motor skill such as basket-ball
      59. It is an open question whether syntax evolved, as Chomsky would have
      us believe, through a single mutation, or whether the emergence of each
      class of syntactic operator required the selection of a separate mutation.
      In favour of the former view is the existence of a single area in the human
      cerebral cortex, Broca's area, which is specialised for its interpretation
      and production, damage to which appears to affect all types of syntactic
      operator more or less equally (Thompson 1993, p.398). In favour of the
      latter view is the observation that the order in which the different classes
      of syntactic operator are acquired by the child is a linguistic universal
      (Slobin 1985; Aitchison 1989). With the introduction of syntax,
      particularly the definite article and the relative clause, it becomes
      possible for the first time to refer to absent objects by description as
      well as by proper name.

      I am indebted for their stimulating comments and for additional
      references to Bernard Bichakjian, Paul Bloom, Rob Burling, Annabel Cormack,
      Tom Dickins, Heng-syung Jeng, Harry Jerison and Jill Morford. Since I have
      not otherwise cited his work, I should also express my indebtedness to Lev
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