15 THE CHALLENGE OF STUDYING LANGUAGE DEVELOPMENT IN CHILDREN

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15 The Challenge of Studying Language Development in Children With Autism Helen Tager-Flusberg University of Massachusetts Autism is a rare neurodevelopmental disorder of genetic origin. Among the primary characteristics of autism are impairments not only in language but also in communication. In this chapter I address the challenge of studying language development in children who lack the basic motivation to communicate with others, even when they may have acquired some linguistic competence. I begin with a description of the disorder and an overview of the kinds of language deficits that have been identified in autism. Then I take up different methodological approaches that have been used in research on language development in autism and discuss some problems encountered in using these methodologies. In the final section of the chapter I explore the possibility of using novel methods drawn from other research paradigms that may help shed further light on the mysteries of why children with autism seem to have such limited interest or ability to communicate with others.

WHAT IS AUTISM? Over 50 years ago Leo Kanner, an eminent child psychiatrist at Johns Hopkins University, first described a set of 11 children, all of whom had in common a core set of atypical characteristics (Kanner, 1943). These children were set apart from other children, including those with emotional disturbance or mental retardation, by their social withdrawal. They appeared to have little contact with others and little interest in people, leading Kanner to view “extreme autistic aloneness” as the cardinal feature of the new syndrome he had identified. Kanner noted a number of other major features of this syndrome, including obsessive insistence on routines and lack of change in the environment; deficits in language ranging from mutism to acquiring the ability to speak but using language in a somewhat meaningless and repetitive way; excellent rote memory skills; a variety of anomalous reactions to sensory stimulation; and sleep and eating problems. Although the children Kanner described were quite different from one another, in terms of both their current levels of functioning and their developmental histories, Kanner distilled from this diversity the core similarities that warranted a new diagnostic classification.

The essence of the syndrome captured by Kanner still rings true for clinicians and researchers today. Autism is currently classified as a form of pervasive developmental disorder of early onset, usually during the infant or toddler years. The three essential criteria for diagnosing autism include (a) qualitative impairments in social interaction. (b) delays and deficits in language and communication, and (c) restricted repetitive and stereotyped behaviors, activities, or interests (American Psychiatric Association, 1994). Within this “triad” of impairments symptom expression varies, depending on the severity of the disorder, the IQ level, and the age of the child. The majority of individuals with autism are mentally retarded; these children tend to be more socially withdrawn, have more stereotyped behavior patterns, are less communicative, and may have little or no functional language. Thus, in autism the overall level of cognitive ability is closely connected to social and language functioning. However, even in high functioning children serious limitations in social interest make the study of language acquisition difficult: There is often no interest on the part of children with autism to communicate with others or respond to others’ initiations, even when the children have acquired some linguistic ability. This is the challenge faced by researchers who wish to study language in autism. COMMUNICATION AND LANGUAGE IN AUTISM Parents of children with autism most often report that the first sign of a problem with their child is either the absence of language or the loss of language that had begun to develop in the second year of life (Kurita, 1985; Lord & Paul, 1997). Sometimes the initial concern may be that the child is deaf because they are so unresponsive to the voice of others including parents in their environment. In retrospect, many parents recollect that even during the first 12 months their infants were unresponsive to adult contact, did not engage in turn-taking games, and failed to develop joint attention (Volkmar, Carter, Grossman, & Klim, 1997). By their first birthday, many infants who later receive the diagnosis of autism do not respond to their own name and fail to make eye contact (Osterling & Dawson, 1994). By the end of the second year, toddlers with autism still have no functional language and are extremely limited in their communication with others, perhaps only engaging another person to fulfill requests using protoimperative gestures (Stone, 1997). They also do not engage in any symbolic play. To some extent, the primary social deficits in autism set the developmental course for deficits in language and communication there is simply no interest or “appetite” for interacting with others at any level or by any means, including language. Nevertheless some children with autism, usually those that are less severely impaired overall, do increase the frequency of their communicative attempts and begin acquiring language before their fifth birthday. Indeed, acquiring some functional language by age 5 has been found to be the most powerful predictor of a more positive outcome in autism (Rutter, 1970; Ventner, Lord, & Schopler, 1992). This group of verbal children has been studied by researchers using a variety of methodological approaches, some with greater success than others. The findings from many studies of children with autism have provided a general picture of the patterns of relatively spared and impaired capacities, as well as clinical descriptions of the most striking characteristics of autistic language.

Characteristics of Autistic Language Kanner (1943, 1946) was the first to note that children with autism often simply echo the words, phrases, or sentences spoken by others. This classical feature of autistic language, known as echolalia, is most typical of children who have very little productive language (McEvoy, Loveland. & Landry, 1988). Echolalic speech often retains the exact words and intonation used by others either immediately or after some time. It is now

viewed as having some functional value for children. Echolalia may help children with autism to maintain some role in the ongoing discourse even when they either do not understand or have not yet acquired the pragmatic or linguistic skills needed to respond more appropriately (Prizant & Duchan, 1981; Tager-Flusberg & Calkins. 1990). Kanner (1946) also noted the autistic child’s tendency to use words with special or unique meanings not shared by others. The use of idiosyncratic lexical terms, or neologisms, has been found even in higher functioning children and adults with autism (Volden & Lord, 1991), suggesting that it does not mark a developmental stage in acquisition. The source of these “words” and their function has not yet been elucidated. Another striking feature of autistic children’s use of language is their reversal of pronouns—referring to themselves as “you” and their conversational partner as “I.” Although reversing personal pronouns is not unique to autism, it does occur more frequently in this group than in any other population (Lee, Hobson, & Chiat, 1994) and pronoun reversals are viewed as important in the diagnosis of this disorder (American Psychiatric Association, 1994; Le Couteur et al., 1989). The reversals reflect difficulties in conceptualizing the notion of self and other as it is embedded in shifting discourse roles between speaker and listener (Lee et al., 1994; Tager-Flusberg, 1993, 1994). Autism has been identified as a language disorder that, at its core, involves pragmatic impairments (Baltaxe, 1977; Lord & Paul, 1997; TagerFlusberg, 1981a). Children with autism are often unresponsive to the conversational initiations of others. This has led many to question whether autism involves particular difficulties in comprehension (Paul & Cohen, 1984), although this has proven difficult to investigate using standard methods. Even when autistic children do engage and respond to others, they may offer little to the ongoing discourse, have difficulty sustaining the conversational topic, or offer irrelevant comments (Tager-Flusberg & Anderson, 1991). These discourse deficits are seen as central to the defining characteristics of autism (Tager-Flusberg, 1996); they parallel and are closely linked to the social and communicative impairments discussed earlier. All these features of language in autism—echolalia, neologisms, pronoun reversals, and pragmatic impairment—make it difficult to investigate language acquisition in this population. Indeed, the features have led some researchers to question whether autistic children develop language following the same pathways, and using the same underlying mechanisms, as do normally developing children or other children with delayed or deficient language (e.g., Simon, 1975). Nevertheless, over the past two decades psycholinguistic approaches have led to important advances in the study of language in children with autism. In the next sect ions I review some of this work, focusing on the methodological challenges that stem from the particular deficits that are central to this disorder.

STUDYING LANGUAGE DEVELOPMENT IN AUTISM The study of language in children with autism has been limited almost exclusively to those children who do acquire some functional language, either spoken or sign (cf. Layton & Baker, 1981). Moreover, because of the behavior difficulties experienced by many autistic children, studies have been further restricted to those who are more cooperative, less aggressive, or self-injurious. Because of the rarity of the syndrome and the inherent difficulties in conducting research with autistic children, most studies have included very small samples, sometimes just single case studies. These limitations mean that research in this area has not been able to capture the full variation that is known to exist in the population. There are also so few longitudinal studies that little is known about developmental changes occurring over the course of childhood.

Collecting Natural Language Samples In the field of child language, it is generally acknowledged that the richest source of data, especially on productive use of language, comes from spontaneous speech samples. These may be collected in different contexts as the young child interacts with some other person, either a researcher or familiar person such as the mother. This approach has been the most well utilized method for studying development in young children (cf. Brown, 1973). It is the most open-ended and least structured approach to studying language, which is often viewed as an advantage in that it allows one to view what children can do in a natural context without the external imposition of constraints or task demands that may not be understood by the child. But what might be viewed as advantages for the normally developing child—the absence of any external constraint—operates as a distinct problem for the child with autism. The lack of structure in which natural language samples are typically collected is an especially difficult context for children with autism. Given no constraint or external demand, the autistic child enjoys his or her own isolation and does not spontaneously socially engage with others or communicate much with them. This means that very little language might be gathered using this methodological approach, thereby making the collection of meaningful data very difficult. Children with autism do not spontaneously speak that much so the methods that involve the analysis of spontaneous speech may be of limited utility with this population. However, several studies have investigated the frequency of communicative acts in autistic children in different social contexts. These studies generally demonstrate that children with autism are sensitive to social context in ways that parallel those of very young normally developing children. Interactions with peers are the most difficult, even for high functioning older verbal children with autism. Stone and Caro-Martinez (1990) collected language samples from school-age children in their classrooms while they were engaged in free play or other informal activities. They also observed each child in their study for several hours, spread over a number of days. The average frequency of spontaneous communicative acts from the children with autism was just two or three per hour, mostly directed toward an adult. Only half their subjects ever spoke to a nonautistic peer In other experimental settings, such as the laboratory, other studies also found that children with autism speak much less frequently and use a narrower range of speech acts when engaged in free play (Landry & Loveland, 1989; Mermelstein, 1983). The effect of social context on the frequency of communicative acts in children with autism was systematically investigated by Bernard-Opitz (1982). She found that an autistic child was most likely to talk in a highly familiar setting with a highly familiar person. Furthermore, Bernard-Opitz found that in these social settings, at home with the mother, the autistic child produced more advanced language (i.e., more complex grammatical constructions) than in other social contexts. This means that laboratory-based studies using an experimenter as the primary conversational partner will not provide the most accurate portrait of the autistic child’s linguistic capacities. Taking these concerns into consideration, my colleagues and I conducted a small-scale home-based longitudinal study of language development in six young children with autism (Tager-Flusberg et al., 1990). Using both audio- and videotape, we collected hour-long language samples from the children as they interacted with their mothers in their homes, at bimonthly intervals. Data were collected in a similar way from six young children with Down syndrome who were matched on age and language level (assessed by mean length of utterance, or MLU) to provide a comparison group. As expected, the autistic children did speak less than the children with Down syndrome, even in this context. Nevertheless, we were able to collect sufficiently large language samples from all the children most of the time (usually well over 300-400 utterances) that would allow us to conduct meaningful analyses on developmental changes in syntax, morphology, and lexical and pragmatic functioning in these children. Our success was based, in part, on the children’s mothers, who knew that the focus of our research was language. The mothers worked hard at engaging their children in conversation, using many different approaches and activities to keep them talking.

New problems were encountered as we set about analyzing the transcripts we prepared from the taped language samples. The youngest children and those who were the least mature linguistically, not surprisingly, produced quite of bit of echolalia. The question we faced was how to handle these echolalic utterances in our explorations of grammatical and lexical development. We concluded that if we included echolalic speech we might overestimate the child’s linguistic knowledge. Maybe these children with autism echoed words they did not know, or maybe they were able to repeat utterances that were longer or more complex than they could produce spontaneously on their own. Although in normally developing children, imitated speech may also be more advanced than nonimitated, this poses little problem because it is so infrequent in their natural language samples (e.g., Bloom, Lightbown, & Hood, 1975). We also found that the autistic children would often recite speeches, count, or sing as a way of filling “air-time.” These learned segments of speech might also lead to the overestimation of the children’s linguistic knowledge. At the same time, other characteristics of autistic children’s language could lead us to underestimate their language abilities. In particular, we noticed that the children’s mothers asked many questions to which the children often gave single-word yes/no responses rather than an extended reply. These single-word responses and the use of stock social phrases (such as “please” or “thank you”) could lead us to underestimate MLU, the single most used measure of language development across a variety of populations (Brown, 1973; Miller & Chapman, 1981). Thus, the analysis of spontaneous speech data from children with autism clearly needed to be tailored to the particular features that are characteristically found even in relatively high functioning verbal children. We chose to handle these concerns by preparing a separate corpus of 100 child utterances from each transcript for both the autistic and the comparison children with Down syndrome. These corpora excluded all echolalic utterances, defined as all full or partial imitations or repetitions within live transcript lines. They also excluded routine phrases, singleword yes/no responses, and learned speeches or songs. Our analyses of these special corpora, that had eliminated the most problematic aspects of autistic language use, provided us with a rich and detailed picture of the development of language in this population (Tager-Flusberg et al., 1990). Contrary to claims in the literature that children with autism do not show a gradual increase in MLU or the same order for the emergence of grammatical constructions (e.g., Menyuk & Quill, 1985; Simon, 1975), we found that the developmental pathway for our autistic subjects was similar to what has been found for normally developing children. In fact, when we carefully examined echolalic utterances from the children with autism we found, surprisingly perhaps, that they were not developmentally more advanced than nonecholalic utterances from the same points in time. Echolalic utterances tended to be shorter and contain less complex constructions than spontaneously produced utterances (Tager-Flusberg & Calkins, 1990). These findings were taken as evidence that the underlying mechanisms for acquiring language were the same in children with autism, children with Down syndrome, and normally developing children. Despite the obvious surface and pragmatic differences in their speech, children with autism who do acquire language appear to depend on the same mechanisms and processes for developing language as do other children (cf. Prizant, 1983). In some, though not all, children, even the rate of development was similar to what has been found among normally developing children. Despite these challenges in both collecting and analyzing spontaneous speech samples, they have provided the richest and most accurate source of information on the development of communicative functioning (e.g., Coggins & Carpenter, 1981; Tager-Flusberg & Anderson, 1991; Wetherby & Prizant, 1990). Natural language samples have demonstrated the restricted repertoire of speech acts, as well as deficits in communicative competence, that are characteristic of children with autism. Other methods for investigating these aspects of language and communication are not available. Indeed, it is in this context of unstructured interaction that the autistic child’s communication deficits can be most clearly highlighted and explored.

Using Standardized Assessment Tools Often it is extremely useful to assess a child’s linguistic ability—in particular knowledge of structural aspects of language—using standardized instruments in order to address a number of research issues. Because these instruments tap a variety of domains, including phonology, semantics, lexical knowledge, syntax, and morphology, it is possible to explore the relation among these domains in both production and comprehension by comparing a child’s performance to age-based norms. This is, perhaps, the clearest way of examining the overall language profile in autism to address a number of interesting questions about the representation and processing of linguistic information. Such questions include whether comprehension is more impaired than production (e.g., Lord, 1985), whether lexical/semantic knowledge is more impaired than computational aspects of language (e.g.. Menyuk & Quill. 1985; Tager-Flusberg, 1981a), or whether language is more impaired than nonlinguistic cognitive ability (Lord & Paul, 1997; Tager-Flusberg, 1989). Answers to these kinds of questions may provide important information about the cognitivelinguistic phenotype of autism and how it compares to other groups of mentally retarded or language disordered children. Standardized tests are also often used to provide measures by which to match children with autism to control groups in more experimental studies of language or other aspects of cognitive functioning. The most widely used measure for this purpose is the Peabody Picture Vocabulary Test (PPVT; Dunn & Dunn. 1981, 1997), which provides a norm-based measure of receptive vocabulary. Some studies might also include a measure of syntactic comprehension, particularly if the experimental task requires the child to process complex linguistic information such as stories or scripts. Examples of tests that have been used to assess syntactic comprehension include different subtcsts on the Test of Auditory Comprehension of Language (TACL; Caaow-Woolfolk, 1985), the Test of Language Development (TOLD; Newcomer & Hamill, 1991), and the Clinical Evaluation of Language Fundamentals (CELF; Semel, Wiig, & Secord, 1995). Finally, it is important to keep in mind that standardized tests, such as the ones listed here, are most widely used in clinical settings to provide assessment of language abilities in children in order to inform treatment and intervention planning. These kinds of measures provide a particular set of challenges when they are used with autistic children. Psychometrically based instruments must be administered in a particular way by a trained individual if they are to provide valid and reliable data about language performance. But there may be difficulties encountered by the researcher in engaging the autistic child in the demands of a particular test. Generally, children with autism are not intentionally negative or noncompliant (Volkmar, 1987); rather, their lack of response to some standardized tests may be the result of not understanding the pragmatics of the testing situation. Typically, an unfamiliar person administers the test. As discussed earlier, the unique social deficits in autistic children might make them particularly unresponsive to the researcher in their presence. If more than one researcher is present, this might add to the autistic child’s anxiety. The environment itself may also add to the distractibility of the child with autism. Even when they are able to understand the test questions and have the requisite linguistic knowledge, children with autism may be quite unresponsive in an unfamiliar testing situation. Another concern that stems from the unique behavioral difficulties of autistic children is their tendency to perseverate, or repeat an action or response. Thus, if the answer to the first item on a task requires a child to point to a picture in a particular location—say, the first one on the left side of an array—the child with autism might continue to point to this location on all subsequent items. This kind of response may be produced not because the child does not understand the later items but because he or she is perseverating. Many tests of language comprehension involve pointing to pictures that correspond to words or sentences presented by the tester, so this kind of problem must be considered in evaluating responses given by an autistic child.

Tests of language production often have more complex pragmatic demands than do measures of comprehension. Not surprisingly, children with autism respond best to tests that require them to imitate or recall words or sentences spoken by the tester (or better still, presented on a recording), such as subtests on the TOLD. Yet these kinds of tests might not provide a particularly accurate measure on the child’s knowledge. Children with autism also respond well on confrontational naming tasks, which asks them to label pictures that are usually of concrete objects. But because they have difficulty understanding the more complex instructions for other kinds of semantic tests, autistic children usually perform worse on tests that tap relational or abstract meaning. Some researchers have taken this discrepancy in performance as a sign that autistic children have particular semantic deficits, which may or may not be warranted (Menyuk & Quill, 1985; Tager-Flusberg, 1986). Sentence completion tests or sentence formulation tests (which involve asking a child to create or complete a sentence using a word or phrase given by the tester) are often not easily completed by children with autism. Examples of this kind of test include the Formulated Sentences subtest on the CELF (Semel et al., 1995) and the Grarnmatic Completion subtest on the TOLD (Newcomer & Hammill, 1991). Autistic children may misunderstand the instructions and imitate what they have heard, rather than ending or formulating their own utterance. It is not clear whether this kind of response reflects expressive deficits or pragmatic problems in understanding the test instructions. All these variables, in addition to the fluctuating behavior and attention that is quite typical in autistic children may make it particularly hard to test them in a standardized way (Sparrow, 1997). Because standardized tests typically start with easy items and progress to more difficult ones, children with autism may also begin to experience frustration as they find themselves unsure whether they have answered correctly. Frustration can lead to tantrums or other behavior difficulties, which make it impossible to continue with the testing. On the other hand, one significant advantage of using standardized tests is that they are highly structured, which may help to maximize the performance of autistic children. Researchers can increase the likelihood that an autistic child will complete a standardized test in a relatively reliable way by making certain accommodations to the particular needs of the child. Using behavioral approaches to enhance the structure of the testing situation, including providing regular rewards (either tangible, such as food or tokens, or social praise) may be especially useful, particularly for those children who have had experience with these approaches in intervention programs or school settings. Providing frequent feedback and short breaks can also be helpful in keeping an autistic child engaged in standardized testing. Sometimes it is necessary to rephrase, simplify, or regularly repeat instructions, even though this is not strictly allowed by the standardized procedures mandated by a test. Even though these kinds of modifications might make the comparison of the child’s performance to the age-based norms questionable, it may be the only way to obtain any meaningful data from an autistic child on a particular standardized test (Sparrow, 1997).

Experimental Methods for Studying Language As is known from research on language acquisition in normally developing children, insights into the process and knowledge of children at different stages of development are best captured by experimental studies that use specially designed tasks and stimuli. Spontaneous speech data are limited by what the child actually produces; they do not reveal what the child may know but had no opportunity to use; they also provide only minimal information about the child’s comprehension of language. Standardized tests are designed to capture individual variation; they typically do not include a complete set of grammatical or morphological constructions, and often their item complexity is based more on informational load than on underlying grammatical complexity. Thus, standardized tests typically increase the length of sentences to make them more difficult or add more choices of responses; these are changes that add to the memory or attentional load of-the test rather than its linguistic complexity. Such tests

are not applicable to the study of the development of linguistic knowledge in all its richness. Experimental studies help to fill these gaps and have provided the detailed knowledge that is now available in the field of developmental psycholinguistics. There is no room in this chapter to cover the full range of experimental methodologies that have been used in the field of child language. Instead I cover just a few, to illustrate some of the unique issues that have to be considered by researchers who wish to employ experimental tasks with autistic children. In fact, there have been very few experimental studies of language processing published in the literature on autism (see Lord & Paul, 1997, for a recent review). Perhaps this is because the difficulties faced by researchers who wish to conduct such studies with this population have led them to seek alternative methods; this is especially true when one considers how hard it is to find a sufficiently large sample and the need to include matched control groups. Many experimental studies of child language, which typically target young normally developing children, make use of toy props to facilitate the interchange between the child and experimenter and to enhance the child’s enjoyment of the tasks. For example, many studies of language comprehension engage toy figures that the child must manipulate to demonstrate the meaning of a sentence. Studies that explore children’s grammatical judgments of sentences will often employ puppets that “speak” the correct or incorrect sentences. These methods take advantage of children’s propensity to engage in symbolic and functional play, especially with a variety of fictional characters participating in different activities. But the child with autism has no such propensity. One of the primary ways in which social and communicative deficits are manifest in autism is in the absence of spontaneous symbolic play (Sigman & Ungerer, 1984; Stone, Lemanek, Fishel, Fernandez, & Altemeier, 1990). These children do not play with toy objects in conventional ways and later on show no interest or capacity for role play (Volkmar et al., 1997). At the least, these deficits in play mean that autistic children may not have the same motivation and pleasure that other children find in the experimental tasks designed to tap linguistic knowledge. Of greater concern is that fact that for some children with autism, difficulties with these tasks may confound the absence of the linguistic knowledge embedded in the task with lack of understanding the representational value of the toys. If pictures are used to replace toys, then one must beware of perseverative responses, as discussed earlier. Stimuli for experimental tasks often depict animals as well as people, as if they were sentient beings. Researchers tend to imbue animals with human characteristics when interacting with children; story books are filled with these kinds of representations, and experimental tasks in child language research often do the same. This kind of representation assumes that young children have an implicit theory of mind: that they interpret action within a causal mentalistic framework (e.g., Wellman, 1990). There is considerable evidence that normally developing toddlers do infer that people are intentional and that their own and others’ behavior and actions can be explained on the basis of desires, emotions, and beliefs. By extension, within a play context, children also accept that other animals may also have minds and that their actions can be interpreted in the same way as those of human beings. But again, the use of these kinds of stimuli poses special problems for the child with autism. Indeed, autism is now viewed as a disorder that can be interpreted as involving core primary impairments in the acquisition of a theory of mind (Baron-Cohen, Leslie, & Frith, 1985; BaronCohen, Tager-Flusberg, & Cohen, 1993). Children with autism do not readily interpret their own or others’ actions in terms of mental states; they have difficulty even viewing people as intentional beings. The combination of deficits in theory of mind, and in symbolic play (which are likely to be closely connected: Leslie, 1987), make the use of stimuli that treat animals as if they were people especially problematic for children with autism. Many examples can be found in the psycholinguistic literature on the comprehension of grammatical constructions by normally developing children that use stimuli of this sort. For example, studies on the comprehension of relative clauses (de Villiers, Tager-Flusberg, Hakuta, & Cohen, 1979; Tavakolian. 1981), coordination (Tager-Flusberg, de Villiers, & Hakuta, 1982), passive constructions (Maratsos, Kuczaj, Fox, & Chalkley, 1979), and anaphora (Chien & Wexler, 1990) have all included anthropomorphic animals as the prime characters in the stories or sentences that

the children were asked to interpret. All these studies might be hard to replicate with autistic children because of the stimulus demands of the task. In considering experimental methods used to elicit different kinds of linguistic constructions, some of the same concerns that were highlighted for standardized testing may also apply. Children with autism may not understand the pragmatic demands of the task or the task instructions. Gamelike contexts that work so well for other children are not appreciated or even clearly understood by autistic children. They tend to repeat what the experimenter says, rather than complete or formulate their own response. If a child with autism is asked to describe an event enacted by an experimenter or depicted in a photograph or sequence of pictures that create a story, he or she is just as likely to simply name the objects (e.g., Tager-Flusberg, 1995) as to provide a narrative description. The problem lies in how to interpret this kind of response. Does it signal deficits in language, particularly in the ability to produce sentences, or is it the result of other aspects of the autistic syndrome? As a final example to illustrate the methodological challenges faced by researchers of children with autism, I discuss an early attempt I made to study grammatical knowledge in children with autism. As part of my dissertation research. I wanted to use Jean Berko Gleason’s famous wug paradigm to explore knowledge of grammatical morphology in children with autism (1958). Using the stimuli that Berko Gleason had created, and following her exact methods, I piloted this task on three children who clearly met criteria for the diagnosis of autism. I failed miserably! The children simply did not understand what I was looking for or what I was trying to do; they clearly viewed me as somewhat bizarre. As I explored the source of the problem, it became clear that the novel stimuli (wugs, ricking, etc.) were quite incomprehensible to the children. Children with autism are concrete and literal; they have no idea how to handle the invented imaginative forms and the creative methods that Berko Gleason so successfully used on normally developing children. Perhaps, had I persevered and worked out a modified approach, 1 might have been able to study autistic children’s knowledge of wugs with greater success. Instead, I addressed a different set of questions about sentence comprehension strategies, which turned out to be more easily implemented (cf. Tager-Flusberg, 1981b). To this day, there is no research on autism that has used the kind of elicited production methods that were pioneered by Jean Berko Gleason 40 years ago. CONCLUSIONS AND

FUTURE DIRECTIONS Studying language acquisition in children with autism is not an easy or straightforward task. Methodologies and stimuli have to be carefully selected, adapted, and modified to the unique set of deficits that define autism. Nevertheless, there has been some success over the past few decades in using certain approaches. Probably most has been learned about language development from the study of natural language samples. collected in different structured or unstructured settings. Standardized tests have also been used with some degree of success with higherfunctioning children. But as I have already discussed, these approaches are limited and can only address certain kinds of questions. Furthermore, all the research on language development in autism has been limited to the group of children who do acquire some functional language that they use spontaneously. Half the population does not (Lord & Paul. 1997). Questions remain about whether these nonverbal children understand any language and whether they perceive speech in the same way as other children do. It is not known whether the source of their difficulties with language stems from deficits in symbolic capacity, motivation to communicate with others, mental retardation, or a combination of all these factors. Until we as researchers begin to study these children, we will not achieve a full understanding of the language deficits that are central to the diagnosis of autism. Even verbal autistic children have been studied in only limited ways. There are too few longitudinal studies or experimental studies of either

comprehension or production. Some of the reasons for the paucity of research in this area have been discussed in this chapter. But if we are to make further advances, we will need to find ways of adapting our methods to address the unique demands and challenges of working with autistic children. Very different sorts of approaches will be needed to study verbal and nonverbal children with autism—in the same way as in the field of child language, different methods are used to study prelinguistic infants compared to toddlers and preschoolers who have begun acquiring language. One important way of addressing some of the challenges posed even by verbal children with autism would be to employ several different methodologies to investigate a particular set of research questions with the same group of autistic subjects. Using several methods simultaneously (e.g., standardized tests of language production, language samples, and elicited production methods) would help to minimize the problems found with each method used in isolation and would provide a richer set of data for analysis. The design of experimental tasks should take into consideration some of the concerns discussed in the previous section. The selection of standardized tests should also be made on the basis of which ones are best suited to this population. The multimethod approach would help to address some of the issues outlined earlier and provide researchers with a more complete picture of (a) how children with autism do acquire language, and (b) what accounts for their remaining deficits in communication, discourse, and certain aspects of language. What about nonverbal autistic children? Little is known about this group because so few research studies have focused on them. The combination of communicative, social, and cognitive impairments that define this group make them especially difficult to study. One strategy that has not yet received as much attention would be to employ the methods that define the field of behavioral analysis—the use of operant techniques. especially computer-based technologies, to study basic research questions about the underlying mechanisms that impede the acquisition of language in this population. Behavior analysis has been extensively used with this population, especially as a primary means for intervention (e.g., Can & Durand, 1985; Charlop & Trasowech, 1991; Harris & Ferrari, 1983). Thus, we know that operant methods can be successfully used, even as a means for assessing nonverbal autistic children (McIlvane, Deutsch, Serna, & Dube, 1988; Powers, 1988, 1997). But these kind of behavioral methods have not been used by psycholinguists in traditional research designs as a means for exploring basic questions such as whether nonverbal children perceive speech normally, or whether they understand words or grammatical constructions they do not produce. At the same time, behavior analysts who have employed these methods, usually in single case-study designs, have not used them to address the kinds of questions that psycholinguistics ask. It is time to consider integrating the methods and paradigms that have developed independently in the field of psychology, in order to address some of the fundamental questions about language and communication in autism (Wilkinson, Dube, & Mcllvane, 1997; Wilkinson & Tager-Flusberg, 1998). The methods that involve traditional operant conditioning techniques, including shaping the child’s response to ensure nonrandom responding, could be particularly successful because social motivation can be replaced with the use of tangible rewards and experimental presentation of materials can be accomplished via computers, thereby avoiding the social difficulties these children experience when interacting with a researcher. The future of research on language in autism will require the development of new approaches and methods that have the potential of avoiding many of the pitfalls discussed in this chapter. It is time for researchers in this field to follow the creative pathway forged by Jean Berko Gleason 40 years ago that has made much of the work in child language as we know it today possible. Although we may not be able to use her methods exactly, we must take inspiration from her efforts if we want to come to a deep understanding about the nature of language and communicative development in this unique population.

ACKNOWLEDGMENTS Preparation of this chapter was supported by grants from the National Institute on Deafness and Communication Disorders (RO1 DC 01234 and P01 DC 03610).

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