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CLINICAL LINGUISTICS & PHONETICS, 1996, VOL. 10, NO. 4, 28 1-298
A linguistic account of a developmental, semantic-pragmatic disorder: evidence from a case study
DAVID S N O W Child Language Center, University of Arizona, Tucson, AZ 85721, USA
(Received I December 1994; accepted 25 April 1995)
Abstract
This is a clinical case study of a 4-year-old boy (H.N.) who demonstrates an infrequently studied ‘semantic-pragmatic’ type of specific language impairment (SLI). In contrast to the disturbances of linguistic form that characterize the most frequently reported type of SLI, the semantic-pragmatic syndrome is charac- terized mostly by ‘inappropriate’ language use. A cognitive explanation has been proposed that accounts for all instances of inappropriate language thus far studied in this population. An expressive linguistic explanation has also been proposed that accounts for some instances of inappropriate language, but not for irrelevant comments or inappropriate responses to questions. I propose that a receptive linguistic explanation can account for inappropriate responses to questions. Thus, a linguistic explanation with receptive and expressive components could account for all but a few semantic-pragmatic behaviours previously accounted for by the cognitive explanation. To test this proposal, H.N.’s responses to questions were studied in relation to the interrogative forms (Wh-words) used in the questions addressed to him. The results indicate that H.N. failed to comprehend a specific Wh-word that was associated with a set of relational concepts, but he understood other words that expressed an overlapping set of concepts. Thus, instances of inappropriate language use that appear to express disordered concepts may reflect receptive linguistic deficits instead. To the extent that these findings can be extended and replicated, they suggest that the semantic-pragmatic type of SLI is closely related to the type of SLI that affects morphology and syntax. The pos- sible unity underlying the two types of SLI is discussed in relation to a phono- logical storage/access theory that has recently been proposed to account for morphosyntactic deficits in preschool children with language disorders.
Keywords: semantic-pragmatic disorder, developmental study, child language.
Introduction
Children with specific language impairment (SLI) are identified broadly as having composite scores on non-verbal cognitive measures that are within normal limits, but scores on language measures that are low relative to age norms. Specifically, Leonard (1989) proposed that children with SLI have difficulty with a wide range of language skills, and special difficulty with morphosyntax. Researchers who have identified subtypes within SLI have called this syndrome ‘phonological-
0269-9206196 $12.00 0 1996 Taylor & Francis Ltd.
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syntactic” (Bishop and Rosenbloom, 1987; Rapin and Allen, 1983). Children with morphosyntactic deficits, including children whose language disorder is described as phonological-syntactic, have a good understanding of concepts, but express their ideas with linguistic forms that are not age-appropriate. In this paper the com- bination of appropriate concepts and impaired linguistic form is referred to as a linguistic deficit.
In line with classification approaches that allow for subtypes of SLI, researchers have also described children whose language behaviours are different from the morphosyntactic profile. A notable example is a child who seems to produce phonolo- gically and syntactically well-formed sentences but has apparent difficulty with the meaning and use of language; thus the syndrome is called ‘semantic-pragmatic’ (Bishop and Rosenbloom, 1987; Rapin and Allen, 1983). Bishop and Rosenbloom report that children with a semantic-pragmatic disorder have subtle problems with language form, such as incorrect lexical and pronoun choices, but that the most outstanding characteristic of such children is their production of bizarre comments and tangential or irrelevant responses to questions. As a result their language use leads to listener impressions of ‘inappropriateness’ (Bishop and Adams, 1989).
Rapin and Allen (1983) pointed out that it is not known to what extent inappro- priate language reflects a ‘thought disorder’ (what I refer to as ‘cognitive deficits’) in addition to a ‘communication disorder’ (what I refer to as ‘linguistic deficits’). Cognitive deficits refer to problems with concepts, or the content of language. Linguistic deficits refer to problems with linguistic form-that is, the pairing of form and concepts. Bishop and Adams (1989) addressed the same question posed by Rapin and Allen, and illustrated the distinction between linguistic and cognitive deficits by using the following example from the conversational speech of a child with a semantic-pragmatic disorder.
(1) We went on a bus because Lee was sick out of the window.
The inappropriateness of this sentence arises from the odd use of because (note that and would have been more appropriate). One possible cognitively based explanation would be that the child has a faulty understanding of causal concepts. That is, he really thinks that Lee’s sickness was the cause of the bus journey. In this interpreta- tion the child’s concepts would be implicated as the source of the inappropriate word choice (a cognitive deficit) rather than linguistic form (a linguistic deficit). For this reason Bishop and Adams (1989) observed that examples such as ( 1 ) may be construed as ‘ostensible evidence that the child is thought-disordered or psychotic’ (p. 261).
Alternatively, Bishop and Adams suggested that the child may realize perfectly well that the bus trip was not caused by Lee’s being sick, but does not realize that because conveys a different meaning from and. They interpret this possibility as evidence for semantic overextension of the word because. Bishop and Adams pointed out that a linguistic explanation may lead to an interpretation of a child’s inappropri- ate language use that is less extreme than the conclusion that the child has a thought
In light of evidence that phonological disorders are variable with respect to the presence or absence of concomitant deficits in morphology and syntax (Paul and Shriberg, 1982), I will use the term ‘morphosyntactic’ to describe the language disorder that Leonard refers to broadly as ‘specific language impairment’ and Rapin and Allen (1983, 1988) refer to more narrowly as ‘phonological-syntactic’.
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Linguistic account of a semantic-pragmatic disorder 283
disorder or psychosis. In this paper I suggest that the use of because illustrated in ( I ) simply indicates that the child has selected an incorrect form.2 This version of the linguistic explanation implies that the child’s concepts are appropriate but he has difficulty selecting the correct linguistic form to convey the intended meaning.
Bishop and Adams (1 989) referred to another category of inappropriate language which they characterized as ‘unusual or socially inappropriate content or style’. Instead of utterances such as (1) that reflect possible form problems, utterances in this second category are inappropriate because of their bizarre content. They are typically described as tangential, irrelevant, or even non-related to the topic, and are exemplified by seemingly irrelevant responses to questions. An example cited by Rapin and Allen (1983) is shown in (2).
(2) Adult: Where do you go to school?
we have different teachers ... Child: Tommy goes to my school because I see him every day in the hall, but
In this example the child has difficulty with the same word (because) that was discussed in (1). However, the oddness of the response is owing mostly to the absence of its logical connection with the preceding question. Rapin and Allen ( 1983) suggested that inappropriate language exemplified by (2) could reflect a thought disorder (cognitive deficits) in addition to a communication disorder (lin- guistic deficits), but they did not attempt to elaborate further. Bishop and Adams ( 1989) suggested that cognitive deficits could account for such types of inappropriate language, but they did not propose an alternative linguistic explanation. In fact they concluded that such instances of inappropriateness are not easily explained in linguistic terms. In summary, a cognitive explanation has been proposed to account for instances of inappropriate language exemplified by (1) and (2), whereas a specific linguistic explanation has been proposed to account only for examples like (1).
However, I propose that a linguistic explanation for (2) is feasible, given two assumptions. First, it is possible that the child’s inappropriate response reflects poor comprehension of the eliciting question. Second, since comprehension involves both concepts and words, it is possible that the comprehension breakdown reflects the child’s inability to properly interpret particular words in the adult’s question, for example, the pronoun where. The reader will recall that the linguistic explanation for (1) is that the child has difficulty selecting particular linguistic forms. Thus, the linguistic explanation for (2) is the receptive analogue of the expressive explanation that was proposed for (1).
This case study was designed to determine whether the linguistic hypothesis warrants further investigation in studies of this population. The method used in this investigation is to examine linguistic evidence derived from analysis of a question- and-answer interaction between an adult and a child with a semantic-pragmatic disorder. The goal at the heart of this method is to identify two or more words or phrases in the adult’s questions that convey an overlapping set of concepts (different forms, similar concepts). For example, the forms where in (3) and what ... on in (4) both express the concept of [LOCATION] (in the following discussion, concept names are printed in small capitals within brackets and linguistic forms in italics).
In the discussion section, a dual-pathway interactive model of word retrieval supports the proposal that word-choice errors could reflect semantically related substitutions under conditions of weakened phonological processing.
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Relational Linguistic Cognitive Linguistic - FOrm Hvwoth esis 1(Yvothes& - where
[LOCATION] A -
----+ {in, on) NP - +
Figure 1. Predictions by two theories about the association between linguistic forms and a high frequency of inappropriate responses ( -) or low frequency of inappropriate responses 7 + ) to questions (the notation {in, on} N P = in or on plus a noun phrase, pronoun, or Wh-word, e.g. what).
( 3 ) Where is that frog? (4) What is that frog sitting on?
Once the analysis has identified different forms for analogous concepts, the linguistic and cognitive hypotheses can be evaluated because the two hypotheses lead to different predictions about the consistency of the child’s apparent comprehen- sion of different words expressing similar concepts. These predictions are sketched in Figure 1, using the examples in (3) and (4). In the figure a high frequency of appropriate responses is taken as evidence for comprehension of the target word or words (plus sign) and a low frequency of appropriate responses is taken as evidence for poor comprehension (minus sign).
To account for inappropriate responses like (2), the linguistic hypothesis posits that the child understands the underlying concept [LOCATION] and predicts that he comprehends at least one linguistic form in which the [LOCATION] concept is expressed. For example, he might comprehend phrases using in or on, but might fail to comprehend the particular linguistic form where. In contrast, the cognitive hypothesis predicts that the child does not understand the underlying concept [LOCATION] and, for that reason, does not comprehend any of the forms that express it,3 that is, neither where nor phrases using in or on. Thus, the pattern of the child’s responses to questions of different form constitutes the criterion for supporting a linguistic versus cognitive interpretation of inappropriate language.
To test the hypotheses represented in Figure 1, the present study focused on conversational interactions in which a child with a semantic-pragmatic disorder responded to adult questions about a story. The goal was to determine whether the child’s inappropriate responses could be accounted for by a linguistic explanation (poor comprehension of particular interrogative words).
Methods Subject
Background H.N. was 4;l (years;months) when he was referred to the clinical branch of the Child Language Center by his parents. They expressed concerns that he had difficulty
However, the ‘no-difference’ pattern would not provide conclusive evidence in favour of the cognitive hypothesis, because the absence of any difference in responses between forms would also be compatible with possible linguistic interpretations-for example, that both linguistic forms are understood equally well or equally poorly. Thus, because this study used only linguistic evidence, it is possible to rule out the cognitive hypothesis and support the linguistic hypothesis, but it is not possible to rule out the linguistic hypothesis and uniquely support the cognitive hypothesis. In future studies, both linguistic and non-linguistic data could be analysed to investigate the cognitive hypothesis more directly.
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Linguistic account of a semantic-pragmatic disorder 285
expressing ideas and processing spoken information, and reported that he sometimes used incorrect verb forms, pronouns, and word order (e.g. ‘I got fire for the wood’). H.N. lived at home with his parents and 7-year-old brother. His health had been good except for a severe lung infection at birth and a history of otitis media until age 2 years. Speech and language milestones were unremarkable except that H.N. began echoing what was said to him and using jargon between 18 and 24 months. His parents reported that these behaviours had decreased substantially, but some echoing and some derivatives of jargon (especially neologisms) continued to be used.
Hearing, non-verbal cognitive, and social skills At the time of referral, H.N. passed a hearing screening for pure tones of 500 Hz at 25 dB HL and tones of 1000, 2000, and 4000 Hz at 20 dB HL. Non-verbal cognitive skills were assessed by the Kaufman Assessment Battery for Children (Kaufman and Kaufman, 1983). The results showed that H.N. was in the 55th percentile for children of his age.
H.N.’s teachers reported that he participated well in pre-school activities, but often had poor attention in group settings or made comments at inappropriate times. These characteristics suggest that H.N. had some concomitant social, affective, or attentional deficits, although he was not regarded as autistic by his parents, his paediatrician, or the speech-language pathologist at the Child Language Center who supervised his clinical evaluation. H.N.’s constellation of behaviours (inappropriate language and communication problems without autism but occurring in conjunction with some social-affective signs) is frequently reported in children with a semantic- pragmatic disorder (Bishop and Rosenbloom, 1987) and is compatible with Bishop’s ( 1989) definition of a ‘specific semantic-pragmatic disorder’.
Language skills Standardized test results. Receptive and expressive skills for concepts, syntax, and morphology were assessed by the Northwestern Syntax Screening Test (Lee, 1971) and by the Test of Early Language Development-11 (Hresko, Reid and Hammill, 199 1 ). Expressive skills were additionally evaluated by the Structured Photographic Expressive Language Test-11 (Werner and Kresheck, 1983). H.N.’s ability to under- stand and express concepts (labels, categories, attributes, functions, and definitions) was evaluated by Assessing Semantic Skills through Everyday Themes (Barrett. Zachman and Huisingh, 1988). As summarized in Table 1, the receptive and express-
Table 1. H. N. ’s norm-referenced language test results (age 4 : 1 to 4 : 3 )
Test name Raw score Percentile Z-Score
NSST (Receptive) 27 50 0 NSST (Expressive) 5 10 -2.00 ASSET (Receptive) 16 1 - 2.47 ASSET (Expressive) 7 2 - 1.60
- 2.57 - SPELT-I1 23 TELD-2 45 73 0.60
NSST = Northwestern Syntax Screening Test (Lee, 1971); ASSET = Assessing Semantic Skills through Everyday Themes (Barrett, Zachman and Huisingh, 1988); SPELT-I1 = Structured Photographic Expressive Language Test-II (Werner and Kresheck, 1983); TELD-2 = Test of Ear1.v Language Development-ZZ (Hresko, Reid and Hammill, 1991 )
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ive test results were inconsistent. In general, standardized tests did not reveal the language skills that H.N. demonstrated in conversational speech.
Conversational speech. A language corpus was obtained at age 4;l in a question- and-answer activity about a story (described in Materials). An additional sample of 100 utterances was recorded while H.N. and his mother played with a set of toys and pretend picnic items, and H.N. responded to questions about the activities posed by his mother. These samples clearly indicated that H.N. had productive control of grammatical features such as inflections (including examples of overregula- rization, e.g. ‘You drawed an apple’), verbal auxiliaries, and determiners (see Table 2). The 150-utterance sample also contained three constructions involving sentential complements (e.g. ‘I watched Thomas get bumped’) and five utterances using coordinate sentence or coordinate noun phrase structures (e.g. ‘Where’s Cookie Monster, and Ernie and Bert?’).
Pragmatics. The language corpora also indicated that H.N. used language for a variety of communicative functions, including commenting or labelling (e.g. ‘It’s a hotdog’, ‘Well, it goes on the table’), for requesting (‘Where’s Cookie Monster and Ernie and Bert?’, ‘A trailer?’), for social interaction (‘Hi’, ‘Bye’, ‘Yeah’, ‘Okay’), and for affective expression (e.g. ‘Another big slide!’). Intonation patterns were used appropriately to express these speech acts. Language was typically used for comments in response to questions (responsive uses of speech), with few questions or comments adding new information (assertive uses). This tendency towards responsive and unassertive language may reflect the question-and-answer type of interaction that was the focus of this study.
Phonology. Articulation skills appeared to be excellent. Intelligibility was inform- ally assessed at 95% or more in spontaneous speech. Oral structures, as well as fluency, voice quality, and resonance seemed to be normal, but were not assessed formally.
Word usage. Given the overall sophistication of H.N.’s expressive language, two aspects of his conversational speech were striking. First, he used the subject pronouns
Table 2. H. N. ’s percentage of use of grammatical morphemes (n = frequency of obligatory contexts in a 150-utterance sample)
Morpheme Example n Percentage correct
a, the He gave me a cookie 45 96 - ing He’s going home 10 100 in, on It goes on the table 9 100 plural -s Just milk and bananas 6 100 possessive - s Where’s Big Bird’s nest? 2 100
past -ed He jumped off 4 I00 3rd singular -s He takes it 4 I5 3rd singular irregular ‘Be careful,’ says driver 2 100
copula contractible He’s very angry with that frog 14 100 copula uncontractible There he is 3 100
irregular past She fell in the water 9 87
auxiliary contractible They’re going to catch him 16 92
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Linguistic account of a semantic-pragmatic disorder 287
he and she interchangeably, an observation that was confirmed by parent report. For example, the utterances ‘He hurt his shoe’ and ‘She fell in the water’ referred to the same story character (a boy).
Second, he sometimes used unusual lexical choices such as ‘I’m making a motors’ (for I’m making a road). Criterion-referenced probes indicated that H.N. sometimes named objects by semantic association, for example, ‘a teeth’ for brush, ‘a cut’ for scissors, ‘teacher’ for child friend at school, ‘a cradle’ or ‘ball’ for rattle. Less frequently, an incorrect word choice seemed to reflect a phonetically based substitu- tion, such as ‘potato’ for tomato. In addition, neologisms were frequently used, for example, [tjakiz] for an unknown kind of food, [ m ~ k ] for rattle, [b~to] for taco. In most cases H.N. appeared to comprehend the words he did not name correctly; for example, brush, scissors, rattle, and tomato.
Summary. H.N.’s conversational speech indicated that he correctly used most classes of linguistic form that the standardized tests were designed to assess (noun and verb inflections, syntactic constructions, prosodic features, speech sounds and a variety of grammatical words such as verbal auxiliaries, prepositions and deter- miners). Nonetheless, the standardized test results were generally poor, perhaps because H.N. had difficulty interpreting some of the eliciting questions. In contrast to his generally appropriate use of grammatical form, H.N. seemed to have difficulty selecting and interpreting lexical items and pronouns.
Materials
Question-and-answer activities were designed around two stories illustrated by pic- tures. Story 1 was taken from a picture book without words about a boy, a dog and a frog. A text corresponding to the non-verbally depicted content was con- structed. Questions for story 1 were devised by H.N.’s mother, who had been instructed to ask questions that she might use in the home environment to discuss the story. Answers to 37 questions were analysed.
H.N.’s responses were categorized by the experimenter as appropriate or in- appropriate. Each eliciting question was categorized by its type (e.g. yeslno, Wh- question with where, what, who). Wh-questions were also categorized according to the relational concept (or semantic role) expressed by the Wh-word referent, using the following categories proposed by Chafe (1970) in his semantic analysis of interrogative constructions.
Relational concept Example [AGENT] Who got Fido? [ACTION] What is he doing? [PROCESS] What happened next? [PATIENT] What did Max see? [LOCATION] Where is the frog? [PREDICATE NOUN] Who is this little boy?
Story 2 was selected by H.N.’s parents. It was about Fievel the mouse, a character that was known to H.N. from other stories even though story 2 itself was new. The experimenter constructed a set of 14 comprehension questions using what and who
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interrogative pronouns. The questions were evenly divided between the two types of Wh-words and the relational concept varied within each Wh- t~pe .~
Procedures
The experimenter read the text of story 1 to H.N. while H.N. looked at the illustrations. H.N.’s mother listened to and observed the activities from an adjacent room. After the story was completed, she asked the comprehension questions. The experimenter read story 2 to H.N. with the support of pictures, pausing at relevant junctures in the story to ask the comprehension questions one at a time. All activities were audio- and video-taped.
To investigate the possibility that H.N.’s poor comprehension was related to the unfamiliar story content rather than the questions about it, the activities for story 2 were repeated, in a second session, 1 week later. In the week between the two sessions, after being asked not to practise comprehension questions, H.N.’s parents read story 2 to him several times, showing him the pictures, using gestures and expressive prosody as needed, and commenting on it. H.N.’s parents did not observe the question-and-answer activities for session 1, so that they were unaware of the questions that were used.
A chi-square analysis assessed the consistency of association between H.N .’s inappropriate versus appropriate responses and the Wh-forms expressed in the adult’s preceding question.
Results
The experimenter’s judgements of appropriate versus inappropriate responses agreed with those of a second judge in 60 of the 65 instances reported in this paper (92%). Some examples of H.N.’s inappropriate responses to questions about stories 1 and 2 are given next.
Question (possible appropriate responses) Who’s this little boy? (Max) Who made the shadow? (Fievel) Who was making the shadow? (Fievel ) What does Max see? (A frog) Who got Fido? (Max) Who is Tanya? (Fievel’s sister) Who set the mice free? { Fievel)
H. N. ’s responses He got a bucket for the frog. Big. Fievel was scared She said: there’s a frog. Fido. Well, he’s not a fraidy mouse. They open them up.
The results of the distributional analysis of questions to story 1 are presented in Table 3 , which shows that the appropriateness of H.N.’s responses differed according to the eliciting questions. Developmentally advanced questions using how or why (Table 3 , Group 2) were never responded to appropriately, but some developmentally easier items, such as where and yeslno questions, were always responded to correctly.
The set of questions was also controlled for the verbatim versus inferential relation existing between the target answer and the text, a variable that affects the difficulty of questions (Pearson and Johnson, 1978). Because preliminary analysis did not indicate any effects associated with this variable, it is not further discussed in this paper.
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Linguistic account of a semnntic-pragmatic disorder 289
Table 3. Ratio andproportion of appropriate responses to questions about story I by form and relational concept of the question word
Group Question Relational
word concept Example Ratio (and proportion)
la la la la la l a la la lb Ib 1 2 2 1 + 2
who who who what what what what subtotal yes/no where subtotal
AGENT PRED. NOUN PATIENT PRED. NOUN ACTION PROCESS PATIENT
LOCATION
how -
total why -
‘Who got Fido?’ 114 (0.25) ‘Who’s this little boy?’ 213 (0.67) ‘Who will he visit?’ 213 (0.67)
‘What’s Fido trying to do?’ 316 (0.50) ‘What happened to him?’ 8/8 (1.0) ‘What does Max see? 0/1 (0.50)
20129 (0.69)
‘What is his name? 4/4 (1.0)
‘Did you hear a story?’ 111 (1.0) ‘Where is the frog now?’ 3/3 (1.0)
24/33 (0.73) ‘How are they gonna catch that frog?’ 011 (0.0) ‘Why is he sad? 013 (0.0)
24/37 (0.65)
Note: Group 1 =early acquisitions ( la = who, whut, 1 b = where, yeslno); Group 2 = late acquisitions; - indicates that the relational concept is not defined in this study.
The difference in his response to why versus yes/no questions is illustrated in the following excerpt from a conversational interaction.
Mother’s question 1. Did you take my cookie? 2. Why did you take my cookie? 3. It’s by your hand? 4. I want it back.
H. N. ’s response Yeah. It’s over here by my hand. Yes. Okay. Here.
H.N. responded appropriately to the yes/no questions, including 3, which is signalled by intonation alone. He responded inappropriately only to the why question in 2.
The subsequent analysis focused on questions that 4-year-old children usually respond to appropriately, but that H.N. sometimes responded to inappropriately since tangential responses to questions that seem to be suitably matched to the child’s age and language development are the ones that most clearly elicit listener perceptions of bizarre or inappropriate usage (Bishop and Adams, 1989).
Accordingly, the rest of the analysis was restricted to what and ~ i h o questions (Table 3, Group la). Both of these are early acquisitions in children’s development of question structures (Brown, 1968). For example, structures using what in a variety of semantic roles and who in predicate noun constructions are cited as examples of early acquisitions at about age 2-3 years by Bellugi (1965) and Lee (1974). In Ervin-Tripp’s ( 1970) studies of the child’s comprehension of questions, children mastered what and where by 1;9 to 2;5 and most had mastered who at that age. Who functioning as the sentence subject was mastered by nearly 80% of children at 3;l (residual problems with this form disappeared by 3;9). However, who functioning as the object of a transitive verb continued to be interpreted as a subject by some children at 3;lO (for similar findings see Tyack and Ingram, 1977).
In the present study there were only two questions of the later-developing who- object type (however, H.N. responded appropriately to these two questions). Thus, the who and what questions that H.N. sometimes responded to inappropriately
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corresponded to question types that normally developing children have mastered before 3;9.
Table 3 shows that H.N. responded appropriately more often to what than M ~ Z O
questions (79% versus 50%). The results for story 2 are listed in Table 4. They show that the principal disparity between question types that was observed in story 1 (fewer appropriate responses to who questions than what questions) was also observed in both sessions of story 2.
Did H.N. have difficulty with the Wh-forms (who vs. what) or with the relational concepts extrinsically associated with them (e.g. [PATIENT], [AGENT], [PREDICATE NOUN])? To address this question the data across stories and sessions were combined in order to include as many instances as possible of different relational concepts and question forms. H.N.’s ratios and proportions of appropriate responses to both stories are shown in Table 5 (the data for story 2 reflect averages across sessions 1 and 2).
Generally, the data for [ACTION] and/or [PATIENT] concepts reflect a different pattern than [AGENT] and/or [PREDICATE NOUN] concepts. That is, the latter two group together for questions in which they are both represented (who questions), and the former two group together for questions in which they are both represented
Table 4. Ratio and proportion of appropriate responses to questions about story 2 by session and form and relational concept of the question words
Question word
who who
what what what
Subtotal
Subtotal Total
Relational concept
AGENT PRED. NOUN
PRED. NOUN ACTION PATIENT
Session
Example 1
‘Who set the mice free?’ 2/5 (0.40) ‘Who is Tanya?’ 0/2 (0.00)
2/7 (0.29) ‘What is his name?’ 3/3 (1.0) ‘What will Fievel do?’ 2/3 (0.67) ‘What did the cat see? l / l (1.0)
6/7 (0.86) 8/14 (0.57)
2 ~~
3/5 (0.60) 1/2 (0.50) 4/7 (0.57) 3/3 (1.0) 3/3 (1.0) l / l (1.0) 7/7 (1.0)
11/14 (0.79)
Table 5. Ratio and proportion of appropriate responses to questions by story and form and relational concept of the question word
Question Relational word concept
who AGENT who PRED. NOUN who PATIENT
what PRED. NOUN what ACTION what PROCESS what PATIENT
Subtotal
Subtotal Total
Example
‘Who got Fido?’ ‘Who’s this?’ ‘Who will he visit?’
‘What’s his name?’ ‘What will he do? ‘What happened? ‘What does Max see?’
Story
1 2 1 +2 ~~
1/4 (0.25) 5/10 (0.50) 6/14 (0.43) 2/3 (0.67) 1/4 (0.25) 3/7 (0.43) 2/3 (0.67) - 213 (0.67) 5/10 (0.50) 6/14 (0.43) 11/24 (0.46) 4/4 (1.0) 6/6 (1.0) 10/10 (1.0) 3/6 (0.50) 5/6 (0.83) 8/12 (0.75) 8/8 (1.0) - 8/8 (1.0) O/l (0.00) 2/2 (1.0) 2/3 (0.67)
15/19 (0.79) 13/14 (0.93) 28/33 (0.85) 20/29 (0.69) 19/28 (0.68) 39/57 (0.68)
Note: - indicates that this question type was not used.
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Table 6. Ratio and proportion of appropriate responses to questions about stories 1 and 2 by form and relational concept of the question word
~ ~ ~~
Question word Relational concept who what Total
[ + GOAL] [ - GOAL]
Total
2/3 (0.67) 18/23 (0.78) 20/26 (0.77) 9/21 (0.43) lO/lO (1.0) 19/31 (0.61)
11/24 (0.46) 28/33 (0.85) 39/57 (0.68)
Table 7. Chi-square tests of the relation between the appropriateness of H. N. ’s response and the forms, concepts, and syntax of the eliciting questions: Values of x2 andprobabilities (d.f. = 1)
Variable Value
forms: wholwhat concepts: [ + / - GOAL] syntax: +/ - Wh-movement
9.789 1.599 1.018
0.01 0.30 0.50
(what questions). This suggests that the main conceptual distinction in these question types is between (1) concepts conveyed by verbs (actions or processes) and their patients, and ( 2 ) agents and predicate nouns.
In addition, theoretical arguments also support a strategy of grouping concepts by putting verbs and patients together. For example, Chafe (1970) cited sentences such as ‘Harriet broke the dish. She did it accidentally’, and pointed out that the phrasal pro-form did it refers both to the verb (broke) and patient (dish). The pronominalization process, Chafe argued, treats the verb and patient configuration as a unit (but no analogous processes apply, say, to the verb and agent configuration as a similarly cohesive unit).
In light of the patterns in the data and the linguistic arguments discussed above, the relational concepts pertaining to verbs ([ACTION] and [PROCESS]) and [PATIENT] were combined to form a general class called [+GOAL] relations. The concepts pertaining to the other relations ([AGENT] and [PREDICATE NOUN]) were combined to form another class called [ - GOAL] relations. The data aggregated across the story sets and grouped under the binary relational concepts and question words are shown in Table 6 .
Chi-square analysis revealed a significant effect only for the Wh-words, but not for the underlying relational concepts5 (see Table 7). The Wh-constructions also differed in syntactic characteristics. Some could be interpreted as surface sentences reflecting the grammatical operations of Wh-fronting and auxiliary movement (e.g. ‘Who will they visit?’). Other constructions do not reflect these movement operations (e.g. ‘Who got Fido?’). There was no evidence from chi-square analysis (Table 7)
When the data were edited to include only questions with the specific relational concepts that were shared by both Wh-forms ([PATIENT] and [PREDICATE NOUN]), the pattern of significant findings was the same as that reported for the entire data set grouped under the binary relational concept categories [ + / - GOAL]. That is, the frequency of appropriate responses was independent of the relational concepts (x2=0.221, d.f.=l, p<0.7), but not of the linguistic forms (x2=5.247, d.f. =1, p<O.O5).
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that the presence or absence of these syntactic characteristics was related to the frequency of H.N.’s inappropriate responses.
Apart from extrinsic differences in associated relational concepts, who and what differ intrinsically by a single object concept, that is [ + / - ANIMATE].^ The same distinction is marked by personal pronouns he or she versus it (Chafe, 1970) and, in some cases, by proper nouns. A review of H.N.’s transcripts indicated that he used these forms appropriately with respect to the [ + / - ANIMATE] concept. Examples include: ‘Bert’s in his house’, ‘It’s a bucket’, ‘It goes on the table’, ‘He got him’, ‘He found it’, ‘He put it over his head’, and ‘She was very sad’. In these examples, proper nouns and pronouns he or she always had animate referents (in actuality or in pretend play), whereas it always had an inanimate antecedent. Thus, there is no evidence from H.N.’s spontaneous speech to indicate that his inappropriate responses to who versus what questions can be attributed to an inability to understand the concept of animacy.
Discussion
The clinical evaluations of non-verbal skills indicated that H.N. had normal hearing sensitivity and normal non-verbal cognitive scores. However, he was more than two standard deviations below the mean on a number of language development measures (e.g. SPELT-11, ASSET); thus, he meets the broad criteria for a specific language impairment.
With few exceptions the observations of conversational speech show that he was not impaired in phonology or language form. Sentences were in general highly intelligible and well formed with respect to the use of word-order, inflectional morphology, and most grammatical words such as determiners, verbal auxiliaries and prepositions. Although minor problems with language form were observed, the most striking characteristic of his conversational speech was ‘inappropriateness’. These language characteristics indicate that H.N.’s language profile corresponds to a semantic-pragmatic type of SLI rather than the type of SLI with morphosyntactic deficits, for example, the phonological-syntactic syndrome (Bishop and Rosenbloom, 1987; Rapin and Allen, 1983).
The study of H.N.’s responses to questions was based on the assumption that his inappropriate responses reflected poor comprehension of some of the questions addressed to him. In a manner consistent with this assumption, the findings indicated that inappropriate responses were linked to the type of question he was responding to. An especially high rate of inappropriacy was observed when H.N. responded to questions introduced by who in contrast to what. In addition, there were no apparent effects of practice on H.N.’s pattern of responses to these question types. The asymmetry between types of Wh-questions was not affected by verbal and non- verbal training designed to make the story’s concepts more familiar and, hence, more understandable.
H.N.’s high frequency of inappropriate responses to who questions relative to what questions cannot be reasonably attributed to a poor understanding of the
In Chafe’s (1970) analysis, who is intrinsically associated with the concept [HUMAN]. H.N.’s mother used who to refer to animal characters in stories, for example, pets (Mom: ‘Who does he have with him? H.N.: ‘Fido’). Chafe discusses similar examples using pronouns like he. In this study the category [ANIMATE] is used as a rough approximation of the relevant concept.
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extrinsic relational concepts conveyed by the interrogative pronoun who, because an overlapping set of concepts was also conveyed by the pronoun what. Similarly, the asymmetry cannot be attributed to a poor understanding of the concept of [ANIMATE] because H.N. used other forms appropriately that express this concept. Finally, features related to syntactic complexity (e.g. application of Wh-fronting) also do not account for the asymmetry. Instead, the results suggest that although H.N. did not properly interpret particular Wh-forms, he did understand the underlying con- cepts when they were expressed in other linguistic forms. This pattern is consistent with the linguistic hypothesis but not with the cognitive hypothesis.
H.N. did not spontaneously ask Wh-questions (recall that his speech in the context of this study was characterized as responsive and unassertive), so there is little or no evidence from production to corroborate the receptive findings. However, the analysis of his conversational speech indicated expressive and receptive difficulty with pronoun forms other than Wh-words (e.g. confusion of he and she). Thus, the problems with interrogative pronouns may be part of a more extensive receptive and expressive problem with pronoun forms generally.
The findings of this case study are consistent with clinical reports that children with a semantic-pragmatic disorder usually have difficulty with pronouns as well as with questions (Bishop and Rosenbloom, 1987; Rapin and Allen, 1983). The results summarized here suggest that the previously reported problems with questions and pronouns may stem from a single source, because the source of the difficulty with question constructions may be the interrogative pronouns that Wh-questions use.
Evidence from conversational speech also showed that H.N. had difficulty expressing words other than pronouns. In particular he demonstrated word-choice errors, a type of error frequently mentioned in clinical reports of this population (e.g. Bishop and Adams, 1989). These errors included neologisms, but most could be interpreted as semantically based substitutions, for example, ‘a cut’ for scissors, ‘a king’ for crown, ‘a soapwash’ for towel. However, when H.N. was verbally asked to demonstrate in pantomime how a towel, for example, was used, he could do so appropriately. The semantic associations that were evident in these substitutions in addition to the appropriate non-verbal actions indicated that he understood the object concepts. These findings suggest that the problems with lexical items, like those with pronouns, reflect difficulty selecting or interpreting appropriate forms. This isolated impairment of form (with concepts intact) is consistent with the general definition of linguistic deficits that was proposed in the introduction.
Summarizing, the findings of this study support the linguistic explanation that Bishop and Adams (1989) proposed to account for inappropriate language stemming from apparent expressive deficits. The present results extend the scope of the linguistic explanation to include additional instances of inappropriate language, such as tan- gential or irrelevant responses to questions, which appear to reflect receptive deficits.
This study reports observations for only one child, and thus the findings must be interpreted with caution. In spite of this limitation the results suggest that the linguistic hypothesis warrants further investigation in studies of children with a semantic-pragmatic disorder. Among immediate practical implications, the findings also suggest that clinical evaluations of such children might usefully incorporate techniques to determine whether a child’s apparent comprehension deficits are uni- forrnly represented across different form contexts or whether they are associated uniquely with specific linguistic forms.
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Theoretical implications
To the extent that H.N.’s inappropriate language behaviours can be interpreted as linguistic deficits, it is possible that the semantic-pragmatic type of SLI that he demonstrates may be analogous to the type of SLI characterized by impairments of morphosyntax, given that the latter deficits are also defined in linguistic terms. In fact, despite the different language profiles, the two types of SLI may be closely related on the explanatory level targeted by theory.
Morphosyntactic disorders
Children with primary deficits in grammatical morphology have particular difficulty with inflectional morphemes and auxiliary verbs (Leonard, Bortolini, Caselli, McGregor and Sabbadini, 1992). These are formal elements that agree with syntactic features in sentences and are thus predictable. Indeed, Brown (1973) refers to ‘obligatory contexts’ as a way of defining the rule-governed predictability of these functional morphemes. In English the morphological problems associated with this type of SLI are mostly omissions, for example, the omission of -ed in an obligatory context such a ‘Yesterday, we play inside’.
To account for grammatical morpheme omissions in SLI, researchers have recently proposed a phonological storage/access theory (Connell and Stone, 1992; Swisher and Snow, 1994). The main tenet of this theory (and of related memory- based approaches, e.g. Gathercole and Baddeley, 1990) is that children with SLI are impaired in their ability to store and access phonological forms in verbal memory.
Using a computational approach, for example, Hoeffner and McClelland (1993) showed that phonological impairments could lead to morpheme omissions of the type that children with morphosyntactic deficits demonstrate. In their interactive model, phonological impairments adversely affected inflected forms more than unin- flected forms. In the resulting utterances predicted by the computational algorithms, inflections were frequently omitted, although the omissions could be viewed as substitutions of the phonologically stronger, uninflected member of inflectional paradigms, for example, play, for the weaker inflected form, played.
Computational models such as the one used by Hoeffner and McClelland are designed to simulate processing at different levels of language structure. An import- ant implication is that the phonological component discussed above in relation to morphosyntactic phenomena also interfaces with the lexical level of linguistic processing, as discussed next.
Semantic-pragmatic disorders
Like other children with a semantic-pragmatic disorder, H.N. does not have marked difficulty with inflectional morphology. Instead, he has difficulty with lexical items and other referential words that are not predictable by the syntax. The distinction between lexical and syntactic processes can be illustrated by one of H.N.’s utterances that was cited earlier: ‘I’m making a motors.’ H.N.’s use of ‘a motors’ seems to reflect a semantically based lexical substitution (‘motors’ for road), and is thus similar to other errors observed in his speech. However, the inappropriate article usage is not consistent with the correct grammatical patterns he normally used, for example, ‘a potato’, ‘a firetruck’, ‘bananas and milk’, ‘The truck’s going to get some
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Linguistic account of a semantic-pragmatic disorder 29 5
Figure 2. Schematic of a spreading activation model of word retrieval (dotted lines between ‘words’ and yo rm’ indicate phonological activations which, if weakened, could lead to semantically related naming errors such as cradle or ball for rattle).
groceries’. If, instead, ‘motors’ is viewed as a lexical-selection error, the apparent inconsistency with regard to article usage is resolved, since the indefinite article a would be appropriate in the target utterance ‘I’m making a road’. This interpretation of such examples supports the conclusion that H.N.’s errors reflect inaccurate lexical- retrieval processes rather than difficulty with grammatical morphemes.
Recent investigations of adult aphasia and dyslexia have shown that phonological impairments could lead to semantic lexical substitutions of the kind that H.N. demonstrates (Caramazza and Hillis, 1990; Martin and Saffran, 1992). An example shown in Figure 2 features Martin and Saffran’s adaptation of the ‘spreading activa- tion’ model proposed by Dell ( 1986). The model shown in Figure 2 is closely related to the computational approach that Hoeffner and McClelland used to account for grammatical morpheme omissions in SLI. Here it simulates impaired lexical processes instead.
Figure 2 depicts feed-forward and feed-back activations between phonological and conceptual features in the context of a naming task.’ The spreading network ‘activates’ not only the target word (rattle, i.e. a baby’s rattle) but also, to a lesser extent, phonologically and/or semantically related words (e.g. cradle, puddle). As depicted schematically in Figure 2, a correct word choice occurs when the conceptual and phonological features jointly converge on the target item, thereby providing by consensus a greater activation level for that item than for any of the competing candidates.
However, if the phonological pathways are weakened (dotted lines in Figure 2), candidate items activated by the spared semantic pathways (e.g. cradle, bull) become more eligible for selection than they would be if the phonological pathways were unimpaired. The resulting asymmetry in phonological-conceptual activation levels could result in the selection of a lexical item that is incorrect but related to the
7Martin and Saffran (1992) have adapted the same computational model to account for receptive processes as well.
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target in meaning, for example, cradle or ball, both of which were chosen by H.N. in different versions of an informal naming task. A similar semantically based mechanism could explain the confusions of closely related pronouns such as he and she. This phonologically based explanation of lexical and pronoun errors (occurring in semantic-pragmatic disorders) exactly parallels the explanation of grammatical morpheme omissions (occurring in disorders marked by morphosyntactic deficits) that was described in the preceding paragraphs.
In conclusion, the linguistic deficits of the morphosyntactic and semantic-prag- matic types of SLI can be predicted by a single phonological storage/access theory. Thus, the primary difference between the two syndromes may be that different linguistic form classes are impaired. Children with a morphosyntactic type of SLI (as the name implies) demonstrate deficits in regard to morphemes that have a syntactic function, while children with the semantic-pragmatic type of SLI (in a manner not directly implied by the name) demonstrate deficits in regard to lexical items and pronouns-that is, form classes that have a referring function.
The possibility that a single type of disturbance could affect different form classes is not unknown in the study of language impairment. In acquired language disorders, non-fluent aphasia disproportionately affects grammatical morphology and syntax, whereas the fluent aphasias primarily affect lexical elements (Buckingham, 1979). These distinct types of aphasia are both caused by brain damage, but they are associated with different cortical strata (Benson, 1967). In light of growing evidence that developmental disorders may also have a neurogenic explanation (Rapin and Allen, 1988), syndromes differentially affecting morphosyntactic and lexical form- classes may also implicate different sites of involvement (Snow and Swisher, in press).
Summary
The results suggest that H.N.’s inappropriate responses to questions may be accounted for by a linguistic explanation-namely, that he has difficulty with the storage/access of linguistic forms. Thus, some semantic-pragmatic behaviours that appear to implicate disturbed concepts may actually have a linguistic-form basis.
Inasmuch as morphological deficits are interpreted as a reflection of impaired linguistic form, the present results suggest that the semantic-pragmatic and morpho- syntactic types of SLI may be more closely related than the different names and ostensible behaviours imply. Indeed, I propose that the two types of SLI are unified under the theoretical umbrella of a single phonological storage/access account. The essential difference between the syndromes, therefore, does not hinge on broad skill categories such as semantics or pragmatics, but rather on the distinction between the class of referential words that is primarily impaired in the semantic-pragmatic type of SLI and the class of function words and inflections that is primarily impaired in the morphosyntactic type.
Acknowledgements
This research was funded in part by US Department of Education Grants H029D90108 and H023C40118-95, and by a McDonnell-Pew grant from the Cognitive Neurosciences programme at the University of Arizona. The author thanks Rebecca Vance, who played a key role in the clinical evaluation supporting this case study. Special thanks also to Linda Swisher for insightful comments, and Mary
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Linguistic account of a semantic-pragmatic disorder 297
McNamara for her contribution to the reliability portion of the study. Also gratefully acknowledged is the Tucson Scottish Rite Charitable Foundation whose support of the clinical programme associated with the Child Language Center made this study possible.
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