4. Psycholinguisticstics

Psycholinguistics studies the mental mechanisms of language processing – speaking, listening, reading, and writing – both in a native and a second tongue. Psycholinguistics also studies the processes underlying acquisition of language, how language processes break down in language pathologies such as dyslexia (inability to read) and aphasia, and how these processes relate to brain function. Therefore, psycholinguistics overlaps with neurolinguistics.

The mind cannot be directly observed, so psycholinguists have to devise ways of finding out how it works. They get their evidence from two main sources: observation of spontaneous utterances, and psycholinguistic experiments. Since spontaneous utterances of ordinary speech are somewhat messy, in that there are dozens of different factors which have to be taken into account when utterances are analyzed, psycholinguists have to devise experi­ments in which the number of variable factors can be controlled, and the results can be accurately measured. But this type of methodology presents a problem, sometimes called the 'experimental paradox’. The more carefully an experiment is devised so as to limit variables, the more subjects are put into an unnatural situation, in which they are likely to behave oddly. On the other hand, the more one allows a situation to be like 'real life', the less one is able to sort out the various interacting factors. Ideally, major topics should be tackled both by observing sponta­neous speech and by devising experiments. And when the results coincide, this is a sign that progress is being made.

The three ‘core’ psycholinguistic topics are: ‘how humans acquire language’, how humans comprehend speech’, ‘how humans produce speech’. The first topic requires psycholinguistic evidence from child language, the other two topics involve the evidence mostly obtained from the language of adults.

4.1. Child language

Language acquisition by a child concerns such focal issues as (a) ‘growing’, or development of child language, (b) origin of language, (c) the rule-governed nature of child language, and (c) the way a child learns the meaning of words.

(a) ‘Growing’ of child language. Language is both nature and nurture, i.e. humans are naturally ‘pre-programmed’ to speak, but their latent language faculty is activated only if a child is exposed to actual input from a given language. Although the environments in which children acquire their language vary, they all go through similar stages in language acquisition that evolve during the same general time frame. Human infants pay attention to language from birth. They produce recognizable one-word utterances at around 12-15 months (girls may have an earlier start at 9 months). Their two-word utterances with content words such as nouns and verbs appear at around 18 months. Function words like ‘will’ and ‘my’ tend to appear after 24 months. And by the age of 3 years a child usually acquires the basic syntactic structures of the input language. Therefore, language has all the hallmarks of maturationally controlled behavior.

The goal of acquisition theories is to explain how it is that any normal child, born into any linguistic community, learns the language (or languages) of that community. For many theorists, the challenge is also to explain: (a) what appears to be the relatively short time period in which language acquisition is achieved, (b) the fact that language is acquired without either overt teaching or sufficient information from the input (what the child hears), and (c) to follow a path that seems remarkably similar in all children, despite variation in early childhood experiences and in the types of languages they are exposed to. There is also a consensus that language acquisition is largely independent of cognitive development, despite the fact that some deficits in cognitive development can have an effect on certain aspects of language development. Whether the language is a spoken language or a sign language, whether the language is highly inflected like Finnish or uninflected like Mandarin, whether the child is raised in poverty or luxury, by highly educated or illiterate adults, or even other children, it seems that normally developing children pass through roughly the same stages in the same sequence, and achieve the steady state of acquired language by about the same age.

The evidence from development of a child’s language strongly suggests that there is a ‘critical period’ for the first language acquisition, when the mechanism or mechanisms responsible for language development is/are primed to receive input. After the critical period, a person is unable to acquire language properly, which causes his/her mental deficiencies. The evidence is provided by the unfortunate natural experiments in which children were raised in isolation (or near isolation) from language-using older members of our species (i.e. they were severely neglected or were raised by other animals). With regard to the second language acquisition, the critical period is defined as ‘sensitive period’, during which a second language, as well as the first one, is learned by a child effortlessly and without instruction. The critical / sensitive period lasts from birth till 8/12 years of age (some scholars restrict it to 5 years of age and relate it to the period of lateralization, or formation of the basic neuron networks and specialization of the brain’s hemispheres). This period, in its turn, is further subdivided into sub-periods. The main ones are two: the period till 2/5 years is critical / sensitive for speech sounds (phonetics), and the period till 8/12 years is important for grammar. There is significant debate surrounding the issue of whether, when individuals learn a second language, they go about it in the same way as a first language learner, or whether it is a fundamentally different process. Evidence suggests that during the sensitive period children seem to be able to do acquite the second language much better than adolescents and adults.

Therefore, natural linguistic endowment and linguistic environment are both necessary for in language development. However, theories of language acquisition are distinguishable in terms of the relative contributions of these two aspects as the constituents of language ‘origin’.

(b) Origin of language. Some scholars emphasize the social aspect of language, and the role of parents. Children, they argue, are social beings who have a great need to interact with those around them. Furthermore, all over the world, child-carers tend to talk about the same sort of things, chatting mainly about food, clothes and other objects in the immediate environ­ment. Motherese or caregiver language has fairly similar characteris­tics almost everywhere: the caregivers slow down their rate of speech, and speak in slow, well-formed utterances, with quite a lot of repetition. People who stress these social aspects of language claim that there is no need to search for complex innate mechanisms: social interaction with caring caregivers is sufficient to cause language to develop. This latter view is turning out to be something of an exaggeration. The fact that parents make it easier for children to learn language does not explain why they are so quick to acquire it: intelligent chimps exposed to intensive sign language rarely get beyond 200 words and two-word sequences. Although children do not hear examples of every possible structural pattern, they nonetheless attain a grammar capable of generating all the possible sentences in their language (known as the poverty of the stimulus argument). And, although each is exposed to different data and in a different order, they all end up with the same basic grammar for their language, which would be unexpected under an imitative account. Less radical researchers, recognizing the role of inborn language faculty (nature) consider it to be less important than the role of input (nurture).

Another dimension of difference between theories concerns the innate aspects of language acquisition. This difference is known as content-process controversy. The realization that language is maturationally controlled means that most psycholinguists agree that human beings are innately pro­grammed to speak. But they cannot agree on exactly what is innate: they cannot decide to what extent (if any) language ability is separate from other cognitive abilities.

There are those researchers, most notably the generative linguists in a broadly Chomskyan paradigm, who argue for a dedicated language acquisition device (LAD), or the Universal Grammar that has evolved to serve the precise purpose of language acquisition. This device is primed specifically to receive linguistic input, and requires a minimal amount of it to set to work building mental representations for language in the mind of the child. The fact that the required triggering input is so minimal provides an explanation for the consistency of language acquisition paths across otherwise fairly widely varying life experiences. In other words, uniformity of speech development indicates that children innately contain a blueprint for language: this view represents a so-called con­tent approach.

Despite its power within linguistics, accounts grounded on the UG story actually attract only a minority of adherents within the broad field of child language research. Most researchers are convinced that language in its entirety can be worked out by the child on the basis of the input coupled with innate (nonspecific) predispositions for analyzing their environment. Children are innately geared to processing linguistic data, for which they utilize a puzzle-solving ability which is closely related to other cognitive skills. The ability to produce and comprehend language is just one of such skills. This conception is known as a process approach.

The whole controversy is far from being solved, though psycho­linguists hope that the increasing amount of work being done on the acquisition of languages other than English may shed more light on the topic. Some evidence relevant for it is provided by the rule-governed nature of child language.

(c) Rules of child language. Instead of learning language by imitating those around them, children create their own grammars. From the moment they begin to talk, children seem to be aware that language is rule-governed, and they are engaged in an active search for the rules which underlie the language to which they are exposed. Child language is never at any time a haphazard conglomeration of random words, or a sub-standard version of adult speech. Instead, every child at every stage possesses a grammar with rules of its own even though the system will be simpler than that of an adult. For example, children tend:

• to use negatives in front of the sentence: No play that. No Fraser drink all tea;

• to use the negative after the first NP: Doggie no bite. That no mummy;

• to use question word in front of a sentence: What mummy doing? What kitty eating?

• to form linguistic expressions by analogy, which results in the forms like mans, foots, gooses. Such plurals occur even when a child understands and responds correctly to the adult forms men, feet, geese. This is clear proof that children's own rules of grammar are more important to them than mere imitation.

The new constructions of child language appear at first in a limited number of utterances (What mummy doing? What daddy doing? What Billy doing?), and then gradually extend to other utterances (What kitty eating? What mummy sewing?).

Language acquisition is not as uniform as was once thought. Different children use different strategies for acquiring speech. For example, some seem to concentrate on the overall rhythm, and slot in words with the same general sound pattern, whereas others prefer to deal with more abstract slots.

(d) Learning word meanings. The most obvious semantic deviations of child language from the language of adults are undergeneralization and overgeneralization.

Undergeneralization means that a child associates word meanings with particular contexts; e.g. the word white is associated only with snow, but not with a piece of paper or color of a dress; the word car points to a toy, but not to a real car. The phenomenon of undergeneralization, which is caused by lack of abstraction in ontogenesis, is also found in phylogenies, when a language has names for, say, particular shades of red, and has no word for ‘red’ as a general hue that subsumes the shades.

Overgeneralization means that a child extends the meaning of a word from ‘a kind’ to ‘the type’; e.g. youngsters may call any kind of small thing ‘a crumb’: a crumb, a small beetle, or a speck of dirt; or they may apply the word ‘moon’ to any kind of light. Children's overgeneralizations are often quite specific, and quite odd because in categorization they may ‘work from a prototype’ that differs from that of adults.

In the course of language acquisition, overgeneralization along with generalization allows new knowledge to permeate across-the-board (from semantics to syntax and vice versa). This phenomenon of ‘bootstrapping’ allows learning in one area of language to trigger new learning in another. Semantic bootstrapping involves understanding an utterance in context and using it in conjunction with innate expectations of language principles to crack the code of the syntax. For example, a child who does not yet know the required complements of the verb ‘put’, can work these out from understanding utterances such as ‘Put the cup on the table’ in context. Syntactic bootstrapping involves working from an already understood structure to fill in meanings, semantic information, by deduction. For example, if you hear ‘John glopped his friend on the head and he fell down’, you may not know exactly what ‘glopped’ means, but you can work out a lot of what it must mean.

(+ Aitchison, p. 121-126)