Methodological Issues

There are two broad and inter-related methodological issues. The first concerns the suitability of the self- understanding interview as an investigative tool for use with young people with autism. Given the abstract nature of the items that comprise the self-understanding interview, how sure can one be that the questions put have been understood? Does a non-response mean that the participant does not understand the question, that the notion of self is meaningless, or that she/he does not have access to language to provide a meaningful response? The second issue concerns the selection of a control group. Only by comparing and contrasting the performance of the young people with autism with that of adequately matched control subjects can meaningful statements about the abnormalities in the nature of their self- understanding be made. The issue of suitability of the self-understanding interview applies to both the index and control groups.

To respond meaningfully to the items of the self-understanding interview a person must understand the questions, recall from memory the relevant material, and have access to sufficient language to construct an answer. In addition she/he must be motivated to do this. Children with autism are known to have difficulties with the comprehension and expression of language, and memory. What follows is a brief review of the nature of these difficulties in young people with autism.

Language comprehension

Assessing the comprehension of children with autism is extremely difficult. Clinical observations highlight a marked lack of interest by children with autism in speech:

In the early years some o f the children show no response at all, even when their parents speak to them. They may later begin to understand a few single words which have specific associations. A t this stage, parents may complain that their child understands what he wants to, because they know that he responds when, fo r example, they say the words

chocolate or orange juice but ignores his parents when they give him instructions. Careful observation shows that the children's understanding is genuinely limited and that they have learned the meaning o f a few words through a process o f accidental operant conditioning because these words are closely connected with rewards, especially food. (p. 209; Ricks and Wing, 1975).

Further, those children with autism who demonstrate comprehension of speech may respond to questions in a concrete manner and limit themselves to the here-and-now. T h ^ have difficulty in understanding when asked to make a choice, and may automatically repeat the name of the last object mentioned whether they want it or not. Comprehension tends to be pedantic. They show confusion with idiomatic expressions, and have difficulty with understanding speech that changes with the context, such as pronouns and prepositions. Such words describe relationships rather than concrete objects or events.

How does this clinical picture compare with the findings from empirical studies in this domain? Beisler, Tsai and Vonk (1987) examined the comprehension of language in a group of 19 children with autism who ranged in age from 4 to 13 years and in non-verbal mental age from 3V2 to 10 years. ThQ^ were individually matched for chronological age, non-verbal mental age and sex with a group of children referred for suspected language delay. Both groups were administered the Test for Auditory Comprehension of Language (TACL: Carrow, 1973), which is used to assess receptive skills in morphology, syntax and vocabulary. The pattern of performance on this test was found to be comparable for both groups. This illustrates how language delay as well as deviance characterises children with autism, and that such abnormalities need to be taken into account when interviewing people with autism. In the present study the participants with autism were matched for receptive language ability using the British Picture Vocabulary Scale (BPVS: Duim, Dunn, Whetton, and Pintile, 1982). This test involves showing a series of plates in which drawings are arranged in groups of four. A word is presented and the respondent is asked to point to the drawing she/he believes accompanies that word. The BPVS, therefore, may also be considered a test of conceptual understanding, insofar as the subject must recognise the correspondence between the meaning of each word and the meaning of a picture. It may be that only a minimal understanding of the concept is needed to pass an item this scale, and for this reason Wheldall and Jefifree (1974) have criticised the use of the Picture Vocabulary Test as a measure of mental age in mentally handicapped populations: such individuals may attain higher scores

somewhat over-estimation of cognitive ability using the Picture Vocabulary Scale has also been shown in some young people with autism (Wetherby, Koegel, and Mendel, 1981; Tsai and Beisler, 1984). A mentally handicapped person's score on the BPVS, therefore, may be a conservative estimate of her/his limitations in understanding. While the matching of mentally retarded individuals with non-aged matched, normally developing subjects may be undermined because of this, the use of the Picture Vocabulary Scale to match two mentally retarded groups is not logically weakened.

Although the British Picture Vocabulary Scale is a test of single word comprehension, the studies of Rutter and his colleagues (Bartak, Rutter and Cox, 1975; Loclq^er and Rutter, 1970) indicate how the performance on this test compares with the verbal sub-tests of the Wechsler Scales of Intelligence in revealing 'troughs' in the abilities of people with autism. Clearly it does not provide a comprehensive measure of all aspects of linguistic understanding, but it has proved useful in a number of studies for establishing matched groups of autistic and non-autistic participants who then display similar levels of performance (although sometimes contrasting profiles of performance) on language-related tasks. It therefore seemed an appropriate matching procedure for the present purposes.

The issue now concerns the feasibility of matching individuals with autism, given their known proRle of linguistic and cognitive difficulties (Chapter Two), with same-aged non-autistic individuals using BPVS as a means of controlling for cognitive ability. Hobson and Lee (1989) individually matched 21 able young people with autism with non-autistic mentally retarded subjects for chronological age and performance on the BPVS. Independent raters coded the BPVS items for emotional, social, human and abstract content. Compared to control subjects, the autistic participants scored lower on emotion-related relative to emotion unrelated items, an effect that could not be attributed to the social content of the items. To underline the specificity of this finding the investigators also found that both groups achieved similar scores when responding to highly abstract relative to concrete words on the BPVS.

What are the implications of using the BPVS as a procedure to match autistic with non-autistic individuals? Comparable performance on the BPVS need not indicate that the matched groups are comparable on the general intellectual abilities that may be important for the demands of the task. A

given score may reflect very difierent processes underlying performance in autistic and non-autistic subjects, and such processes may be highly pertinent for the interpretation of results from the task (Hobson, 1991). There are two possible ways to reduce the possible impact of this problem. The first is to match subjects using more than one measure of cognitive abili^ pertinent to the demands of the task (Tsai and Beisler, 1984) as in, for example, some measure of expressive language. This point will be discussed further in the following section. The other way of reducing the impact of this problem is to design control tasks that are comparable to the index tasks in terms of their level of difliculty, but differ in their focus of inquiiy. For example, an appropriate control task in the self-understanding interview may be to compare and contrast the linguistic and conceptual complexity of verbal responses to questions put to the child about the moral workings of the world, devoid of self-understanding. If the index group perform as proficiently as the control group on the control task, but perform less well on the index task, then one would have reasonable evidence for a specific deficit in the index group. Although the current study did not benefit from such a control, it was intended to examine the pattern of responses within the self-understanding interview, to see if this revealed evidence for or against the possibility that some non-specific affect of difliculty with 'abstraction' might be a factor in producing the group contrasts observed.

Language expression

One major flmction in the use of language and non-verbal gesture is to communicate with others, as reflected in the pragmatics of language (Bates, 1976). Children with autism who come to use language are generally impaired in the pragmatic aspects of their language. They may, for example, fail to shift appropriately ft'om hearer to speaker role, not understand the social rules governing what is acceptable in a conversation (turn taking, asking personal questions in an impersonal context), and use a style of speech that is monotonous and pedantic. Tager-Flusberg (1981) concluded that phonological and syntactic development in children with autism, though delayed, follows the same course as normally developing children, though the semantic and pragmatic functioning is deviant. In a later study by Tager-Flusberg (1985), children with autism were compared ^ t h verbal mental age matched controls. The investigator found that while the representation of semantic knowledge in children with autism did

not differ significantly from the control group, the pragmatic aspects of speech did significantly discriminate between the groups. Thus the pragmatic deficits appear to be the main area of deviance in the language of children with autism.

In general, production skills may be more advanced in children with autism than their comprehension skills (Tager-Flusberg, 1981). Here, too, however, one observes a complex mixture of abilities and disabilities. For example, Boucher (1988) examined the performance of seven high-functioning children with autism, ranging from just under 12 to 16 years of age, on tests of word fluency. Participants were asked to name as many words in the space of one minute in each of four categories: (a) colours; (b) animals; (c) foods; and (d) as many words as they could think of, termed 'miscellaneous'. Boucher found that the performance on the three familiar categories was comparable to that of a matched control group. On the miscellaneous word generation, however, the performance of the children with autism was significantly below that of the control group. This was accounted for by the fact that the control group did well on this task relative to their performance on the familiar categories, as opposed to the study group performing less well than on the familiar categories.

It is important, therefore, to evaluate whether abnormalities in children with autism in generating language might contribute to group differences in their responses during interview. This was controlled by matching the young people with autism for their mean length of utterance (MLU). The MLU is considered a general indicator of linguistic ability, and correlates highly with more sophisticated measures of syntactic complexity in expressive language (Jaedicke, Storoschuk and Lord, 1994).

Memory

Once again, children's responses during interviews may be influenced by their abilities in remembering things. Boucher (1981) compared the memory for recent events in a sample of 10 high-functioning children with autism who ranged from 1016 to 16 years of age. In a standard procedure the participants were presented with four paired associate lists, allowed to play with a combination-lock money box, conduct a forced choice face recognition task, partake in a mock football game, allowed to play with a

box camera, and finally to draw a picture of their own choice. After a short delay each child was asked what they remembered doing in the room with the experimenter. The children with autism recalled an average of two items. This was significantly less than the average 3.7 items recalled by their matched control group. The significant différence remained when the superior performance on the verbal comprehension test was statistically controlled for. As an aside, however, Boucher does mention that

autistic children's cued recall was good (p. 299). It is important, therefore, that the present methodological approach include efforts to cue participants in their responses to questions during the self-understanding interviews. As described above, the self-understanding interview has been designed to explore the reasoning or grounds for any self-statement elicited. It is assumed that the prompting of first responses will serve to cue the participants in the recall of the relevant material.

Motivation

The final methodological issue concerns the motivation of participants. O'Dell, Dunlap and Koegel (1983 - reported in Koegel and Mentis, 1985) compared the impact of two reinforcement contingencies on the verbal responding of four children with autism. They found that compared to a schedule of reinforcement targeted to specific verbalisations, when any observable attempt to verbalise was reinforced all children achieved higher rates of correct verbal responding and progressed more rapidly. The results suggested that by reinforcing communication attempts, the children's motivation to maintain interest and attention in a task may be increased. The investigator knew all the participants well, having worked with the individuals in both the study and control groups for at least four years, and some of the young people with autism longer again. Each person who took part in this study was judged to have maintained their attention and motivation to participate throughout. The interviews were paced according to the participants' needs and routine, and stopped at the first signs of waning attention. As far as possible, therefore, steps were taken to ensure that the responses provided by the participants reflected their considered understanding of self.