The effects of reductionism
In every area of science there is an impetus to reduce the area of investigation to the smallest possible number of variables. Only in this way has it been possible to identify the components of the cell in biology or the elements of the periodic table in chemistry. But in the case of speech and language it is not obvious how to effect such a reduction.
There are medically diagnosable conditions inclluding Down’s syndrome, autism and cerebral palsy which selectively impede speech and language in different ways and to different degrees.
In the absence of any such diagnosis, the diagnosis of a disorder of speech or language can follow a number of directions:
- Factors listed in the Check list here – including the birth history, medical and emotional history, and whether or not there is another case of the same issue in thke immediate family:
- The anatomy and neurophysiology of the vocal tract; whether the sphincter separating the nasal cavity from the mouth is fully competent, whether or not there is an area of critically low sensitivity in the mouth, and more;
- Hearing; whether this has always been within what audiologists call ‘normal limits’ or whether there have been significant periods during which a child has had only limited hearing – typicalliy because of infection in respiratory tract;
- Attention; whether or not this can be held on whatever is interesting for the individual or whether this wanders continually and unrestrainedly;
- Auditory memory; whether or not a sequence of items can be repeated – in the case of numbers, normalliy up to seven; in the case of randomly selected items, typically less, depending on the complexity of the items;
- Auditory discrimination; how far a given signal can be successfully and acurately processed againsat a background signal of some sort or other; whether the words of a song can be made out against an orchestra or group;
- Alternating movenents of the articulators, known as ‘diadochokinesis’; lifting and lowering the protruded tongje seems like an exaggerated form of one speech movement. characteristic of almost all languages;
- Pragmatics; whether or not language is used appropriately;
- Vocabulary; how many words are known;
- Linguistics – syntax and semantics; h0w well is it undedrstood that sometimes referen,ce is sometimes allowed and sometimes disallowed, or by the very subtle Renfew Action. Picture Test, orby the Reynell Developmental Language Scales, or measured (very indirectly) as a Mean Length of Utterance, MLU; many authorities like to distingish between ‘productive’ or ‘expressive’ language and what appears to be understood;
- Phonetics – the speech sounds considered separately, as by various tests. such as the Edinburgh Articulation Test, EAT. designed on the basis of careful statistical control of the items, or as measured (very apporimately) as a Percentage of Cononants Correct, PCC;
- The organisation of the speech sound system, known as phonology, in a wsy that can only inferred indirectly from a test like the EAT;
- Metalingjuisticfs; the awareness that words can sound similar to one another, or that different words can mean almost the same thing; (true synonymy is raee; give and donate don’t mean quite the same thnng; donating means giving to someone or something with possibly more prestige than the giver. so the two words behave differently in the grammar in a way that has been much discussed);
- The will to communicate; whether or not there is this will and desire, or whether in the most extreme situation, there is just complete silence, now mostly known as ‘selective mutism’ – because in some caszes a child will only talk to one individual.
It’s a long list. Anatomy and neurophyisiology, hearing, attentiom. auditory memory and auditory discrimination, and diaxdochokinesis are clearly precoonditons. To varying degrees they can be reduced to numbers on scales. Hearing is conventionally measured frequency by frequency, two sets of numbers for each ear. An enormous volume of research has sought to disentangle the relative effects of these preconditional competences and how they interact. It is obvious that they are all relevant. But it is very unclear in this literature how far it can be determined that some particular level of any one competence is likely to be critical. And in the practical conditions of a clinic it is equally unclear how they can be accurately measured.
Pragmatics, vocabulary, syntax and semantics, phonetics and phonology, are clearly observable aspects of what Noam Chomsky used to call ‘linguistic competence’. Many psychologiests have, like Joan Reynell, devised tests of items which can be passed or failed, and thus given a numerical value which can be positioned with respect to a normal distribuition. But it is generally mysterious what this means other than an optimistic statement of intent. There is no known scale of linguistic competence. This is not to say that no such scale could exist. It just isn’t known.
Other items could be added under both headings. A list similar to this is given by many authorities. Some recommend checking off each of these items one by one. To my mind this is reductionism taken too far.
I personally like to start with what I can see or hear or what I am told about, mainly the linguistics, but without excluding anything else.
For instance, auditory memory and auditory discrimination often co-vary what is known as ‘Central Auditory Processing Disorder’ which in its most severe form is a profoundly disabling condition, but which also occurs in progressively more common symptomatolofies.
The advanatage of a lingujistically driven approach to diagnosis is that the symptomatology is described in terms of well-evidenced categories independently defined by normal speech and language. To my mind, this provide better, more precise guidelines for effective treatment than categories inferred from disorder.
Although the act of speaking is often to achieve some goal, to interest, to persuade, to endear, to get information, and so on, which may work or not work, as the case may be, the way we order the words is quite remote from any goal we have in the utterance in which these phrases occur. We say ‘good person’ and ‘someone good’ but not ‘person good’ or ‘good someone’., both almost uningterpretable. Person and someone are different sorts of words.
Similarly, want to shortens to wanna only if there is a following word. “Do you wanna go? Do you really want to?” The articulation of the T at the end of want and at the beginning of to looks forward to what is coming next. Such looking forward can’t be perceptual. And it isn’t plausibly motoric. Linguistic factors are forcibly involved. Children are normally learning about these seemingly small details at a very early stage in their acquisition of speech and language. If they aren’t, that is diagnostically significant.