The rule system Essay Example for Free

The rule system Essay 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).  Childrens 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  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. Chomskys Universal Grammar theory was challenged by Tomasello (2000) who suggested a distributional explanation for childrens 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  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).