87
THE EFFECT OF INTONATIONAL EMPHASIS ON SENTENCE COMPREHENSION IN SEVERELY SUBNORMAL AND NORMAL CHILDREN*
KEVIN WHELDALL**
University of Birmingham and WILLIAM SWANN Schools Council Project, Cheshire Education Committee
The effect of intonational emphasis on the sentence comprehension of severely subnormal and normal pre-school children was investigated by stressing the critical elements of sentences of varying syntactic structure. The results concurred with previous work insofar as intonational emphasis did not facilitate comprehension. There was, however, some evidence to show that intonational emphasis may have a effect on the subnormal child’s comprehension of negative structures.
detrimental
-,
~
INTRODUCTION
’
The processes and mechanisms by which we try to understand what another person is saying involve a guessing strategy in which we combine what cues we can get from the speaker with our pre-existing expectations of what we think he is going to say. There is much current interest in the non-verbal factors affecting communication including facial expression, gesture, tone of voice, etc. (Argyle 1969, 1972a). The understanding of what people say does not necessarily tell us what they mean, unless we also take their non-verbal contribution into account. Thus, teaching a subnormal child merely to comprehend verbal utterances may not be enough, if general comprehension is being hindered by his inability to make use of non-verbal information.
* The research reported in this paper was carried out at the Hester Adrian Research Centre, University ofManchester and was financed by S.S.R.C. grant 840/1 awarded to Professor P. Mittler. The authors would like to thank their supervisor, Professor Mittler, for his help in the initial formulation ofthe experiments and his comments on the various drafts of this paper. Thanks also to the Headmistress and staff of the following schools : Wigton Special School, Cumberland; Hensingham Special School, Cumberland; The Birches Special School, Manchester; Shakespeare Street Nursery School, Manchester; Collyhurst Nursery School, Manchester; Harper Mount Nursery School, Manchester.
**Formerly
at the Hester Adrian Research
Centre, University ofManchester.
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
88
However, in order to obtain ’uncontaminated ’ data on the purely linguistic processing of the child, it is necessary to assess this ability divorced as far as possible from
ability
.
_
’
.
the wider communication context within which language is normally only one element. To exclude non-linguistic cues is to a certain extent artificial, since the normal child is able to use such cues in everyday comprehension situations. However, it remains to be demonstrated just how much extra information is received and made use of by the subnormal child who is exposed to the additional non-verbal cues of normal conversation. A measure of sentence comprehension is being developed at the Hester Adrian Research Centre. The test aims to provide systematic data on the child’s ability to comprehend sentences of gradually increasing length and structure (Hobsbauin and Mittler, 1971; Mittler and Wheldall, 1971). In the Sentence Comprehension Test (S.C.T.) the child is presented with four examples of 15 types of sentences of varying complexity and grammatical structure. His task is to identify which of three or four simultaneously presented pictures corresponds to the sentence spoken by the tester. The pictorial referents are systematically varied to illustrate alternative grammatical interpretations. Thus, following the target sentence &dquo; The boy is reading the paper &dquo;, the child has to point to the picture illustrating this sentence from four alternatives : : .. , The boy is reading the paper (target sentence). _.-.. _ .. , _ The girl is reading the paper (subject varied). The boy is tearing the paper (verb varied). The boy is reading the book (object varied). The 15 sentence types also include comparatives and superlatives, past and future tenses, passives, negatives, plurals, prepositions and embedded clauses. It is normal procedure to present the sentences in a relatively neutral, uninflected voice. Sufficient progress has now been made on the development of the Sentence Comprehension Test to allow a shift of emphasis which will include investigations of the effects of various non-verbal cues on the comprehension context. This follows Herriot’s suggestion that comprehension should be considered as &dquo; multiply cued behaviour &dquo; which involves a range of non-verbal as well as verbal cues, (Herriot, 1970; Herriot and Lunzer, 1971). The non-verbal factors which had previously been controlled may now be systematically re-introduced into the comprehension situation in order to In some respects the test functions as a dependent assess their respective importance. variable in order to provide data on the effects of these non-verbal factors on -
&dquo;
-
..
~,
,- , ,
.
&dquo;
’
’
,
’
’
’
.
’
.
comprehension. One obvious non-verbal variable, important for both its theoretical and practical implications, is the effect of intonation on sentence comprehension ability. Teachers both of young normal and subnormal children tend to adopt an exaggerated intonational style with the apparent aim of facilitating comprehension, but the effectiveness of this technique has yet to be demonstrated. A common categorization of non-verbal aspects of speech distinguishes prosodic sounds and paralinguistic sounds (Crystal, 1969). The latter includes &dquo; emotions
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
.
89 tone of voice, group membership expressed by accent, personality expressed by voice quality, speech errors, etc..... Prosodic signals are pitch pattern, stress pattern and juncture (pauses and timing) which affect the meaning of sentences &dquo;, (Argyle, 1972b, p.251). Fry (1958) using synthesized speech has shown that fundamental pitch and duration are important constituents of stress
expressed by
characteristics
in addition to the more obvious element of loudness. McLean and Tiffany (1973), reviewing previous research, have referred to the interaction of these three factors as a &dquo; complex trading relationship .... wherein the predominant feature varies from situation to situation &dquo; according to phonetic quality and context. They go on to suggest that there may be other relevant speech variables exerting consistent influences on the trading relationship such as syllable position, speech loudness and rate. Chomsky (1971) has suggested that stress may remove ambiguity from a sentence. For example in the sentence &dquo; John hit Bill and then George hit him &dquo; identification of the pronoun depends on the presence of stress on ’ him ’. Maratsos (1973) investigated this experimentally using children aged 3, 4 and 5 years old whom he divided up into groups on the basis of their proficiency in imitating sentences. The children were required to act out with play materials sentences of the type &dquo; Susie jumped over the old woman and then Harry jumped over her &dquo;. The presence or absence of stress on the pronoun was critical to the reference of the pronoun. &dquo; Performance on unstressed pronouns was uniformly high in all three groups. Stressed pronouns were acted out like unstressed pronouns by the least advanced group, and improvement was radical from the lowest to the highest groups &dquo;. Another function of stress, according to Martin and Roberts (1966) working with Yngve’s (1960) model, may be to signal to the listener the number of words likely to follow. Bolinger (1964) has referred to the use of stress or accent to &dquo; signal the importance of a word by accenting giving pitch prominence to one of its -
-
syllables &dquo;. Brown
(1965) has suggested that the &dquo; telegraphic speech &dquo; of children at the of their speech development may consist of those words in the sentence which are stressed (i.e. contentives rather than functors) and that &dquo; differential stress may be the cause of the child’s differential retention &dquo;. Arguing from this position, Frith (1969) and Hermelin and O’Connor (1970), using matched normal and autistic children, investigated the effects of emphasizing key words on the immediate recall of wcrd strings or ’ messages ’. Half of the messages were presented with a stress on connecting words (unnatural stress) while the rest of the material was presented with stress on the keywords (natural stress). Both normal and autistic children recalled keywords significantly better when stressed than when not stressed, but stress affected the recall of connecting words to a significantly lower degree. The effect of stress was found to be greater for children who were less mature mentally, as measured by digit span, irrespective of whether they were normal or autistic. Weener (1971) working on recall with young normal children also found that adding beginning
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
90 intonation to the verbally presented stimuli produced slight facilitation with anomalous strings and marked facilitation with meaningful strings. Shepard and Ascher (1973) following a replication of Weener’s findings concluded that &dquo; when material is presented orally to young children sentence cadence should be emphasized &dquo;. Amidon and Carey (1972) included intonational emphasis as a variable in a study of the comprehension of &dquo; before &dquo; and &dquo; after &dquo; in normal children aged 5-6 years. Intonational emphasis on these words had no effect, either positive or negative, on their comprehension of commands such as &dquo; Before you move a red plane, move a blue plane &dquo;. An unpublished experiment by Herriot (personal communication) examined the effect of stress or intonational emphasis in a comprehension context with young subnormal children. In this study two wooden &dquo; Wally Woodpeckers &dquo; were used who could be made to move in a pecking motion from the top to the bottom of a metal rod. Following Berko (1958), he termed this motion &dquo; glinging &dquo;. The children were, for example, shown one Wally in the process of glinging down the pole and another Wally poised at the top of his pole about to gling. The children were asked &dquo; which one is going to gling? &dquo;. There was no significant difference in correct responses between the group who were asked the question in a relatively neutral voice and another &dquo; group who were given the question with a loud, heavy stress on going to &dquo;. The effects of intonational emphasis, as reported above, appear to be somewhat inconsistent. If, as Frith’s work suggests, intonational emphasis facilitates recall and can lead to differential retention, as postulated by Brown, one would expect some effect on comprehension, if only an indirect one; but the few studies which have examined the effect of stress on comprehension have had negative results. In view of the practical relevance in terms of current classroom practice, the present experiments were designed to investigate the effects of intonational emphasis on the sentence comprehension ability of severely subnormal and normal children, using a wider range of sentence structures selected from S.C.T. The two reported studies on comprehension only examined one type of syntactic structure each (future tense and temporal sentence
prepositions). Intonational emphasis in the present research consisted of a loud, emphatic stress on the &dquo; critical element &dquo; of the various sentence structures. &dquo; Critical e~ement &dquo; was operationally defined as that element in the sentence structure which, on the basis of an empirically determined error analysis, most consistently leads to miscomprehension of that structure. For example in sentences of the type, .. The dogs are running errors tend to fall on the singular referent (i.e. pointing to one dog running) and not on the verb (i.e. pointing to sleeping rather than running) or on the subject (i.e. pointing to cows instead of dogs). If, in the example above, errors had fallen mainly on the subject (dogs) then this would have been operationally defined as the critical element. It was hypothesized that intonational emphasis on the critical elements would lead to improved comprehension of the structures examined.
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
91 lw
EXPERIMENT I
METHOD
_
Sub jects
°‘
‘
-
The subjects consisted of 26 severely subnormal children from two special schools in Cumberland who had been tested on the Sentence Comprehension Test (S.C.T.) and the English Picture Vocabulary Tests (E.P.V.T.) (Brimer and Dunn, 1962) one year prior to the present study. Their vocabulary ages (V.A.) as measured by E.P.V.T. were within the pre-school range (3 : 0 - 4 : 11 ). The chronological age range of the sample was 5 : 10 to 14: 9 with a mean of 9: 11. =
...
&dquo;
Materials
’.
The test consisted of a booklet of black and white picture arrays. For the purpose of the present study five sub-tests, each containing four sentences, were selected to form an abbreviated version of the test. The five sub-tests were not intended to be representative of the test as a whole but were selected for their suitability as a dependent variable. An error analysis of the subjects’ scores on their initial testing agreed with previous analyses in determining the sub-tests for which there were clear These error patterns, i.e. where errors tended to cluster on one picture referent. sub-tests were: Plural e.g. The girls are skipping. Future e.g. The dog is going to jump. Passive e.g. The car is being pushed by the bus. Negative e.g. The boy is not crying. Transitive Negative e.g. The boy is not opening the gate. The italicized words are the critical elements as previously defined. The order of difficulty of the 15 sub-tests of S.C.T. for S.S.N. children shows that the five selected sub-tests were among the more difficult, (Mittler and Wheldall, 1971). An analysis of existing data on S.C.T. showed that scores on the five sub-tests were a reasonably good predictor of scores on the same five sub-tests given two years later (r = 0.63, p
THE EFFECT OF INTONATIONAL EMPHASIS ON SENTENCE COMPREHENSION IN SEVERELY SUBNORMAL AND NORMAL CHILDREN*
KEVIN WHELDALL**
University of Birmingham and WILLIAM SWANN Schools Council Project, Cheshire Education Committee
The effect of intonational emphasis on the sentence comprehension of severely subnormal and normal pre-school children was investigated by stressing the critical elements of sentences of varying syntactic structure. The results concurred with previous work insofar as intonational emphasis did not facilitate comprehension. There was, however, some evidence to show that intonational emphasis may have a effect on the subnormal child’s comprehension of negative structures.
detrimental
-,
~
INTRODUCTION
’
The processes and mechanisms by which we try to understand what another person is saying involve a guessing strategy in which we combine what cues we can get from the speaker with our pre-existing expectations of what we think he is going to say. There is much current interest in the non-verbal factors affecting communication including facial expression, gesture, tone of voice, etc. (Argyle 1969, 1972a). The understanding of what people say does not necessarily tell us what they mean, unless we also take their non-verbal contribution into account. Thus, teaching a subnormal child merely to comprehend verbal utterances may not be enough, if general comprehension is being hindered by his inability to make use of non-verbal information.
* The research reported in this paper was carried out at the Hester Adrian Research Centre, University ofManchester and was financed by S.S.R.C. grant 840/1 awarded to Professor P. Mittler. The authors would like to thank their supervisor, Professor Mittler, for his help in the initial formulation ofthe experiments and his comments on the various drafts of this paper. Thanks also to the Headmistress and staff of the following schools : Wigton Special School, Cumberland; Hensingham Special School, Cumberland; The Birches Special School, Manchester; Shakespeare Street Nursery School, Manchester; Collyhurst Nursery School, Manchester; Harper Mount Nursery School, Manchester.
**Formerly
at the Hester Adrian Research
Centre, University ofManchester.
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
88
However, in order to obtain ’uncontaminated ’ data on the purely linguistic processing of the child, it is necessary to assess this ability divorced as far as possible from
ability
.
_
’
.
the wider communication context within which language is normally only one element. To exclude non-linguistic cues is to a certain extent artificial, since the normal child is able to use such cues in everyday comprehension situations. However, it remains to be demonstrated just how much extra information is received and made use of by the subnormal child who is exposed to the additional non-verbal cues of normal conversation. A measure of sentence comprehension is being developed at the Hester Adrian Research Centre. The test aims to provide systematic data on the child’s ability to comprehend sentences of gradually increasing length and structure (Hobsbauin and Mittler, 1971; Mittler and Wheldall, 1971). In the Sentence Comprehension Test (S.C.T.) the child is presented with four examples of 15 types of sentences of varying complexity and grammatical structure. His task is to identify which of three or four simultaneously presented pictures corresponds to the sentence spoken by the tester. The pictorial referents are systematically varied to illustrate alternative grammatical interpretations. Thus, following the target sentence &dquo; The boy is reading the paper &dquo;, the child has to point to the picture illustrating this sentence from four alternatives : : .. , The boy is reading the paper (target sentence). _.-.. _ .. , _ The girl is reading the paper (subject varied). The boy is tearing the paper (verb varied). The boy is reading the book (object varied). The 15 sentence types also include comparatives and superlatives, past and future tenses, passives, negatives, plurals, prepositions and embedded clauses. It is normal procedure to present the sentences in a relatively neutral, uninflected voice. Sufficient progress has now been made on the development of the Sentence Comprehension Test to allow a shift of emphasis which will include investigations of the effects of various non-verbal cues on the comprehension context. This follows Herriot’s suggestion that comprehension should be considered as &dquo; multiply cued behaviour &dquo; which involves a range of non-verbal as well as verbal cues, (Herriot, 1970; Herriot and Lunzer, 1971). The non-verbal factors which had previously been controlled may now be systematically re-introduced into the comprehension situation in order to In some respects the test functions as a dependent assess their respective importance. variable in order to provide data on the effects of these non-verbal factors on -
&dquo;
-
..
~,
,- , ,
.
&dquo;
’
’
,
’
’
’
.
’
.
comprehension. One obvious non-verbal variable, important for both its theoretical and practical implications, is the effect of intonation on sentence comprehension ability. Teachers both of young normal and subnormal children tend to adopt an exaggerated intonational style with the apparent aim of facilitating comprehension, but the effectiveness of this technique has yet to be demonstrated. A common categorization of non-verbal aspects of speech distinguishes prosodic sounds and paralinguistic sounds (Crystal, 1969). The latter includes &dquo; emotions
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
.
89 tone of voice, group membership expressed by accent, personality expressed by voice quality, speech errors, etc..... Prosodic signals are pitch pattern, stress pattern and juncture (pauses and timing) which affect the meaning of sentences &dquo;, (Argyle, 1972b, p.251). Fry (1958) using synthesized speech has shown that fundamental pitch and duration are important constituents of stress
expressed by
characteristics
in addition to the more obvious element of loudness. McLean and Tiffany (1973), reviewing previous research, have referred to the interaction of these three factors as a &dquo; complex trading relationship .... wherein the predominant feature varies from situation to situation &dquo; according to phonetic quality and context. They go on to suggest that there may be other relevant speech variables exerting consistent influences on the trading relationship such as syllable position, speech loudness and rate. Chomsky (1971) has suggested that stress may remove ambiguity from a sentence. For example in the sentence &dquo; John hit Bill and then George hit him &dquo; identification of the pronoun depends on the presence of stress on ’ him ’. Maratsos (1973) investigated this experimentally using children aged 3, 4 and 5 years old whom he divided up into groups on the basis of their proficiency in imitating sentences. The children were required to act out with play materials sentences of the type &dquo; Susie jumped over the old woman and then Harry jumped over her &dquo;. The presence or absence of stress on the pronoun was critical to the reference of the pronoun. &dquo; Performance on unstressed pronouns was uniformly high in all three groups. Stressed pronouns were acted out like unstressed pronouns by the least advanced group, and improvement was radical from the lowest to the highest groups &dquo;. Another function of stress, according to Martin and Roberts (1966) working with Yngve’s (1960) model, may be to signal to the listener the number of words likely to follow. Bolinger (1964) has referred to the use of stress or accent to &dquo; signal the importance of a word by accenting giving pitch prominence to one of its -
-
syllables &dquo;. Brown
(1965) has suggested that the &dquo; telegraphic speech &dquo; of children at the of their speech development may consist of those words in the sentence which are stressed (i.e. contentives rather than functors) and that &dquo; differential stress may be the cause of the child’s differential retention &dquo;. Arguing from this position, Frith (1969) and Hermelin and O’Connor (1970), using matched normal and autistic children, investigated the effects of emphasizing key words on the immediate recall of wcrd strings or ’ messages ’. Half of the messages were presented with a stress on connecting words (unnatural stress) while the rest of the material was presented with stress on the keywords (natural stress). Both normal and autistic children recalled keywords significantly better when stressed than when not stressed, but stress affected the recall of connecting words to a significantly lower degree. The effect of stress was found to be greater for children who were less mature mentally, as measured by digit span, irrespective of whether they were normal or autistic. Weener (1971) working on recall with young normal children also found that adding beginning
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
90 intonation to the verbally presented stimuli produced slight facilitation with anomalous strings and marked facilitation with meaningful strings. Shepard and Ascher (1973) following a replication of Weener’s findings concluded that &dquo; when material is presented orally to young children sentence cadence should be emphasized &dquo;. Amidon and Carey (1972) included intonational emphasis as a variable in a study of the comprehension of &dquo; before &dquo; and &dquo; after &dquo; in normal children aged 5-6 years. Intonational emphasis on these words had no effect, either positive or negative, on their comprehension of commands such as &dquo; Before you move a red plane, move a blue plane &dquo;. An unpublished experiment by Herriot (personal communication) examined the effect of stress or intonational emphasis in a comprehension context with young subnormal children. In this study two wooden &dquo; Wally Woodpeckers &dquo; were used who could be made to move in a pecking motion from the top to the bottom of a metal rod. Following Berko (1958), he termed this motion &dquo; glinging &dquo;. The children were, for example, shown one Wally in the process of glinging down the pole and another Wally poised at the top of his pole about to gling. The children were asked &dquo; which one is going to gling? &dquo;. There was no significant difference in correct responses between the group who were asked the question in a relatively neutral voice and another &dquo; group who were given the question with a loud, heavy stress on going to &dquo;. The effects of intonational emphasis, as reported above, appear to be somewhat inconsistent. If, as Frith’s work suggests, intonational emphasis facilitates recall and can lead to differential retention, as postulated by Brown, one would expect some effect on comprehension, if only an indirect one; but the few studies which have examined the effect of stress on comprehension have had negative results. In view of the practical relevance in terms of current classroom practice, the present experiments were designed to investigate the effects of intonational emphasis on the sentence comprehension ability of severely subnormal and normal children, using a wider range of sentence structures selected from S.C.T. The two reported studies on comprehension only examined one type of syntactic structure each (future tense and temporal sentence
prepositions). Intonational emphasis in the present research consisted of a loud, emphatic stress on the &dquo; critical element &dquo; of the various sentence structures. &dquo; Critical e~ement &dquo; was operationally defined as that element in the sentence structure which, on the basis of an empirically determined error analysis, most consistently leads to miscomprehension of that structure. For example in sentences of the type, .. The dogs are running errors tend to fall on the singular referent (i.e. pointing to one dog running) and not on the verb (i.e. pointing to sleeping rather than running) or on the subject (i.e. pointing to cows instead of dogs). If, in the example above, errors had fallen mainly on the subject (dogs) then this would have been operationally defined as the critical element. It was hypothesized that intonational emphasis on the critical elements would lead to improved comprehension of the structures examined.
Downloaded from las.sagepub.com at MCMASTER UNIV LIBRARY on February 21, 2016
91 lw
EXPERIMENT I
METHOD
_
Sub jects
°‘
‘
-
The subjects consisted of 26 severely subnormal children from two special schools in Cumberland who had been tested on the Sentence Comprehension Test (S.C.T.) and the English Picture Vocabulary Tests (E.P.V.T.) (Brimer and Dunn, 1962) one year prior to the present study. Their vocabulary ages (V.A.) as measured by E.P.V.T. were within the pre-school range (3 : 0 - 4 : 11 ). The chronological age range of the sample was 5 : 10 to 14: 9 with a mean of 9: 11. =
...
&dquo;
Materials
’.
The test consisted of a booklet of black and white picture arrays. For the purpose of the present study five sub-tests, each containing four sentences, were selected to form an abbreviated version of the test. The five sub-tests were not intended to be representative of the test as a whole but were selected for their suitability as a dependent variable. An error analysis of the subjects’ scores on their initial testing agreed with previous analyses in determining the sub-tests for which there were clear These error patterns, i.e. where errors tended to cluster on one picture referent. sub-tests were: Plural e.g. The girls are skipping. Future e.g. The dog is going to jump. Passive e.g. The car is being pushed by the bus. Negative e.g. The boy is not crying. Transitive Negative e.g. The boy is not opening the gate. The italicized words are the critical elements as previously defined. The order of difficulty of the 15 sub-tests of S.C.T. for S.S.N. children shows that the five selected sub-tests were among the more difficult, (Mittler and Wheldall, 1971). An analysis of existing data on S.C.T. showed that scores on the five sub-tests were a reasonably good predictor of scores on the same five sub-tests given two years later (r = 0.63, p
