Self organisation “occurs when a structure emerges in response to a system’s dynamic interaction with an environment” (Mareschall et al. 2006 p. 192). Karmiloff suggests that the brain is a self organisation system. Donald Hebb’s (1949) influential work in neuropsychology supports this view. The Hebb rule implies that the more the neurones are activated the easier they then activate one another thus strengthening the neural pathways. This learning model can be applied to language; it strengthens through repeated usage (Mareschall et al. 2006).
To strengthen this theory it is worth noting that in a system as complex as the brain the infinite possibilities of outcome that may be produced is an indication of the impossibility of it being pre-specified (Elman et al. 1996).
It is important when debating nature vs. nurture to incorporate neuroscientific evidence.
Nativists argue that there is “an identifiable seat (for language) in the brain” (Pinker, 1994, p.45). Indeed the left temporal lobe has been unmistakably associated with language in adults however researchers such as Neville et al. (1998) have studied the concept of equipotentiality. This concept proposes that at birth each side of the brain has equal potential for developing language. The question for neuroscience lies in whether the left temporal lobe is critical for language development or if there are other cortical regions that can perform the task (Mareschall et al. 2006). The studies in this field draw conclusion that other cortical regions are able to support language however a full equipotential view is dismissed.
Neville et al. (1992) used ERPs (brain imaging technique) to suggest that grammatical and semantic information were responded to differently by the brain (Mareschall et al. 2006). He concluded with an epigenetic view stating that “there are constraints on the organisation of the neural systems that mediate formal language … however, it is clear that the nature and timings of sensory and language experience significantly affect the development of the language system in the brain” (Neville and Bavelier, 2001, p.283).
One aspect that nativists do not give much credit to is the plasticity of the brain. Cases of feral children such as Genie who were unable to learn language after having being isolated for many years support the nativits. However studies on localised brain damage that has occurred before or during birth have raised more challenges for language being innate.
The continuous functional recovery that is displayed after focal lesions and the brain’s ability to recuperate functional damage by other part of the cortex gives an outstanding example of how adaptive the brain is and a strong case against the brain being genetically pre-wired (Reilly et al. 1998).
Similar studies on temporal lobe damage carried out by researchers such as Stiles and Thal (1993) have given further neuroscientific support to epigenesis. Whilst
Mia Lherpiniere
X7374356
TMA 05
these studies do not dismiss the possibility of the left hemisphere being designated for language, they simply emphasise that “they are not critical since language can develop in a close to normal way without [them]” (Johnson, 1997, p. 142).
Looking beyond the biological argument the debate carries on through two propositions of how children acquire and produce grammar: single and dual route theory (Mareschall et al. 2006).
Children’s inflectional morphology follows a curved pattern which begins with correct application of outer layers; for example adding “ed” at the end of a word indicates the past tense. Inflections then become disrupted as grammatical rules are over generalised producing common errors such as “goed”. With experience children then seem able to apply regular and irregular forms of various tenses with ease. This pattern of development is called the U-shape (Plunkett and Wood, 2006). A conventional account for this process is that infants simply memorise the correct formation and as they discover grammatical rules they over apply them creating mistakes, then as the rules become more robust they eliminate the over-regularisations and adopt the correct format for nouns and verbs (Plunkett and Wood, 2006)
The competing theories differ in their account of how the memorisation and inflection process leads to the U-shape pattern of development (Plunkett and Wood, 2006).
Dual route theory has traditionally been associated with nativists such as Pinker (1988). The theory suggests that there is a memory system working in conjunction with a rule system. These two cognitive systems are activated when an individual attempt to inflect a word (Plunkett and Wood, 2006). The memory system, which they suggest keeps “a record of all the irregular and most common inflections” (Plunkett and Wood, 2006 p.182) is firstly consulted in an attempt to retrieve the appropriate formation. The rule system, which uses common rules of language to add endings to word stems, is simultaneously consulted to retrieve the appropriate ending. Should the memory system be successful in its search the rule system is prevented from proceeding (Plunkett and Wood, 2006).
The dual route theory explains the U-shape as a result of the memory system failing to retrieve the correct inflection and thus liberating the rule system producing an over-regularisation. With experience rare inflections are then solidified producing fewer errors.
The empiricist version lies with the single route theory which is supported by connectionist models who developed the same U-shape pattern of development and also “learned plural inflections before past tense inflections” (Plunkett and Wood, 2006, p.184) as infants do.
The theory holds that “regular and irregular inflections are produced by a single system that stores all of the inflections in the language” (Plunkett and Wood, 2006, p.183). Whilst connectionist networks can only serve as an indication of how credible
a theory is and not how such a process might occur, it is nevertheless a good reinforcement.
Single route theory proposes that the higher the numbers of inflections are stored in the memory the more intense the competition gets for memory space
Mia Lherpiniere
X7374356
TMA 05
resulting in what is known as the interference effect. This effect results in words with similar phonological sounds being confused.
Another connectionist model produced by Rumelhart and McClelland (1987) lent support to this theory. The first few verbs fed into the network were successfully conjugated but as more were introduced so the competition for network resources intensified and resulted in over-regularisation. Then through further training irregular verbs became engraved and mistakes diminished (Plunkett and Wood, 2006).
Other empiricists such as Marchman (1997) have produced evidence that favours single route theory by carrying out research that supports the prediction of which type of errors children are likely to produce. Marchman found that “irregular verbs with many enemies were more likely to have {add/ed/} wrongly used as their past tense form … than verbs that had few regular verb enemies” also “irregular verbs that had highly frequent past tense forms were less likely to be given the regular past tense endings than those verbs whose past tense form was rare” (Plunkett and Wood, 2006, p.187), this adheres to the single route theory.
Further support has been produced by cross-linguistic researches. Dual route theory serves as an efficient means for highly regular languages such as English. However for other languages such as German this is not the case nor is it valid for any language that has multiple ways of forming a tense.
Chomsky’s Universal Grammar theory was challenged by Tomasello (2000) who suggested a distributional explanation for children’s understanding of syntax. His approach places verbs in a prominent position as they place important constraints on utterances (Plunkett and Wood, 2006). Rather than memorising all utterances Tomasello suggests analogy; a partial remembrance of some utterances that are later adapted as prototypes for new utterances (Plunkett and Wood, 2006).
Early diary studies support this view. Brain (1963) made observations on his son through this early technique and observed that some words, which he called Pivot words only occurred in one position whilst Open words moved around freely. During the process of learning syntax, pockets of knowledge are formed; these then broaden allowing one another to influence each other creating grammatical regularities.
According to the distributional approach the explanation for recovering from over-generalisation is that as the pockets of knowledge become more robust they develop an ability to isolate which in turn reduces errors that may of occurred through either the “inappropriate extension of a pocket of grammatical knowledge or an attempt to resolve conflict between pockets of grammatical knowledge” (Plunkett and Wood, 2006, p.196).
Researchers such as Fodor and Karmiloff-Smith were a good representation of opposing views on brain modules. On balance the empirical evidence supports the epigenetic view of modularisation a process by which genes and the environment work together to create self organisation (Karmiloff-Smith, 1992). Neuroscience further supports a view in between nativists and empiricist, whilst they are able to produce evidence that the brain is capable of supporting language in other areas it is
unmistakable that damage to left hemisphere (the seat of language) can severely effect language development. How children acquire and produce grammar is debated
Mia Lherpiniere
X7374356
TMA 05
through single and dual route theory. Empirical evidence has given greater support to the single route theory which does not deny elements of nature but also incorporates
nurture. Connectionist networks are becoming a common method to test theories and have been used to lend support to many language theories such as the distributional approach.
Children through out the world inevitably learn their mother tongue whether it be by speech or sign (Karmiloff-Smith, 2002). What is substantive is whether this is due solely to operant conditioning of caregivers or to an innate principle of universal grammar. In view of the evidence presented in this paper it seems implausible that language can develop without the presence of both nature and nurture as Bruner (1983) conveys; “we shall make little progress if we adhere either to the impossible account of extreme empiricism or to the miraculous one of pure nativism.” (Bruner 1983, P. 10).
Word count 1987
Mia Lherpiniere
X7374356
TMA 05
References
Braine, M. (1963), cited in Oates, J. and Grayson, A. (2006) p.195
Bruner, J.S (1983), cited in Harris, P.L. (1992) p.3
Chomsky, N. (1965) Aspects of the theory of syntax, Cambridge, MA, MIT Press.
Elman, J. (1996), cited in Oates, J. and Grayson, A. (2006) p.133
Fodor, J.A. (1983), in Oates, J. and Grayson, A. (2006) p.128
Harris, M. (2006) “First Words”, in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/ The Open University.
Hebbs, D. (1949), cited in Oates, J. and Grayson, A. (2006) p.133
Johnson, M.H. (1997), cited in Oates, J. and Grayson, A. (2006) p.142
Karmiloff-Smith, A. (1992), cited in Oates, J. and Grayson, A. (2006) p.129
Karmiloff-Smith, A. (1992) “Reading B: Beyond modularity), in Oates, J. and Grayson, A. (2006) p.158-160
Marchman, V.A. (1997), cited in Oates, J. and Grayson, A. (2006) p.187
Marschall, D., Johnson, M. H., and Grayson, A. “Brain and cognitive development”, in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/ The Open University.
Neville, H.J. and Baverlier, D. (1998), cited in Oates, J. and Grayson, A. (2006) p.139
Neville, H.J. and Baverlier, D. (1992), cited in Oates, J. and Grayson, A. (2006) p.140
Neville, H.J. and Baverlier, D. (2001), cited in Oates, J. and Grayson, A. (2006) p.140
Pinker, S. (1994), cited in Oates, J. and Grayson, A. (2006) p.138
Reilly, J.S., Bates, E.A. and Marchman, V.A. (1998), cited in Oates, J. and Grayson, A. (2006) p.142
Mia Lherpiniere
X7374356
TMA 05
Plunkett, K. and Wood, C. (2006), cited in Oates, J. and Grayson, A. (2006) p.182-184 / 187 / 196
Plunkett, K. and Wood, C. (2006) “The development of children’s understanding of grammar” in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/ The Open University.
Quinn, P.C. and Oates, J. (2006) “Early category representations and concepts”, in Oates, J. and Grayson, A. (eds) Cognitive and Language Development in Children, Oxford, Blackwell/ The Open University.
Rumelhart, D. and McClelland, J. (1987), cited in Oates, J. and Grayson, A. (2006) p.185
Slater, A. and Oates, J. (2005) “Sensation to perception” in Oates, J., Grayson, A. and Wood, C. (eds) Psychological Devlopment and Early Childhood, Oxford, Blackwell/ The Open University.
Stiles, L. and Thal, D. (1993), cited in Oates, J. and Grayson, A. (2006) p.142
The British Psychological Society / The Open University
The Neural Network Booklet (2006) Open University.
The Study Guide 3 (2006) Open University.
Tomasello, M. (2000), cited in Oates, J. and Grayson, A. (2006) p.194
