Novel trips of infant tongue

Children's language problems are intriguing and often poorly understood by both lay people and those involved professionally in childcare. Such problems are also ill defined, identified essentially where the child has difficulties that are not commensurate with his or her overall mental ability, so that even prevalence cannot be calculated with any certainty. At the same time, language difficulties can be immensely disabling for children in terms of realising their educational potential. In a climate of regular assessment and school league tables, scant regard may be paid to the needs of the language-impaired child.

Shula Chiat attempts to clarify child-language problems, while giving an insight into the underlying deficiencies that give rise to the child's communication behaviour. The book will be of value to speech and language therapists, educational-needs specialists, and all involved in primary education. It is also accessible to those who may develop an interest through getting to know a language-impaired child.

Chiat dispels two common misconceptions. First, she makes clear that peripheral disorders, that is to say problems with either hearing acuity or movement of the speech articulators, do not account for the difficulties displayed by language-impaired children; these difficulties lie beneath the surface. Second, she emphasises that, while appropriate input to the child may help, it cannot compensate for a lack of the "sensitivities", through which the non-impaired infant tunes in to his or her language environment. This is the starting mechanism for language acquisition, and if it is intact, the child can overcome a less-than-stimulating environment and will still learn language. If it is not intact, the natural facilitating input that most adults use when talking to children will not prevent language problems.

The problem facing any language-learning child is clearly presented: how to match the sounds he or she hears to perceived events in the real world, in the absence of any communication system that will allow others to teach this explicitly. The solution is to look for something new in the environment whenever he or she hears an unfamiliar sequence of sounds and to listen for a new sequence of sounds when faced with something novel.

The notion of boot-strapping, that is the practical use of information from either the sounds, meanings or grammatical structures that the child already knows, to work out new uses of language, is introduced gradually throughout the book. At the same time, the consequences of having difficulties in processing information in any one (or more) of these areas are made clear.

Chiat takes the reader logically through the problems that emerge in learning words (both how to say them and what they mean); being able to use sentence structure to represent and understand the speaker's perspective on the event being talked about (crucial to distilling which features of a situation to communicate); and the use of unstressed, seemingly meaningless, grammatical inflections and function words that, nevertheless, are essential for communication. She shows how a logical sequence of psycholinguistic procedures can be used to tease out where problems lie. It is stressed that failure to perform a task may be the result of any number of causes, including boredom or a failure to grasp the instructions. When working with such children, one can be certain only about what they can do, not why they are unable to carry out certain activities.

The final chapters deal with children whose language may be relatively intact, but whose understanding of the world is so much at odds with those around them that their communications are perceived as bizarre. The same logical approach is applied to these cases, the autistic spectrum or so-called pragmatic disorders, although evidence for what is going on here is more sketchy, given the current state of knowledge regarding language in such children.

Whether or not researchers agree with the details of Chiat's approach, she presents the beginnings of a unifying theory that goes some way to explaining the frequently baffling combinations of problems that language-impaired children display. An important feature is her use of illustrations and extracts from interactions with children. Not only do these serve to illustrate problems, but they give insight into the intelligence, creativity and courage of these children.

Carolyn A. Letts lectures in the department of speech, University of Newcastle.