Closely connected

Photo by Sudhamshu Hebbar on Flickr [CC BY 2.0]

An article written by the British linguist Vyvyan Evans entitled “Language Instinct is a Myth” which I shared on Twitter the other day triggered a lively discussion with my colleagues. One of the questions raised on Twitter was how come the idea that we are born with a built-in language capacity (aka the innateness hypothesis) has prevailed for so long and Chomsky, its main promoter, is part of all Master's in TESOL programmes if the theory has largely been discredited (Scott Thornbury asks the same question on his in X is for X-bar Theory).

This was indeed the case on my MA programme: Behaviorism and Chomsky took up a large part of two of my Psycholinguistics courses while such a fascinating, more recent theory as Connectionism received scant or almost no attention. Now that I am on the giving end, i.e. giving rather than listening to lectures, I was also surprised at the lack of references to Connectionism in an SLA course syllabus which I inherited (and revamped completely). Chomsky, on the other hand, is such an enduring staple of TEFL/TESOL courses that even BA students come to the course already knowing him – or at least having heard his name.

For an overview of Chomsky's theory see THIS POST by Geoff Jordan or THIS POST by Kylie Barker.

Connectionism is also conspicuously absent from Vyvyan Evan’s criticism of Chomsky although it provides much a stronger argument against the innateness hypothesis. What is Connectionism and how is it connected to this blog?

It doesn’t sound right but I can’t explain why…

The word “grammar” usually conjures up in the learner’s – and teacher’s – mind images of verb tables and rules which can be memorized and tested. Indeed, some rules – or rather rules of thumb – exist and can be called upon when punctuating a sentence (add an apostrophe after plural nouns ending with –s) or spelling a word (“i before e except after c”). Learners can be given useful rules such as: We add –s/-es to make the plural form or most nouns or add –d/-ed to make the past tense of regular verbs. The rules that can be formulated and verbalized are known as explicit rules. A greater number of linguistic rules though – probably much greater than explicit rules – are implicit rules, i.e. rules which competent language users (not only native speakers!) know but cannot express verbally. The knowledge of implicit rules is evident when we can tell if a sentence is correct or incorrect just because it sounds right. This intuitive feel for grammaticality, however, has nothing to do with the sixth sense; it has sound psychological foundations.

Artificial neural networks (explained as simply as possible)

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The human brain is made up of a massive number of neurons meshed into complex networks. In order to understand how information is stored across neural networks of the brain, artificial neural networks can be created on the computer. Artificial neural networks simulate how the brain functions when processing information and consist of many units (representing neurons) and their connections (representing synapses), hence the name “connectionism”.

Already in the 1980s, connectionist experiments shed considerable light on the processes underlying human cognition and, specifically, language acquisition. For example, a computer simulation created by Rumelhart and McClelland (1986) was “trained” to predict irregular past forms of the verbs it had not previously encountered. For example, after the network “learned” that found is the past form of find, and bound is the past of bind, the network would produce wound in response to wind.

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Now on to something truly phenomenal. Neural networks have been shown to exhibit the same “faulty” behaviour as humans. The next set of verbs which was fed into Rumelhart and McClelland’s network consisted of both irregular and regular (-ed) verbs. As the number of regular verbs began to grow, the network started to produce errors such as *broked instead of broke or *taked instead of took. But after more training, regular and irregular verbs fell into place as the network recovered and started producing correct forms again.

As you probably know, this process is very similar to the developmental stages language acquirers – mainly native speakers but also L2 learners – go through. Initially they produce correct irregular forms, such as went and took, but, as encounters with regular verbs become more and more frequent (washed, cleaned, started, finished), they backslide to *goed and *taked. Chomskyans would, of course, explain this as learners starting to grapple with the rules of the past simple and overgeneralising them to irregular verbs. But Rumelhart and McClelland’s neural network displayed the same psycholinguistic phenomena as overgeneralization and backsliding – in the absence of any grammar rules! 

Rules or connections?

Connectionists offer a simple but compelling explanation of this phenomenon: the neural network learned the pattern on which the past tense is formed as a result of exposure to linguistic data. Regular verbs showed such a strongly consistent pattern in the input that the connections formed between units in response to regular verbs outweighed all the connections activated by irregular verbs.

Posing a radical challenge to the classical rule view of language, connectionism posits that language learning has nothing to do with learning rules, although language behaviour may ultimately appear to be rule-governed. Just like the artificial network was not taught the rules of the past simple, mental representations of rules need not be present in explicit form anywhere in the brain. According to connectionism, language acquirers merely form mental associations between various elements (phonemes, morphemes, words etc) which frequently occur together in language input.

Connectionism and lexical chunking

You are probably wondering what it all has to do with this blog. In fact, connectionism and its younger brother “emergentism” are compatible with the idea of lexical chunking and provide a solid psycholinguistic base for the Lexical approach.

• Chunks consist of words that often go together:  of course, I hope so, to make things worse, it’s been a long time since…, i.e. they are frequently co-occurring elements in language 
• Learning a language is not a matter of mastering explicit grammar rules as I have argued HERE
• Learning chunks can help establish important patterns which pave the way to grammar acquisition - see HERE
• Repetition plays a crucial role – learners need multiple exposures to “strengthen the connections” between co-occurring elements
• Although explicit teaching of grammar rules does not result in implicit knowledge it may speed up the process of grammar acquisition through noticing

So, to return to the discussion with my fellow professionals on Twitter: should Chomsky be banished from TESOL programmes’ syllabi? Certainly not. As a starting point in SLA research it merits analysis and discussion. Without understanding Chomsky’s Universal Grammar hypothesis, it would be hard, for example, to explain Krashen* or to grasp the significance of the nature vs. nurture debate as regards language acquisition. But the question remains why Chomsky's view has dominated the field for so long. Is it because, as Vyvyan Evans claims, it's simple?

What do you think?

References

Rumelhart, D. E.,& McClelland, J. L. (1986).On learning the past tense of English verbs. In J. L. McClelland, D. E. Rumelhart & the PDP Research Group (Eds.), Parallel distributed processing: Explorations in the microstructure of cognition, Vol. 2: Psychological and biological models (pp. 216–271). Cambridge, MA: MIT Press.

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* Interestingly - and perhaps ironically - Michael Lewis draws heavily on the work of Krashen, who is clearly a Chomskyan