- Email: [email protected]
Semantic abilities in dementia of the Alzheimer type. II. Grammatical semantics
BRAIN
AND
LANGUAGE
36,
533-542 (1989)
Semantic Abilities in Dementia of the Alzheimer Type II. Grammatical Semantics SHANNE Department
R. SMITH, HELEN J. CHENERY, AND BRUCE E. MURDOCH of Speech and Hearing, University of Queensland, Queensland, Australia
St. Lucia, Q4067,
The grammatical semantic abilities of 18 Alzheimer patients were investigated using picture description tasks and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. During picture description, Alzheimer patients showed that they were able to provide as much information about the target picture as control subjects, but were less concise in their verbal representation of the information. The lack of conciseness was reflected in the DAT patients requiring more time and more syllables to communicate a similar quantity of information than the control subjects. The appropriateness of using a picture description task which involves a perceptual step-by-step account of unrelated events to assess sentential semantics and the conveying of information at a conceptual level is discussed. o 1989 Academic press. Inc.
INTRODUCTION As in the accompanying paper on lexical semantics, we are concerned here with the semantic abilities of patients with dementia of the Alzheimer type (DAT). The lexical semantic study showed that DAT patients have impaired lexical semantic abilities compared to nonneurologicahy impaired institutionalized subjects matched for age, sex, and level of education. The purpose of the present study was to determine whether the noted disturbance in semantic abilities also extends to the grammatical (sentence) level. Hier, Hagenlocker, and Shindler (1985) and Bayles, Tomoeda, Kaszniak, Stern, and Evans (1985) demonstrated that as the severity of DAT increases, the number of relevant observations made and the amount of information conveyed in DAT patients’ speech falls. Speech becomes less concise Address correspondence and reprint requests to Dr. B. E. Murdoch, Head, Department of Speech and Hearing, University of Queensland, St. Lucia, Q4067, Australia. 533 0093-934x/89 $3.00 Copyright 0 1989 by Academic Press, Inc. All rights of reproduction in any form reserved.
534
SMITH, CHENERY,
AND MURDOCH
and there is increased used of empty words and pronouns, etc., accompanied by a reduced speaking rate (Hier et al., 1985; Miller & Hague, 1975). Dementia patients have been described as having the syntactic framework of discourse but little with which to fill it, in that their speech may be grammatically correct even when nearly devoid of meaning (Bayles, 1985; Hier et al., 1985). picture description tasks have been used to quantify some of the changes in DAT patients’ use of lexical and syntactic knowledge (Hier et al., 1985; Nicholas, Obler, Albert, & Helm-Estabrooks, 1985; Seltzer & Sherwin, 1983). Hier et al. (1985) reported that on a picture description task, compared to the speech of normal subjects, the speech of dementia subjects shows a reduction in both lexical diversity (total words used and unique words used) and grammatical complexity. However, the impairment in lexical diversity was more severe than that in grammatical complexity, the latter being well maintained in the early stages of DAT. Their findings confirmed prior suggestions that the lexicon is more vulnerable to disruption in dementia than syntax (Schwartz, Marin, & Saffran, 1979). The present paper adds to the growing body of knowledge regarding the nature of the semantic impairment in DAT. We report the results of three separate analyses of speech samples of DAT patients elicited by means of picture description, two assessments being aimed at the holistic evaluation of how effectively DAT patients convey information at the concept level and a third assessment involving a more defined analysis of grammatical semantic abilities aimed at providing more information about functional structure roles at a phrasal level. METHOD Subjects. The subjects were the 18 DAT patients and 18 control subjects described in the preceding paper (Smith, Murdoch, & Chenery, 1989). Picture description task. A Marantz audiotape recorder (Model C-207 LP) was used to collect each subject’s description of the picture stimuli provided by the Western Aphasia Battery (WAB) (Kertesz, 1982). A lapel microphone was positioned on the collar of the subject’s shirt (or anchored to the subject’s clothing at a similar distance from their mouth). The lapel microphone was used to maximize the intelligibility of the recorded samples, and to reduce patient distraction. Subjects were given the following specific instructions: “Mr./Mrs./Miss . . . , can you see this picture? I want you to tell me everything you see going on in that picture.” The stimulus picture from the WAB was used because it facilitates predictability of output and, therefore, accommodates intersubject comparison, due to the shared frame of reference. The resultant intersubject comparison allowed quantification of the changes in the DAT patient’s use of lexical and sentential semantic knowledge. It was felt that the picture stimulus included in the WAB contained enough detail to allow a normal speaker to talk for at least 45 to 60 set, which was a criterion used by Yorkston and .Beukelman (1980) in their selection of suitable stimuli for analysis. In accordance with the procedure used by Yorkston and Beukelman (1980) no specific time limit was imposed and recording continued until the subjects indicated that they were
GRAMMATICAL
SEMANTIC ABILITIES
IN DEMENTIA
535
finished, or until 30 set of silence elapsed. After that 30-set interval, the subjects were asked if they had finished. The recorded speech samples were transcribed twice to increase the accuracy of the transcription. The speech samples recorded for the picture description task were analyzed using various methods including the Analysis of Speech Samples (ASS) (Yorkston & Beukelman, 1980), Prism G Profile (Crystal, 1982), and Additional Measures provided by Hier et al. (1985). The speech samples of the 18 DAT patients and 18 control subjects were compared using the ASS procedure devised by Yorkston and Beukelman (1980).Although the procedure was not originally designed for use with DAT patients, it was felt that such a procedure may be useful for examining the connected language abilities of these patients due to their relatively preserved syntactic ability in the presence of disturbed semantic ability. The utterances produced by 15 subjects from each group (only 15 of the DAT subjects were able to produce a spontaneous speech sample of sufficient length for analysis) during the picture description task were profiled on the Prism G in accordance with the guidelines provided by Crystal (1982). In addition, appropriate utterances, defined as those utterances semantically related to the theme of the stimulus picture, were profiled separately from idiosyncratic utterances. Idiosyncratic utterances were defined as those utterances which were grammatically well formed, but not semantically related to the theme of the picture. Idiosyncratic and appropriate utterance types were separated to determine if there was any relationship between the grammatical complexity and semantic appropriateness of an utterance. Measures devised by Hier et al. (1985) were used to further analyze the speech samples of the 18 DAT and control subjects. These measures include (a) total number of words, (b) number of unique words, (c) relevant observations, (d) an anomia index, and (e) a conciseness index. Since anomia is characterized by the greater use of pronouns at the expense of proper nouns (Wepman, Bock, Jones, & van Pelt, 1956), Hier et al. (1985) devised an anomia index which was defined as the ratio 1- nouns/(nouns + pronouns). The more anomia demonstrated by the subject, the larger the index. The conciseness was calculated as the ratio (relevant observations/total words) x 100. A greater conciseness of expression is reflected by a larger conciseness index (Hier et al., 1985).
RESULTS
1. Picture description task: Yorkston and Beukelman analysis. Table 1 compares the performances of the control and DAT subjects on the picture description task using the ASS variables. t tests for independent measures using the Bonferroni adjustment (Holm, 1979) to correct for multiplicity of tests (for .05 level of significance, p must be less than .0083) showed that DAT patients took significantly longer to describe the picture and used more syllables than control subjects to express each content unit. Further, DAT patients expressed fewer content units per minute than control subjects. 2. Picture description task: Profile in grammatical semantics. The composition of the appropriate utterances produced by DAT and control subjects during picture description was compared by a series of t tests for independent measures (p < .0063 using Bonferroni adjustment for multiple tests). DAT patients used significantly fewer elements per clause than control subjects [t(28) = 3.49; p < .0063]. However, there was no
84.87 31.53 14.20 99.98 10.13 12.97
f
51.58 87.49 12.68 42.67 5.10 8.47
SD
DAT Group (n = 18)
44.53 87.67 23.13 123.25 31.71 3.88
,f
19.11 55.92 15.44 52.58 12.26 0.67
SD
Control group (n = 18)
40.34 43.86 -8.93 -23.27 -21.58 9.09
Differences between means
2.84 1.64 - 1.73 -1.33 - 6.29 4.14
t
<.0083 NS NS NS <.0083 <.0083
P
Note. DAT, dementia of the Alzheimer’s type; TA, total time; TS, total syllables; TCU, total content units; SM, syllables per minute; CUM, content units per minute; SCU, syllables per content unit; NS, not significant, p > .0083 (Bonferroni adjustment for multiple tests).
TA TS TCU SM CUM scu
Variable
TABLE 1
COMPARISONOF DAT AND CONTROL GROUPSUSING YORKSTON AND BEUKELMAN ANALYSIS
a 3:
B
3
E -2
!z
G
“3
E
GRAMMATICAL
SEMANTIC
ABILITIES
IN DEMENTIA
537
difference in the total number of clauses, elements, specifications, and deictics used by DAT and control subjects to formulate appropriate utterances. The number of specifications and deictics per element were also similar for DAT and control subjects as was the percentage of total utterances comprising appropriate utterances. The composition of idiosyncratic utterances expressed by DAT and control subjects during picture description was also compared by t tests for independent measures. There was no significant difference in the number of clauses, elements, specifications, or deictics used by DAT and control subjects. The complexity of clauses (reflected by the number of elements per clause, specifications per element, and deictics per element) used by the two groups for idiosyncratic utterances was the same. Table 2 shows the comparison of the appropriate and idiosyncratic utterances produced by DAT patients. The means for each Prism-G variable within each utterance type were compared by a t test for related measures (p < .0063 using Bonferroni adjustment for multiple tests). Overall, DAT patients produced significantly more appropriate than idiosyncratic utterances (see Table 2). Similarly, more clauses, elements, and specifications were encoded in appropriate utterances than in idiosyncratic utterances. However, the complexity of the clauses used in appropriate and idiosyncratic utterances was similar, such that there was no difference between the number of elements per clause, specifications per element, or deictics per element used in both types of utterances. A comparison of the appropriate and idiosyncratic utterances produced by control subjects during picture description is also shown in Table 2. Control subjects demonstrated a similar pattern to DAT patients in that appropriate utterances constituted the greater percentage of the total number of utterances expressed. In addition, the analysis showed that significantly more clauses, elements, specifications, deictics, and deictics per element were encoded in appropriate utterances than idiosyncratic. t tests for independent measures using the Bonferroni adjustment to correct for multiple tests (for .05 level of significance p must be less than .Ol) revealed no significant difference between the DAT and control groups on any of the additional measures (total words, unique words, relevant observations, an anomia index, and a conciseness index). DISCUSSION
The present study identified differences between the DAT and control subjects in terms of efficiency of information transference. While a similar amount of information was communicated by DAT subjects, they required more time and a greater number of syllables to encode each concept. Thus, DAT subjects were less concise in their verbal formulations and could be described as loquacious or verbose.
TABLE 2
9.18 24.65 19.66 9.07 0.40 0.23 0.12 12.58 6.54 18.58 19.25 4.15 0.24 0.16 0.09 6.58
11.27 31.27 24.13 6.60 2.79 0.73 0.22 85.67
SD
12.93 30.67 22.93 9.07 2.37 0.76 0.27 71.93
.f
1.93 5.33 2.87 2.07 2.82 0.63 0.39 14.33
3.80 9.80 6.00 3.67 2.46 0.66 0.37 22.07
f
0.96 2.55 1.19 1.22 0.71 0.30 0.10 6.58
2.62 7.79 5.22 3.06 0.54 0.55 0.16 12.58
SD
Idio. utterances
9.34 25.94 21.26 4.53 -0.03 0.10 -0.17 71.34
9.13 20.81 16.93 5.40 -0.09 0.10 -0.10 55.86
Differences between means
5.21 5.24 4.36 3.93 -0.16 1.42 -4.52 21.01
3.69 3.17 3.38 2.16 -0.56 0.09 -1.77 8.60
t
NS c.0063 <.0063
<.0063 <.0063 <.04x3 NS NS NS NS QlO63
P
Note. DAT, dementia of the Alzheimer’s type; PRISM G, profile in grammatical semantics (Crystal, 1982); NS, not significant, p > .0063 (Bonferroni adjustment for multiple tests).
DAT subjects (n = 15) Clause (C) Elements (E) Specifications (Sp) Deictics (D) WC SP/E D/E % of total utterances Control subjects (n = 15) Clause (C) Elements (E) Specifications (Sp) Deictics (D) WC SPIE WE % of total utterances
PRISM G Variable
App. utterances
COMPARISONOF THE COMHXITION OF APPROPRIATE(APP.) AND IDIOSYNCRATIC(1~10.) UTTERANCES PRODUCEDBY DAT AND CONTROL SUBJECTSDURING PICTURE DESCRIPTION
G
R Fi E4 “4
E “Z
GRAMMATICAL
SEMANTIC
ABILITIES
IN DEMENTIA
539
Similarly, Constantinidis, Richards, and de Ajuriaguerra (1978) reported that the language in DAT is characterized by a superfluity of words and suggestedthat such overabundance of words may reflect the DAT patients’ need to qualify their utterances. Indeed, in the present study, the DAT subjects’ superfluity of expression was exemplified by circumlocutory behavior in an attempt to supply the right word. For example, one DAT patient referred to the flagpole in the picture stimulus as: “The place where you put flags up.” DAT patients in the present study provided the same amount of information on the picture description task as control subjects, as measured by total content units and relevant observations. This is in contrast to the findings of Nicholas et al. (1985) who found that control subjects produce significantly more content units than DAT patients. The discrepancy may reflect the differing picture stimuli used in the Nicholas et al. (1985) and the present study [i.e., the Cookie Theft picture (Goodglass & Kaplan, 1983) and the WAB picture, respectively]. It is our contention that picture stimuli that require a holistic integration of linguistic and nonlinguistic information at a conceptual or message level representation (Garrett, 1982), such that inferential or cause-effect analyses are assessed in the formation of a narrative, would be more likely to identify the language deficits associated with DAT. Indeed, the Cookie Theft picture requires, to some extent, this type of inferential reasoning (e.g., The boy is stealing the cookies while his mother’s attention is diverted and, in his haste, is overbalancing on the stool). By contrast, the WAB picture assesses only a step-by-step perceptual account of events, with no relationship existing between the concepts. Anomia has been identified as a feature of DAT patients’ connected speech, based on the observation that DAT patients produce more pronouns and more deictic terms than control subjects (Nicholas et al., 1985). The Prism G analysis identified a large number of pronouns and deictic terms used by both DAT patients and controls in the present study which again may be partly attributed to the nature of the stimulus picture. The WAB picture includes a number of characters involved in a variety of activities. Consequently, the subject must use a number of indefinite personal pronouns because the people in the picture remain unidentified with respect to name or vocation. Perhaps the problem may be overcome by the examiner introducing names or occupations for the characters. A qualitative analysis of DAT subjects’ transcriptions, however, did point to a loss of precision manifest in the use of indefinite terms. Examples of imprecise utterances produced by DAT patients during picture description include “This one up at there, and this one down here”; “Well, this one up with a lot of things in it.” The anomia evident in DAT is further exemplified by the substitution of symbolic noises in circumlocutory utterances, such as in the following
540
SMITH,
CHENERY,
AND
MURDOCH
utterance produced by one DAT patient in the present study: “I don’t know what they do all that bang bang business for.” It appears that the use of an analysis such as the Prism G to document difficulties in grammatical semantics may not be appropriate given the DAT patients’ relatively superior syntactic abilities which serve to mask the impairment in semantics. Obler and Albert (1981) noted that, during the early stages of DAT, patients express uncertainty in their responses to picture description tasks. DAT patients evidenced such behavior in the present study, producing the following examples during picture description: “Those look like a shoe, his shoes, is it?“; “There’s those two I’m not sure of”; “There’s a sheep, I think.” Another feature described by Obler and Albert (1981), which was demonstrated by the DAT patients in the present study, is the repetition of ideas. Sometimes, the patients acknowledged the repetition of a previous utterance, e.g., “The boy’s flying a kite, as I said before.” Other repetitions were provided without such acknowledgement from the DAT patient. Horner (1985) identified similar repetitions of ideas and the use of stereotype phrases in the connected speech of their DAT patients. One DAT patient in the present study lapsed into the nursery rhyme “Mary had a little lamb” after describing the lamb in the picture (many DAT and control subjects described the dog in the WAB picture as a lamb). As noted, Bayles et al. (1985) found that such repetition of an idea after an intervening response was the most common form of perseveration for each group of DAT patients they examined. DAT patients also exhibited other circumlocutory reformulations of utterances, e.g., “The man and his girlfriend are having an af- having a snack.” The number of deictics per element used by DAT and control subjects was the same, suggesting that both subject groups use deictic items as a means of avoiding more specific lexemes. This feature of DAT may be more closely related to the effects of normal aging as Ulatowska, Hayashi, Cannito, and Fleming (1985) demonstrated that a group of normal aged persons (age 77-92) produced significantly greater ambiguity of reference because of the increased use of deictic terms than either a younger elderly (age 64-76) or a middle-aged group (age 27-65). The analysis of sentential semantics produced in response to a picture stimulus demonstrated that control subjects’ appropriate utterances contained greater complexity and length, reflected by the number of elements per clause, than DAT subjects. This difference points to the DAT subjects impairment in mapping functional structure roles at an appropriately complex phrasal level. Of interest also is that the control group produced fewer elements per clause (2.79) than would be expected of a normal population communicating in an unconstrained situation [e.g., in unstructured discourse where a greater number of embedded (Level 5) sentences would be produced]. The appropriateness of the WAB picture is again
GRAMMATICAL
SEMANTIC ABILITIES
IN DEMENTIA
541
questioned given the control subjects reliance on simpler constructions that could adequately convey the information required. It would appear that in the analysis of sentential semantics, the advantages of a shared frame of reference between the subject and the researcher which contributes to a more objective interpretation of performance are outweighed by the limitations that picture description tasks place on the formulations of complex sentences. CONCLUSIONS
The present study identified differences between the semantic language abilities of DAT and normally aging subjects using a picture description task. Some language abilities demonstrated by DAT patients (e.g., disruption of reference manifest in the overuse of deictic terms) appeared to be exaggerations of those exhibited by normal aging subjects. Differences between the language abilities of DAT and elderly subjects are, however, also evident and reflect an impairment in formulating appropriately complex functional structure roles at the phrasal level, and a reduced conciseness of expression. The present study served more to identify methodological flaws in the assessment of the grammatical semantic abilities of DAT patients. In particular, the choice of picture stimuli used in the analysis of sentential semantics, as well as the analysis itself, must be carefully considered, such that the picture allows sufficient scope for the assessmentof inferential or narrative formation, rather than a concrete perceptual description of events. In addition, the nature of the task should be sufficiently taxing on the DAT patients’ impaired semantic system, such that recourse to their more spared syntactic system does not enhance their performance. REFERENCES Bayles, K. A. 1985. Communication in dementia. In H. K. Ulatowska (Ed.), The aging brain: Communication in the elderly. London: Taylor & Francis. Bayles, K. A., Tomoeda, C. K., Kaszniak, A. W., Stern, L. Z., & Evans, K. K. 1985. Verbal perseveration of dementia patients. Brain and Language, 25, 102-l 16. Constantinidis, J., Richards, J., & de Ajuriaguerra, J. 1978. Dementias with senile plaques and neurofibrillary changes. In A. D. Isaacs & F. Post (Eds.), Studies in geriatric psychiatry. Brisbane: Wiley. Crystal, D. 1982. Projiling linguistic disability. London: Arnold. Garrett, M. F. 1982. Production of speech: Observations from normal and pathological language use. In A. W. Ellis (Ed.), Normality and pathology in cognitive functions. New York/London: Academic Press. Goodglass, H., & Kaplan, E. 1983. The assessment of aphasia and related disorders. Philadelphia: Lea & Febiger. Hier, D. B., Hagenlocker, K., & Shindler, A. G. 1985.Language disintegration in dementia: Effects of etiology and severity. Brain and Language, 25, 117-133. Holm, S. 1979. A simple sequentially rejective multiple test procedure. Scandinavian Journal
of Statistics,
6, 65-70.
Homer, J. 1985. Language disorders associated with Alzheimer’s disease, left hemisphere
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stroke, and progressive illness of uncertain etiology. In R. H. Brookshire (Ed.), Clinical Aphasiofogy Conference Proceedings. Minneapolis: BRK Publishers. Kertesz, A. 1982. Western aphasia battery. New York: Grune & Stratton. Miller, E., & Hague, F. 1975.Some characteristics of verbal behaviour in presenile dementia. Psychological Medicine, 5, 255-259. Nicholas, M., Obler, L. K., Albert, M. L., & Helm-Estabrooks, N. 1985. Empty speech in Alzheimer’s disease and fluent aphasia. Journal of Speech and Hearing Research, 28, 405-410. Obler, L. K., & Albert, M. L. 1981. Language in the elderly aphasic and in the dementing patient. In M. T. Samo (Ed.), Acquired aphasia. New York: Academic Press. Schwartz, M. F., Marin, 0. S. M., & Satfran, E. M. 1979. Dissociations of language function in dementia: A case study. Brain and Language, 7, 277-306. Seltzer, B., & Sherwin, I. 1983. A comparison of clinical features in early and later onset primary degenerative dementia. Archives of Neurology, 40, 143-146. Smith, S. R., Murdoch, B. E., & Chenery, H. J. 1989. Semantic abilities in dementia of the Alzheimer type. I. Lexical semantics. Brain and Language, 36, 314-324. Ulatowska, H. K., Cannito, M. P., Hayashi, M. M., & Fleming, S. G. 1985. Language abilities in the elderly. In H. K. Ulatowska (Ed.), The aging brain: Communication in the elderly. London: Taylor & Francis. Wepman, J. M., Bock, R. D., Jones, L. V., & van Pelt, D. 1956. Psycholinguistic study of aphasia: A revision of the concept of anomia. Journal of Speech and Hearing Disorders, 21, 469-477. Yorkston, K. M., & Beukelman, D. R. 1980. An analysis of connected speech samples of aphasic and normal speakers. Journal of Speech and Hearing Disorders, 45, 2736.
AND
LANGUAGE
36,
533-542 (1989)
Semantic Abilities in Dementia of the Alzheimer Type II. Grammatical Semantics SHANNE Department
R. SMITH, HELEN J. CHENERY, AND BRUCE E. MURDOCH of Speech and Hearing, University of Queensland, Queensland, Australia
St. Lucia, Q4067,
The grammatical semantic abilities of 18 Alzheimer patients were investigated using picture description tasks and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. During picture description, Alzheimer patients showed that they were able to provide as much information about the target picture as control subjects, but were less concise in their verbal representation of the information. The lack of conciseness was reflected in the DAT patients requiring more time and more syllables to communicate a similar quantity of information than the control subjects. The appropriateness of using a picture description task which involves a perceptual step-by-step account of unrelated events to assess sentential semantics and the conveying of information at a conceptual level is discussed. o 1989 Academic press. Inc.
INTRODUCTION As in the accompanying paper on lexical semantics, we are concerned here with the semantic abilities of patients with dementia of the Alzheimer type (DAT). The lexical semantic study showed that DAT patients have impaired lexical semantic abilities compared to nonneurologicahy impaired institutionalized subjects matched for age, sex, and level of education. The purpose of the present study was to determine whether the noted disturbance in semantic abilities also extends to the grammatical (sentence) level. Hier, Hagenlocker, and Shindler (1985) and Bayles, Tomoeda, Kaszniak, Stern, and Evans (1985) demonstrated that as the severity of DAT increases, the number of relevant observations made and the amount of information conveyed in DAT patients’ speech falls. Speech becomes less concise Address correspondence and reprint requests to Dr. B. E. Murdoch, Head, Department of Speech and Hearing, University of Queensland, St. Lucia, Q4067, Australia. 533 0093-934x/89 $3.00 Copyright 0 1989 by Academic Press, Inc. All rights of reproduction in any form reserved.
534
SMITH, CHENERY,
AND MURDOCH
and there is increased used of empty words and pronouns, etc., accompanied by a reduced speaking rate (Hier et al., 1985; Miller & Hague, 1975). Dementia patients have been described as having the syntactic framework of discourse but little with which to fill it, in that their speech may be grammatically correct even when nearly devoid of meaning (Bayles, 1985; Hier et al., 1985). picture description tasks have been used to quantify some of the changes in DAT patients’ use of lexical and syntactic knowledge (Hier et al., 1985; Nicholas, Obler, Albert, & Helm-Estabrooks, 1985; Seltzer & Sherwin, 1983). Hier et al. (1985) reported that on a picture description task, compared to the speech of normal subjects, the speech of dementia subjects shows a reduction in both lexical diversity (total words used and unique words used) and grammatical complexity. However, the impairment in lexical diversity was more severe than that in grammatical complexity, the latter being well maintained in the early stages of DAT. Their findings confirmed prior suggestions that the lexicon is more vulnerable to disruption in dementia than syntax (Schwartz, Marin, & Saffran, 1979). The present paper adds to the growing body of knowledge regarding the nature of the semantic impairment in DAT. We report the results of three separate analyses of speech samples of DAT patients elicited by means of picture description, two assessments being aimed at the holistic evaluation of how effectively DAT patients convey information at the concept level and a third assessment involving a more defined analysis of grammatical semantic abilities aimed at providing more information about functional structure roles at a phrasal level. METHOD Subjects. The subjects were the 18 DAT patients and 18 control subjects described in the preceding paper (Smith, Murdoch, & Chenery, 1989). Picture description task. A Marantz audiotape recorder (Model C-207 LP) was used to collect each subject’s description of the picture stimuli provided by the Western Aphasia Battery (WAB) (Kertesz, 1982). A lapel microphone was positioned on the collar of the subject’s shirt (or anchored to the subject’s clothing at a similar distance from their mouth). The lapel microphone was used to maximize the intelligibility of the recorded samples, and to reduce patient distraction. Subjects were given the following specific instructions: “Mr./Mrs./Miss . . . , can you see this picture? I want you to tell me everything you see going on in that picture.” The stimulus picture from the WAB was used because it facilitates predictability of output and, therefore, accommodates intersubject comparison, due to the shared frame of reference. The resultant intersubject comparison allowed quantification of the changes in the DAT patient’s use of lexical and sentential semantic knowledge. It was felt that the picture stimulus included in the WAB contained enough detail to allow a normal speaker to talk for at least 45 to 60 set, which was a criterion used by Yorkston and .Beukelman (1980) in their selection of suitable stimuli for analysis. In accordance with the procedure used by Yorkston and Beukelman (1980) no specific time limit was imposed and recording continued until the subjects indicated that they were
GRAMMATICAL
SEMANTIC ABILITIES
IN DEMENTIA
535
finished, or until 30 set of silence elapsed. After that 30-set interval, the subjects were asked if they had finished. The recorded speech samples were transcribed twice to increase the accuracy of the transcription. The speech samples recorded for the picture description task were analyzed using various methods including the Analysis of Speech Samples (ASS) (Yorkston & Beukelman, 1980), Prism G Profile (Crystal, 1982), and Additional Measures provided by Hier et al. (1985). The speech samples of the 18 DAT patients and 18 control subjects were compared using the ASS procedure devised by Yorkston and Beukelman (1980).Although the procedure was not originally designed for use with DAT patients, it was felt that such a procedure may be useful for examining the connected language abilities of these patients due to their relatively preserved syntactic ability in the presence of disturbed semantic ability. The utterances produced by 15 subjects from each group (only 15 of the DAT subjects were able to produce a spontaneous speech sample of sufficient length for analysis) during the picture description task were profiled on the Prism G in accordance with the guidelines provided by Crystal (1982). In addition, appropriate utterances, defined as those utterances semantically related to the theme of the stimulus picture, were profiled separately from idiosyncratic utterances. Idiosyncratic utterances were defined as those utterances which were grammatically well formed, but not semantically related to the theme of the picture. Idiosyncratic and appropriate utterance types were separated to determine if there was any relationship between the grammatical complexity and semantic appropriateness of an utterance. Measures devised by Hier et al. (1985) were used to further analyze the speech samples of the 18 DAT and control subjects. These measures include (a) total number of words, (b) number of unique words, (c) relevant observations, (d) an anomia index, and (e) a conciseness index. Since anomia is characterized by the greater use of pronouns at the expense of proper nouns (Wepman, Bock, Jones, & van Pelt, 1956), Hier et al. (1985) devised an anomia index which was defined as the ratio 1- nouns/(nouns + pronouns). The more anomia demonstrated by the subject, the larger the index. The conciseness was calculated as the ratio (relevant observations/total words) x 100. A greater conciseness of expression is reflected by a larger conciseness index (Hier et al., 1985).
RESULTS
1. Picture description task: Yorkston and Beukelman analysis. Table 1 compares the performances of the control and DAT subjects on the picture description task using the ASS variables. t tests for independent measures using the Bonferroni adjustment (Holm, 1979) to correct for multiplicity of tests (for .05 level of significance, p must be less than .0083) showed that DAT patients took significantly longer to describe the picture and used more syllables than control subjects to express each content unit. Further, DAT patients expressed fewer content units per minute than control subjects. 2. Picture description task: Profile in grammatical semantics. The composition of the appropriate utterances produced by DAT and control subjects during picture description was compared by a series of t tests for independent measures (p < .0063 using Bonferroni adjustment for multiple tests). DAT patients used significantly fewer elements per clause than control subjects [t(28) = 3.49; p < .0063]. However, there was no
84.87 31.53 14.20 99.98 10.13 12.97
f
51.58 87.49 12.68 42.67 5.10 8.47
SD
DAT Group (n = 18)
44.53 87.67 23.13 123.25 31.71 3.88
,f
19.11 55.92 15.44 52.58 12.26 0.67
SD
Control group (n = 18)
40.34 43.86 -8.93 -23.27 -21.58 9.09
Differences between means
2.84 1.64 - 1.73 -1.33 - 6.29 4.14
t
<.0083 NS NS NS <.0083 <.0083
P
Note. DAT, dementia of the Alzheimer’s type; TA, total time; TS, total syllables; TCU, total content units; SM, syllables per minute; CUM, content units per minute; SCU, syllables per content unit; NS, not significant, p > .0083 (Bonferroni adjustment for multiple tests).
TA TS TCU SM CUM scu
Variable
TABLE 1
COMPARISONOF DAT AND CONTROL GROUPSUSING YORKSTON AND BEUKELMAN ANALYSIS
a 3:
B
3
E -2
!z
G
“3
E
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difference in the total number of clauses, elements, specifications, and deictics used by DAT and control subjects to formulate appropriate utterances. The number of specifications and deictics per element were also similar for DAT and control subjects as was the percentage of total utterances comprising appropriate utterances. The composition of idiosyncratic utterances expressed by DAT and control subjects during picture description was also compared by t tests for independent measures. There was no significant difference in the number of clauses, elements, specifications, or deictics used by DAT and control subjects. The complexity of clauses (reflected by the number of elements per clause, specifications per element, and deictics per element) used by the two groups for idiosyncratic utterances was the same. Table 2 shows the comparison of the appropriate and idiosyncratic utterances produced by DAT patients. The means for each Prism-G variable within each utterance type were compared by a t test for related measures (p < .0063 using Bonferroni adjustment for multiple tests). Overall, DAT patients produced significantly more appropriate than idiosyncratic utterances (see Table 2). Similarly, more clauses, elements, and specifications were encoded in appropriate utterances than in idiosyncratic utterances. However, the complexity of the clauses used in appropriate and idiosyncratic utterances was similar, such that there was no difference between the number of elements per clause, specifications per element, or deictics per element used in both types of utterances. A comparison of the appropriate and idiosyncratic utterances produced by control subjects during picture description is also shown in Table 2. Control subjects demonstrated a similar pattern to DAT patients in that appropriate utterances constituted the greater percentage of the total number of utterances expressed. In addition, the analysis showed that significantly more clauses, elements, specifications, deictics, and deictics per element were encoded in appropriate utterances than idiosyncratic. t tests for independent measures using the Bonferroni adjustment to correct for multiple tests (for .05 level of significance p must be less than .Ol) revealed no significant difference between the DAT and control groups on any of the additional measures (total words, unique words, relevant observations, an anomia index, and a conciseness index). DISCUSSION
The present study identified differences between the DAT and control subjects in terms of efficiency of information transference. While a similar amount of information was communicated by DAT subjects, they required more time and a greater number of syllables to encode each concept. Thus, DAT subjects were less concise in their verbal formulations and could be described as loquacious or verbose.
TABLE 2
9.18 24.65 19.66 9.07 0.40 0.23 0.12 12.58 6.54 18.58 19.25 4.15 0.24 0.16 0.09 6.58
11.27 31.27 24.13 6.60 2.79 0.73 0.22 85.67
SD
12.93 30.67 22.93 9.07 2.37 0.76 0.27 71.93
.f
1.93 5.33 2.87 2.07 2.82 0.63 0.39 14.33
3.80 9.80 6.00 3.67 2.46 0.66 0.37 22.07
f
0.96 2.55 1.19 1.22 0.71 0.30 0.10 6.58
2.62 7.79 5.22 3.06 0.54 0.55 0.16 12.58
SD
Idio. utterances
9.34 25.94 21.26 4.53 -0.03 0.10 -0.17 71.34
9.13 20.81 16.93 5.40 -0.09 0.10 -0.10 55.86
Differences between means
5.21 5.24 4.36 3.93 -0.16 1.42 -4.52 21.01
3.69 3.17 3.38 2.16 -0.56 0.09 -1.77 8.60
t
NS c.0063 <.0063
<.0063 <.0063 <.04x3 NS NS NS NS QlO63
P
Note. DAT, dementia of the Alzheimer’s type; PRISM G, profile in grammatical semantics (Crystal, 1982); NS, not significant, p > .0063 (Bonferroni adjustment for multiple tests).
DAT subjects (n = 15) Clause (C) Elements (E) Specifications (Sp) Deictics (D) WC SP/E D/E % of total utterances Control subjects (n = 15) Clause (C) Elements (E) Specifications (Sp) Deictics (D) WC SPIE WE % of total utterances
PRISM G Variable
App. utterances
COMPARISONOF THE COMHXITION OF APPROPRIATE(APP.) AND IDIOSYNCRATIC(1~10.) UTTERANCES PRODUCEDBY DAT AND CONTROL SUBJECTSDURING PICTURE DESCRIPTION
G
R Fi E4 “4
E “Z
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Similarly, Constantinidis, Richards, and de Ajuriaguerra (1978) reported that the language in DAT is characterized by a superfluity of words and suggestedthat such overabundance of words may reflect the DAT patients’ need to qualify their utterances. Indeed, in the present study, the DAT subjects’ superfluity of expression was exemplified by circumlocutory behavior in an attempt to supply the right word. For example, one DAT patient referred to the flagpole in the picture stimulus as: “The place where you put flags up.” DAT patients in the present study provided the same amount of information on the picture description task as control subjects, as measured by total content units and relevant observations. This is in contrast to the findings of Nicholas et al. (1985) who found that control subjects produce significantly more content units than DAT patients. The discrepancy may reflect the differing picture stimuli used in the Nicholas et al. (1985) and the present study [i.e., the Cookie Theft picture (Goodglass & Kaplan, 1983) and the WAB picture, respectively]. It is our contention that picture stimuli that require a holistic integration of linguistic and nonlinguistic information at a conceptual or message level representation (Garrett, 1982), such that inferential or cause-effect analyses are assessed in the formation of a narrative, would be more likely to identify the language deficits associated with DAT. Indeed, the Cookie Theft picture requires, to some extent, this type of inferential reasoning (e.g., The boy is stealing the cookies while his mother’s attention is diverted and, in his haste, is overbalancing on the stool). By contrast, the WAB picture assesses only a step-by-step perceptual account of events, with no relationship existing between the concepts. Anomia has been identified as a feature of DAT patients’ connected speech, based on the observation that DAT patients produce more pronouns and more deictic terms than control subjects (Nicholas et al., 1985). The Prism G analysis identified a large number of pronouns and deictic terms used by both DAT patients and controls in the present study which again may be partly attributed to the nature of the stimulus picture. The WAB picture includes a number of characters involved in a variety of activities. Consequently, the subject must use a number of indefinite personal pronouns because the people in the picture remain unidentified with respect to name or vocation. Perhaps the problem may be overcome by the examiner introducing names or occupations for the characters. A qualitative analysis of DAT subjects’ transcriptions, however, did point to a loss of precision manifest in the use of indefinite terms. Examples of imprecise utterances produced by DAT patients during picture description include “This one up at there, and this one down here”; “Well, this one up with a lot of things in it.” The anomia evident in DAT is further exemplified by the substitution of symbolic noises in circumlocutory utterances, such as in the following
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utterance produced by one DAT patient in the present study: “I don’t know what they do all that bang bang business for.” It appears that the use of an analysis such as the Prism G to document difficulties in grammatical semantics may not be appropriate given the DAT patients’ relatively superior syntactic abilities which serve to mask the impairment in semantics. Obler and Albert (1981) noted that, during the early stages of DAT, patients express uncertainty in their responses to picture description tasks. DAT patients evidenced such behavior in the present study, producing the following examples during picture description: “Those look like a shoe, his shoes, is it?“; “There’s those two I’m not sure of”; “There’s a sheep, I think.” Another feature described by Obler and Albert (1981), which was demonstrated by the DAT patients in the present study, is the repetition of ideas. Sometimes, the patients acknowledged the repetition of a previous utterance, e.g., “The boy’s flying a kite, as I said before.” Other repetitions were provided without such acknowledgement from the DAT patient. Horner (1985) identified similar repetitions of ideas and the use of stereotype phrases in the connected speech of their DAT patients. One DAT patient in the present study lapsed into the nursery rhyme “Mary had a little lamb” after describing the lamb in the picture (many DAT and control subjects described the dog in the WAB picture as a lamb). As noted, Bayles et al. (1985) found that such repetition of an idea after an intervening response was the most common form of perseveration for each group of DAT patients they examined. DAT patients also exhibited other circumlocutory reformulations of utterances, e.g., “The man and his girlfriend are having an af- having a snack.” The number of deictics per element used by DAT and control subjects was the same, suggesting that both subject groups use deictic items as a means of avoiding more specific lexemes. This feature of DAT may be more closely related to the effects of normal aging as Ulatowska, Hayashi, Cannito, and Fleming (1985) demonstrated that a group of normal aged persons (age 77-92) produced significantly greater ambiguity of reference because of the increased use of deictic terms than either a younger elderly (age 64-76) or a middle-aged group (age 27-65). The analysis of sentential semantics produced in response to a picture stimulus demonstrated that control subjects’ appropriate utterances contained greater complexity and length, reflected by the number of elements per clause, than DAT subjects. This difference points to the DAT subjects impairment in mapping functional structure roles at an appropriately complex phrasal level. Of interest also is that the control group produced fewer elements per clause (2.79) than would be expected of a normal population communicating in an unconstrained situation [e.g., in unstructured discourse where a greater number of embedded (Level 5) sentences would be produced]. The appropriateness of the WAB picture is again
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questioned given the control subjects reliance on simpler constructions that could adequately convey the information required. It would appear that in the analysis of sentential semantics, the advantages of a shared frame of reference between the subject and the researcher which contributes to a more objective interpretation of performance are outweighed by the limitations that picture description tasks place on the formulations of complex sentences. CONCLUSIONS
The present study identified differences between the semantic language abilities of DAT and normally aging subjects using a picture description task. Some language abilities demonstrated by DAT patients (e.g., disruption of reference manifest in the overuse of deictic terms) appeared to be exaggerations of those exhibited by normal aging subjects. Differences between the language abilities of DAT and elderly subjects are, however, also evident and reflect an impairment in formulating appropriately complex functional structure roles at the phrasal level, and a reduced conciseness of expression. The present study served more to identify methodological flaws in the assessment of the grammatical semantic abilities of DAT patients. In particular, the choice of picture stimuli used in the analysis of sentential semantics, as well as the analysis itself, must be carefully considered, such that the picture allows sufficient scope for the assessmentof inferential or narrative formation, rather than a concrete perceptual description of events. In addition, the nature of the task should be sufficiently taxing on the DAT patients’ impaired semantic system, such that recourse to their more spared syntactic system does not enhance their performance. REFERENCES Bayles, K. A. 1985. Communication in dementia. In H. K. Ulatowska (Ed.), The aging brain: Communication in the elderly. London: Taylor & Francis. Bayles, K. A., Tomoeda, C. K., Kaszniak, A. W., Stern, L. Z., & Evans, K. K. 1985. Verbal perseveration of dementia patients. Brain and Language, 25, 102-l 16. Constantinidis, J., Richards, J., & de Ajuriaguerra, J. 1978. Dementias with senile plaques and neurofibrillary changes. In A. D. Isaacs & F. Post (Eds.), Studies in geriatric psychiatry. Brisbane: Wiley. Crystal, D. 1982. Projiling linguistic disability. London: Arnold. Garrett, M. F. 1982. Production of speech: Observations from normal and pathological language use. In A. W. Ellis (Ed.), Normality and pathology in cognitive functions. New York/London: Academic Press. Goodglass, H., & Kaplan, E. 1983. The assessment of aphasia and related disorders. Philadelphia: Lea & Febiger. Hier, D. B., Hagenlocker, K., & Shindler, A. G. 1985.Language disintegration in dementia: Effects of etiology and severity. Brain and Language, 25, 117-133. Holm, S. 1979. A simple sequentially rejective multiple test procedure. Scandinavian Journal
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stroke, and progressive illness of uncertain etiology. In R. H. Brookshire (Ed.), Clinical Aphasiofogy Conference Proceedings. Minneapolis: BRK Publishers. Kertesz, A. 1982. Western aphasia battery. New York: Grune & Stratton. Miller, E., & Hague, F. 1975.Some characteristics of verbal behaviour in presenile dementia. Psychological Medicine, 5, 255-259. Nicholas, M., Obler, L. K., Albert, M. L., & Helm-Estabrooks, N. 1985. Empty speech in Alzheimer’s disease and fluent aphasia. Journal of Speech and Hearing Research, 28, 405-410. Obler, L. K., & Albert, M. L. 1981. Language in the elderly aphasic and in the dementing patient. In M. T. Samo (Ed.), Acquired aphasia. New York: Academic Press. Schwartz, M. F., Marin, 0. S. M., & Satfran, E. M. 1979. Dissociations of language function in dementia: A case study. Brain and Language, 7, 277-306. Seltzer, B., & Sherwin, I. 1983. A comparison of clinical features in early and later onset primary degenerative dementia. Archives of Neurology, 40, 143-146. Smith, S. R., Murdoch, B. E., & Chenery, H. J. 1989. Semantic abilities in dementia of the Alzheimer type. I. Lexical semantics. Brain and Language, 36, 314-324. Ulatowska, H. K., Cannito, M. P., Hayashi, M. M., & Fleming, S. G. 1985. Language abilities in the elderly. In H. K. Ulatowska (Ed.), The aging brain: Communication in the elderly. London: Taylor & Francis. Wepman, J. M., Bock, R. D., Jones, L. V., & van Pelt, D. 1956. Psycholinguistic study of aphasia: A revision of the concept of anomia. Journal of Speech and Hearing Disorders, 21, 469-477. Yorkston, K. M., & Beukelman, D. R. 1980. An analysis of connected speech samples of aphasic and normal speakers. Journal of Speech and Hearing Disorders, 45, 2736.