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Features of agrammatism in Polish — A case study
~l~~/~ 53.00+ .oo @ 1988 Pergamon Press pk
J. ~~f~z~, Volume 3, Number 1, pp. 7748.1988. Printed in Great Britain
Features of Agrammatism in Polish -ACmeStudy Hanna K. Ulatowska University of Texas at ~a~~~ Dallas
Maria Sadowska PO&~ Academy of Sciences and Medical School Warsaw
AB!STRACT Much l-ecentresearch in aphasia has been devoted to the characterimtion of the syndrome of agrammatism. At the same time, it has become increasingly clear that at least some aphasic syndromes and most notably agrammatism am deficits which am most precisely described along grammatical lines rather than according to the various linguistic activites such as comprehension, reading and writing. The realization that aphasic deficits are selective along grammatical lines has important consequences, since it provides us with an excellent op~~u~ty to bridge the gap between theories of language structure and aphasiology. The interest in agrammatism has in turn led to expanding the studies to languages representing different structural types in order to explore the effect of the specific structure on the disruption of language in aphasia. This article will deal with the issue of the selectivity of grammatical breakdown and the dissociation between various grammatical subcomponents in the language of a Polish agrammatic patient who has been studied longitudinally for the last three years. More specifically, the selectivity of the im~ent of the Sectional mo~holo~ with relative preservation of derivationa morphology will be discussed. A@ the dissociation between the preservation of syntactic order and impairment in syntactic agreement and government in the same aphasic patient are described.
INTRODUCTION
In studying the relationship between brain and language, most aphasiologists assume that the patterns of dissociation observed in different aphasic I syndromes represent decomposition of a universal language processing system. And yet, most contemporary research on aphasia has been carried out exclusively in English, resulting in a confounding between language-specific content and universal m~ha~sms. However, some recent work on crosslinguistic studies in aphasia (MacWhinney and Bates in press; Menn and Obler 1987) suggest more differentiation as a function of language type with few differences in the nature of grammatical breakdown among patients groups.
78
Joumal of Neurollnguirtics, Volume 3, Nlnnber l(l988)
These studies indicate that the “same” aphasic syndromes look very different from one language to another. In fact, language differences account for more variance than patient group differences. Another set of facts which emerges from these studies deals with the characterization of grammatical breakdown in aphasia, which provides strong evidence for a selectively greater impairment of grammatical inflections and function words than other aspects of language. This selective vulnerability of morphology is not restricted to agrammatics, but occurs in different patient groups. It is apparent that the vulnerability of morphology is especially evident in highly inflectional languages. However, despite this vulnerability of morphology, aphasic patients still seem to preserve a great deal of information about the “morphological shape” of their language. Also, although the contrast between agrammatism and paragrammatism seems useful in English where omission is the option most often elected by an agrammatic patient, the distinction breaks down in a richly inflected language where substitution is the most common type of error for both fluent and non-fluent aphasics. The most common substitution errors are within-class substitutions. Patients do not, for example, place verb inflections on a noun. Furthermore, within a broad class they rarely make substitutions between different subclasses. Although substitution and omission errors both occur, no evidence has been found to date for violations of morpheme order. The studies of sentence comprehension indicate that aphasic patients preserve control over morphology in comprehension that is proportional to the strength of morphology in their native language. At the same time, however, the closed class elements are selectively vulnerable to brain damage even in languages with a strong morphology. In general, the results of the studies of comprehension of morphology parallel the results for sentence production in every way, including the surprising lack of difference across patient groups (Bates et al. 1987, in press). Finally, the above studies indicate that the best way to characterize the breakdown of morphology is in terms of access rather than loss. That is, patients show an ability to retrieve and use morphological patterns correctly when there is enough redundancy in semantic-pragmatic functions or syntacticmorphological context. All of the above information indicates the need for further research focused specifically on morphology in a richly inflected language. The basic question which can be posed then is: what constraints does the “morphological shape” of a language place on the range of symptoms observed in fluent and nonfluent aphasia? In order to address some of the issues raised above, a single case study will be presented. As Caplan (1986) stated recently, “Single case analyses provide the
best opportunity for studying language pathology in detail and there is no replacement for detailed single case analysis if one’s goal is to document a particular deficit in an individual.” This study presents a Wemicke’s aphasic who is a native speaker of Polish, a richly in&&d language. The patient is capable of producing large amounts of language in both spoken and written modalities. The patient presents aphasia which is primarily characterized by breakdown of morphology. Since the patient exhibited a rich pattern of morphological breakdown, we decided to study her longitudinally. We feel that the vast data accumulated has revealed some facts to us about the nature of the breakdown of language and has allowed us to speculate about some generalizations to fluent aphasias in highly inIIectiona1 languages. Before proceeding to the description of the case, a brief characterization of the morphological system in the Polish language will be given. All inflectional word classes are marked by sufhxes which indicate the following categories: in nouns, gender, number, case, and d~lension; in adjectives, gender, number, and case; in verbs, number, person, gender, tense, and aspect. Additionally, aspect is marked on some verbs by prefixes. There is a rich system of derivational morphology which is marked by suflixes. Stems of inflectional and derivational forms undergo many morphophonemic changes. Inflectional forms function syntactically in structures of agreement and government. Agreement occurs between nouns and their modifying adjectives according to gender, number and case, and between subjects and their predicates in person and number, and in gender in some tenses. Government occurs between a governing word such as verb or preposition and the noun that follows marked by a given case. Up to now there has been only one published study dealing specifically with impairment of mo~holo~ in agr~matism in Polish ~orn~~ka-Volo~~ 1976). The results of the study showed that breakdown of morphology, primarily in nouns, in Polish aphasics was manifested by an incorrect distribution of inflectional suffixes reflected by substitution errors. Tomaszewska-Volovici found that, on the whole, the pattern of breakdown did not diI3er q~~~tively between fluent and nonfluent aphasics, and that the difference was primarily quantitative. The author did not find any specific patterns in disturbance of particular suffixes apart from vulnerability of noun stems which undergo morphophonemic alterations. PURPOSE OF THE STUDY Several research questions were posed in this study. At the most general level they all dealt with the characterization of the nature of disruption of morphology in a Wernicke’s patient, who was a speaker of a richly inflected language, Polish. The specific questions addressed were the following:
80
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Neurobgubti,
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l(1988)
1. Are there any differences in the disruption of morphological systems of inflectional structures as opposed to de~vational structures? 2. Are there any differences in the disruption of morphology of particular word classes such as nouns, verbs, and adjectives? 3. Are there any differences in disruption of particular inflectional categories within one word class (for example, aspect vs tense, category in verbs)? 4. Is there a difference in the amount of disruption of mo~hology depending on the type of linguistic context it is embedded in, i.e. word, phrase, sentence, discourse? 5. Is there a difference in the amount of disruption of morphology depending on the type of task, i.e. on-line processing in real-time, s~ntaneously as opposed to off-line tasks of me~ling~stic nature such as constructing sentences with given words? CASE HISTORY The patient in this study was a 39 year old female with a degree in psychology who suffered for a number of years from high blood pressure which was untreated. On January 30, 1983 she experienced an acute headache and lost consciousness. She was taken to a hospital where angiography was performed. The angiogram revealed an aneurysm in the left middle cerebral artery located just before the trifurcation. It was narrow, 8 mm in length. There was a slight shrinkage of the artery. The patient was operated on and the aneurysm was clipped. Four years after the surgery a CT scan was performed. It showed a hypodensive focus of irregular shape 46 x 28 mm in size. It was located at the base of the left temporal lobe and was consistent with softening of the tissue of the original lesion. Postoperatively, she presented with severe fluent aphasia. The patient was sent to a rehabilitation institute where she received speech therapy. She was first seen by us seven months after the surgery. Since that time she has been undergoing speech therapy. Her communicative competence has improved, although specific language deficits remained. Over a year ago she resumed part-time work as a salesperson in a clothing store. NE~OLINGUIS~C
PROFLLE
Observations and examinations of the patient which form the basis of this investigation cover the period of four years post-onset. The diagnostic tests administered to the patient at the beginning of the rehabilitation and four years later provided information as to the type and severity level of aphasia. (See Appendix.)
FeatureaofAgrammatlaninPoUah
81
A diagnosis was made of acoustic-mnestic aphasia according to Luria’s classifications and aphasia of Wemicke type with moderate severity level (3) according to the Severity Scale of the Boston Diagnostic Aphasia Examination. According to Luria, the most conspicuous deficit resulting from this aphasia is pathologically increased inhibition of auditory verbal traces. The patient exhibited difficulties in repeating phonologically complex words and sequences of words, especially those that were semantically unrelated or syntactically complex as well as larger complex phrases and sentences. The patient experienced word finding difficulties. She produced literal and verbal paraphasias in all modalities (i.e. in speech, reading, writing and also in repetition). The number of errors in reading and writing was smaller than in oral language and repetition. Finally, there was no difficulty in differentiating minimal phonemic pairs or phonetically similar words, and in comprehension of simple grammatical constructions. The data for the investigation were collected from a variety of tasks which required producing sentences and connected texts, in spoken and written form. Tasks involving sentences were constructed in such a way that they required manipulation of various inflectional forms. Production of texts involved telling or retelling stories read by the examiner. The spoken data were tape recorded and transcribed for analysis. Analysis of these data enabled us to understand why this patient, with her particular deficits, was communicatively viable and was making steady progress in her recovery. It was found that the patient exhibited a relatively well preserved lexicon as well as a basic set of syntactic structures which enabled her to build sentences. She also preserved the ability to utilize the lexical and syntactic resources in order to build connected texts. The patient exhibited good judgment of grammaticality of both her own speech and, to a greater extent, other person’s speech. This ability helped her to understand her strengths and her weaknesses and, to some extent, correct her mistakes. All of the above features were noted in her speech and writing, the latter being the less impaired modality. The most dramatic impairment was manifested in the area of morphology of all inflectional forms, i.e. nouns, adjectives, numerals, and verbs. This type of impairment has been the focus of much of the recent research on agrammatism in aphasia. The data obtained from this patient allowed us to consider some of the issues of agrammatism, especially pertaining to the relationship between the impairment of morphology as opposed to syntax. AGRAMMATISM
This section will consist of a general description of the patient’s agrammatism, followed by a more detailed description of disruption of morphology. NIL 3:1-F
Agrammatism of the patient was characterized by two dissociations. The first dissociation occurred between inflectional and derivational morphology in that there was an impairment of all inflectional categories, i.e. of nouns, verbs, and adjectives, with relative preservation of derivational morphology. There was also a di~~iation between impai~ent of infl~tional mo~holo~ and preservation of the order of morphological and syntactic elements. The impairment of inflectional morphology was manifested by incorrect distribution of suIIixes and not by their reduction. There was no regularity of pattern in substitution of one &ix by another, although not all the suEixes were equally disturbed. The s&ix marking nominative case in singular and the suffix marking third person present tense and infinitive were the least impaired. Substitution errors did not cross word categories, e.g. noun suffixes were attached to nouns, and verb suffixes to verbs. However, substitutions within the subclasses did occur. Within the inflectional categories, verb inflections constituted the most frequently disturbed category. Both verb sufhxes marking person, gender, tense and aspect, and prefixes addition~ly marking aspect were disturbed. Particles which mark reflexive verbs, and participle forms were greatly reduced. Word stems which undergo morphophonemic alternations were particularly vulnerable to disruption. Impairment of morphology occurred in both spoken and written language. There was a considerable variability of performance reflected by the differences in the number and type of substitution errors depending on modality, type of task, and time needed to perform the task. The number of errors increased when the same task was spoken as opposed to written, or when less time was given for planning as in spontaneous as opposed to rehearsed speech, or when the conceptual complexity of the task was higher, for example, in an expository discourse on a given topic as opposed to retelling a simple narrative. Finally, there was a considerable increase of errors in sentences used in isolation as opposed to connected discourse. Derivational MorphoIogy
Derivational mo~holo~ was investigated both in nouns and verbs. The tests were performed in the first year post-onset and four years later. Four different categories of nouns were included: agentive nouns in masculine gender, agentive nouns in feminine gender, diminutive nouns and locative nouns. The forms were elicited with a set of questions, the examples of which are included below. Derivations1 Form Agentive Noun, Masculine Agentive Noun, Feminine
FeatmmofAgramnutimiiPolbb
83
Diminutive Noun Locative Noun Sample Questions What What What What Form
do do do do as
you you you you
call someone who writes? call a clerk who is a woman? call a little gower? call a place where one skates? many nouns as possible with the ending -arnia (a locative SUI%X).
Additionally, a set of correct and incorrect diminutive forms was presented in a judgment of grammaticality task. The results of the study revealed that on the whole, derivational morphology was preserved in this patient. Occasional errors were found in agentive nouns where a correct suffix was added but the noun stem did not show a morphophonemic alternation of palatalization, e.g. gazet’-& gaze& (newspaper boy): vind’u% vind& (elevator boy). It should be noted that formation of many agentive nouns involves two processes: adding a s&ix and changing the stem. No errors were found on the test of agentive nouns in the feminine gender. Diminutive nouns were 82% correct at the beginning of the study and 85% correct at the time of testing four years later. Judgment of grammaticality of diminutive nouns was 100% correct. The errors in diminutive nouns consisted of substitution of marked allomorphs by unmarked ones, e.g. tale&R tale&& Locative nouns did not produce any errors. No substitution of derivational sufhxes by inflectional suffixes was observed. In verbs, derivational morphology was investigated in prefixal system marking perfective and imperfective aspects. Prefixed verbs were tested in isolation and in sentence and text contexts. Additionally, judgment of grammaticality tests of prefixed verbs were administered. Error analysis of these verb forms showed a number of errors in the derivation of prefixes marking aspect, e.g. o-si’ivaw z-s’ivaw (got grey). Most of the errors consisted of substitutions within the set of possible verbal prefixes (95%). No notable improvememt was observed in performance with respect to derivational morphology over the four years of study. Idktlond
Moqbology
Production of two main inflectional categories, i.e. nouns and verbs, was investigated. Noun and verb sufbxes were elicited in contexts of varying size, i.e. word, phrase, sentence, and text, with the target nouns and verbs given in canonical form, i.e. nominative case in nouns and infinitive form in verbs.
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Journalof Neurolinguistica, Volime 3, Number l(1988) Noun
Morphology
All noun errors consisted of in-class substitutions of suffixes. Testing of nouns in paradigms revealed that various case suffixes were differentially impaired with the genitive case being least impaired (33%) and the dative case being most impaired (50%). On testing four years later, the overall impairment of all &Fixes was still the same (39% errors), but the distribution of errors in particular cases was more balanced. Errors in mo~hophon~i~ alternations in noun stems were frequent and persisted. No difference was found in performance on noun suffixes in different genders. There was considerable difference in performance on noun suffixes between spoken and written discourse on the initial testing, when only 32% of suffixes were correct in spoken discourse, but 82% were correct in written discourse. Four years later this difference in performance disappeared, with 93% correct suffixes in spoken texts and 91% in written discourse. Verb Morphology
Verbs tested in paradigms for person, gender and tense revealed only 12% correct suffixes. Errors consisted of substitutions of sufhxes within verb category. Substitutions involved all categories, i.e. person, tense and gender. In tasks involving use of verbs in sentences, errors consisted primarily of use of masculine gender instead of mixed gender in past tense. There was a variability of performance on those gender suffixes on tests given within a period of several months, with number of errors varying from 30% to 0%. Performance on aspect in verbs was also considerably impaired. Substitution of aspect suffixes did not reveal any direction between perfective and imperfective aspect. Only slight improvement was noticed on aspect performance on the initial testing and on testing four years later (40% vs 35% errors). In discourse, the performance on verbs indicated the same tendency as on nouns in that only 28% of suffixes were correct in spoken discourse as compare to 80% in written discourse. This considerable difference disappeared four years later when the correct suffixes in spoken discourse increased to 86% and decreased only slightly in written discourse to 78%. Compr~~
of In~tio~
Suffixes
Comprehension of inflectional suffixes of nouns was tested in sentences. The sentences were constructed in such a way that their meaning could be decoded only if the function of a given noun stix was known. All sentences departed from SVO canonical order. The tasks used to test comprehension of infl~tional saxes consisted of transfo~ng the target sentence into canonical
word order, and of performing an action according to the target sentence command. The results indicated a considerable improv~~t across time on the latter test, with only 23% correct responses on the initial testing and 100% on the testing performed four years later. Performance on the other test mentioned above showed 89% correct responses on the second testing as compared to 57% on the initial testing.
syntax In order to better understand the agrammatism of this patient, a brief description of her syntactic performance will be given below. Syntax was explored both in isolated sentences and in texts. The word order in both phrases and sentences was preserved. Most of the sentences exhibited canonical SVO order (82%). There was, however, a reduction of sentential complexity as exhibited by a smaller number of embedded clauses, which was especially noticeable when the patient’s stimulus retellings were compared to the original stimulus texts. However, the clausal length was not significantly different. Dependent clauses consisted primarily of noun clauses and relative clauses, the most frequent clause types. ~onfinite participal clauses were not used at all. Reduction of clausal complexity as manifested also by use of verbless clauses or clause equivalents. There was also some reduction of complexity of modification structure at the phrasal level. The primary effect of disruption of inflectional morphology was exhibited in impairment of syntactic relations of agreement and government where the two levels of mo~holo~ and syntax cross. The study of the use of function words showed that omission of function words was very infrequent. When found, it involved primarily the omission of reflexive particles when preceded by a verb and occasionally omission of prepositions and connectors. Other errors in function words involved substitution within the class of prepositions and within the class of connectors.
Morphology is an important but poorly understood device for producing cohesion in texts. The identifi~tion of rno~holo~~ suffixes on nouns helps to indicate the roles of participants and the relationships among them in narrative texts, while the identification of suflixes marking tense and aspect on verbs helps to trace discontinuities in action and foregrounding of important events. These morphological sufhxes are especially important in more complex texts. The question which was addressed in this research was the relationship between disrupted morphology and the quality of the text. The most important finding
86
Journalof Newolinguistks, Volmw 3, Number1 (l!MB)
in this respect is that the disruption of morphology did not seriously affect the intelligibility and cohesion of the texts. When the patient’s texts were given to judges who had to reconstruct their meaning after listening to or reading the texts, they were able to do so. This was possible for the following reasons. The preservation of syntactic elements and the reduction of sentential complexity and sentential variety resulted in sentences of canonical SVO type. In these sentences no ambiguity occurred as to semantic interpretation of syntactic elements despite disruption of inflectional morphology. Preservation of order of elements within noun phrases and verb phrases allowed the identification of agreement and government relations on the basis of mere contiguity of elements despite the lack of morphological congruity. Discourse level analysis of the texts revealed preservation of macrostucture of texts in that reference structure and chronological sequence of events were maintained. This preserved macrostructure supported cohesion despite the disruption of morphology. Thus preservation of chronological sequence of events counteracted the disruption of tense-system morphology in verbs. SUMMARY AND CONCLUSIONS
This study reported on agrammatism in a fluent aphasic, which consisted of severe disruption of inflectional morphology with relative preservation of derivational morphology and word order. Agrammatism was exhibited at a number of linguistic levels. At the level of morphology it involved disruption of alternations of noun and verb stems and substitution of sufbxes within these categories. The findings of vulnerability of inflectional morphology and preservation of syntactic order of elements confirms the results of previous research on aphasia in inflectional languages (Tomaszewska-Volovici 1976; Bates and MacWhinney in press). It is not clear at this time to what extent the disruption of morphology is related to deficits at the phonological level, since most of the suffixes consist of one syllable and often of one phoneme unit, they may be perceptually difficult and ambiguous. It is important to note that the impairment of morphology was evident in both production and comprehension tasks and in both spoken and written language. Greater impairment of verb morphology as opposed to noun morphology is presumably related to the grammatical and semantic complexity of the morphological system in verbs. As far as the preservation of derivational morphology is concerned, it is possible that derivational suffixes are much more strongly attached to the noun stems than inflectional suffixes in oblique cases and are processed as unitary elements. This would also be consistent with the finding of better preservation of nominative case suffixes since they also might be processed as unitary
FertwesofAgmmmatimninPolM
87
elements. At the level of syntax, the disruption of inflectional morphology entailed errors in syntactic relationships of agreement and government. At the level of discourse, errors were especially evident in tense and aspect markings of the event line. Agrammatism in syntax was primarily exhibited in reduction of phrasal and sentential complexity of syntactic units as opposed to syntactic disruptions. Few errors in function words were observed apart from reduction in inventories of classes such as conjuctions. In the study of changes which occurred in the patient’s morphology in the process of recovery over time, there was a considerable recovery of morphology of all inflectional categories, nouns being the most recovered, verbs the least (when used in texts). There was a smaller improvement in isolated sentences. The pattern of substitution errors basically did not change, although there was some leveling of differences in number of errors across particular morphological forms. There was also a marked improvement of morphology in all tasks involving off-line processing, i.e. allowing for monitoring the output as opposed to on-line processing of spontaneous speech. It is important, however, that with all of the improvements in this patient’s morphology, the basic character and the nature of impairment did not change. Finally, the vulnerability of the patient’s performance on morphology depending on the task requirements, modality and time, all indicate that the mechanism of the impairment is that of interference and difficulty of access rather than loss of morphological information. This study relates to previous work on agrammatism and, more specifically, on the dissociation between morphology and syntax by confirming the vulnerability of morphology across a number of different languages, such as German, Italian and English in fluent and non-fluent aphasics (Bates et al. 1987). The study also confirms that word order is relatively well preserved in both fluent and non-fluent aphasias in various languages (Goodglass 1968; Bates et al. in press). In conclusion, we can only underscore the finding that morphology, because of its vulnerability, is an especially interesting domain of neurolinguistic research, since it allows us to understand better the nature of agrammatism in highly inflectional languages. We hope that this study is a step in that direction. REFERENCES
Bates, E., A. Friederici, and B. Wulfeck Morphology in Aphasia. 1987 “Grammatical Languages,” Cortex. 23, 545-574.
Evidence
from
Three
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Joumal of Neurolinguistks,Volume 3, Number 1(1!488)
1987
in Aphasia: A Cross-linguistic Study,” Brain and
“Comprehension
Language 32, 19-67.
Caplan, D. 1986 “Connections Clinical
Between Linguistics,
Aphasiology:
Conference
Neuroscience Proceedings,
and Aphasia,” pp. 14-23,
Minneapolis, MN: BRK Publishers Goodglass, H. 1968 “Studies on the Grammar of Aphasics,” in Developments in Applied Psycholinguistics Research, S. Rosenberg and J. Kaplin (eds.), New York: Macmillan Co. MacWhinney, B. and E. Bates Cross-linguistic Studies of Language Processing, New York: Cambridge University Press, in press. Menn, L. and L.K. Obler (eds.) 1988 Agrammatic Aphasia: Cross-language Narrative Sourcebook, Amsterdam: John Benjamin, in press. Tomaszewska-Volovici, H. 1976 Agrammatism in Aphasia, Wroclaw: Polish Academy of Sciences (in Polish).
APPENDIX Language Assessment
Function Assessed
Tests
Level of severity of aphasia Naming
Boston Diagnostic Aphasia Examination Boston Diagnostic Aphasia Examination Boston Naming Test Boston Diagnostic Aphasia Examination Token Test
Comprehension
Initial Testing
Second Testing (4 years later)
3
4
86%
98%
25% 82%
36% 99%
37%
93%
J. ~~f~z~, Volume 3, Number 1, pp. 7748.1988. Printed in Great Britain
Features of Agrammatism in Polish -ACmeStudy Hanna K. Ulatowska University of Texas at ~a~~~ Dallas
Maria Sadowska PO&~ Academy of Sciences and Medical School Warsaw
AB!STRACT Much l-ecentresearch in aphasia has been devoted to the characterimtion of the syndrome of agrammatism. At the same time, it has become increasingly clear that at least some aphasic syndromes and most notably agrammatism am deficits which am most precisely described along grammatical lines rather than according to the various linguistic activites such as comprehension, reading and writing. The realization that aphasic deficits are selective along grammatical lines has important consequences, since it provides us with an excellent op~~u~ty to bridge the gap between theories of language structure and aphasiology. The interest in agrammatism has in turn led to expanding the studies to languages representing different structural types in order to explore the effect of the specific structure on the disruption of language in aphasia. This article will deal with the issue of the selectivity of grammatical breakdown and the dissociation between various grammatical subcomponents in the language of a Polish agrammatic patient who has been studied longitudinally for the last three years. More specifically, the selectivity of the im~ent of the Sectional mo~holo~ with relative preservation of derivationa morphology will be discussed. A@ the dissociation between the preservation of syntactic order and impairment in syntactic agreement and government in the same aphasic patient are described.
INTRODUCTION
In studying the relationship between brain and language, most aphasiologists assume that the patterns of dissociation observed in different aphasic I syndromes represent decomposition of a universal language processing system. And yet, most contemporary research on aphasia has been carried out exclusively in English, resulting in a confounding between language-specific content and universal m~ha~sms. However, some recent work on crosslinguistic studies in aphasia (MacWhinney and Bates in press; Menn and Obler 1987) suggest more differentiation as a function of language type with few differences in the nature of grammatical breakdown among patients groups.
78
Joumal of Neurollnguirtics, Volume 3, Nlnnber l(l988)
These studies indicate that the “same” aphasic syndromes look very different from one language to another. In fact, language differences account for more variance than patient group differences. Another set of facts which emerges from these studies deals with the characterization of grammatical breakdown in aphasia, which provides strong evidence for a selectively greater impairment of grammatical inflections and function words than other aspects of language. This selective vulnerability of morphology is not restricted to agrammatics, but occurs in different patient groups. It is apparent that the vulnerability of morphology is especially evident in highly inflectional languages. However, despite this vulnerability of morphology, aphasic patients still seem to preserve a great deal of information about the “morphological shape” of their language. Also, although the contrast between agrammatism and paragrammatism seems useful in English where omission is the option most often elected by an agrammatic patient, the distinction breaks down in a richly inflected language where substitution is the most common type of error for both fluent and non-fluent aphasics. The most common substitution errors are within-class substitutions. Patients do not, for example, place verb inflections on a noun. Furthermore, within a broad class they rarely make substitutions between different subclasses. Although substitution and omission errors both occur, no evidence has been found to date for violations of morpheme order. The studies of sentence comprehension indicate that aphasic patients preserve control over morphology in comprehension that is proportional to the strength of morphology in their native language. At the same time, however, the closed class elements are selectively vulnerable to brain damage even in languages with a strong morphology. In general, the results of the studies of comprehension of morphology parallel the results for sentence production in every way, including the surprising lack of difference across patient groups (Bates et al. 1987, in press). Finally, the above studies indicate that the best way to characterize the breakdown of morphology is in terms of access rather than loss. That is, patients show an ability to retrieve and use morphological patterns correctly when there is enough redundancy in semantic-pragmatic functions or syntacticmorphological context. All of the above information indicates the need for further research focused specifically on morphology in a richly inflected language. The basic question which can be posed then is: what constraints does the “morphological shape” of a language place on the range of symptoms observed in fluent and nonfluent aphasia? In order to address some of the issues raised above, a single case study will be presented. As Caplan (1986) stated recently, “Single case analyses provide the
best opportunity for studying language pathology in detail and there is no replacement for detailed single case analysis if one’s goal is to document a particular deficit in an individual.” This study presents a Wemicke’s aphasic who is a native speaker of Polish, a richly in&&d language. The patient is capable of producing large amounts of language in both spoken and written modalities. The patient presents aphasia which is primarily characterized by breakdown of morphology. Since the patient exhibited a rich pattern of morphological breakdown, we decided to study her longitudinally. We feel that the vast data accumulated has revealed some facts to us about the nature of the breakdown of language and has allowed us to speculate about some generalizations to fluent aphasias in highly inIIectiona1 languages. Before proceeding to the description of the case, a brief characterization of the morphological system in the Polish language will be given. All inflectional word classes are marked by sufhxes which indicate the following categories: in nouns, gender, number, case, and d~lension; in adjectives, gender, number, and case; in verbs, number, person, gender, tense, and aspect. Additionally, aspect is marked on some verbs by prefixes. There is a rich system of derivational morphology which is marked by suflixes. Stems of inflectional and derivational forms undergo many morphophonemic changes. Inflectional forms function syntactically in structures of agreement and government. Agreement occurs between nouns and their modifying adjectives according to gender, number and case, and between subjects and their predicates in person and number, and in gender in some tenses. Government occurs between a governing word such as verb or preposition and the noun that follows marked by a given case. Up to now there has been only one published study dealing specifically with impairment of mo~holo~ in agr~matism in Polish ~orn~~ka-Volo~~ 1976). The results of the study showed that breakdown of morphology, primarily in nouns, in Polish aphasics was manifested by an incorrect distribution of inflectional suffixes reflected by substitution errors. Tomaszewska-Volovici found that, on the whole, the pattern of breakdown did not diI3er q~~~tively between fluent and nonfluent aphasics, and that the difference was primarily quantitative. The author did not find any specific patterns in disturbance of particular suffixes apart from vulnerability of noun stems which undergo morphophonemic alterations. PURPOSE OF THE STUDY Several research questions were posed in this study. At the most general level they all dealt with the characterization of the nature of disruption of morphology in a Wernicke’s patient, who was a speaker of a richly inflected language, Polish. The specific questions addressed were the following:
80
Journalof
Neurobgubti,
Voice
3, Nmber
l(1988)
1. Are there any differences in the disruption of morphological systems of inflectional structures as opposed to de~vational structures? 2. Are there any differences in the disruption of morphology of particular word classes such as nouns, verbs, and adjectives? 3. Are there any differences in disruption of particular inflectional categories within one word class (for example, aspect vs tense, category in verbs)? 4. Is there a difference in the amount of disruption of mo~hology depending on the type of linguistic context it is embedded in, i.e. word, phrase, sentence, discourse? 5. Is there a difference in the amount of disruption of morphology depending on the type of task, i.e. on-line processing in real-time, s~ntaneously as opposed to off-line tasks of me~ling~stic nature such as constructing sentences with given words? CASE HISTORY The patient in this study was a 39 year old female with a degree in psychology who suffered for a number of years from high blood pressure which was untreated. On January 30, 1983 she experienced an acute headache and lost consciousness. She was taken to a hospital where angiography was performed. The angiogram revealed an aneurysm in the left middle cerebral artery located just before the trifurcation. It was narrow, 8 mm in length. There was a slight shrinkage of the artery. The patient was operated on and the aneurysm was clipped. Four years after the surgery a CT scan was performed. It showed a hypodensive focus of irregular shape 46 x 28 mm in size. It was located at the base of the left temporal lobe and was consistent with softening of the tissue of the original lesion. Postoperatively, she presented with severe fluent aphasia. The patient was sent to a rehabilitation institute where she received speech therapy. She was first seen by us seven months after the surgery. Since that time she has been undergoing speech therapy. Her communicative competence has improved, although specific language deficits remained. Over a year ago she resumed part-time work as a salesperson in a clothing store. NE~OLINGUIS~C
PROFLLE
Observations and examinations of the patient which form the basis of this investigation cover the period of four years post-onset. The diagnostic tests administered to the patient at the beginning of the rehabilitation and four years later provided information as to the type and severity level of aphasia. (See Appendix.)
FeatureaofAgrammatlaninPoUah
81
A diagnosis was made of acoustic-mnestic aphasia according to Luria’s classifications and aphasia of Wemicke type with moderate severity level (3) according to the Severity Scale of the Boston Diagnostic Aphasia Examination. According to Luria, the most conspicuous deficit resulting from this aphasia is pathologically increased inhibition of auditory verbal traces. The patient exhibited difficulties in repeating phonologically complex words and sequences of words, especially those that were semantically unrelated or syntactically complex as well as larger complex phrases and sentences. The patient experienced word finding difficulties. She produced literal and verbal paraphasias in all modalities (i.e. in speech, reading, writing and also in repetition). The number of errors in reading and writing was smaller than in oral language and repetition. Finally, there was no difficulty in differentiating minimal phonemic pairs or phonetically similar words, and in comprehension of simple grammatical constructions. The data for the investigation were collected from a variety of tasks which required producing sentences and connected texts, in spoken and written form. Tasks involving sentences were constructed in such a way that they required manipulation of various inflectional forms. Production of texts involved telling or retelling stories read by the examiner. The spoken data were tape recorded and transcribed for analysis. Analysis of these data enabled us to understand why this patient, with her particular deficits, was communicatively viable and was making steady progress in her recovery. It was found that the patient exhibited a relatively well preserved lexicon as well as a basic set of syntactic structures which enabled her to build sentences. She also preserved the ability to utilize the lexical and syntactic resources in order to build connected texts. The patient exhibited good judgment of grammaticality of both her own speech and, to a greater extent, other person’s speech. This ability helped her to understand her strengths and her weaknesses and, to some extent, correct her mistakes. All of the above features were noted in her speech and writing, the latter being the less impaired modality. The most dramatic impairment was manifested in the area of morphology of all inflectional forms, i.e. nouns, adjectives, numerals, and verbs. This type of impairment has been the focus of much of the recent research on agrammatism in aphasia. The data obtained from this patient allowed us to consider some of the issues of agrammatism, especially pertaining to the relationship between the impairment of morphology as opposed to syntax. AGRAMMATISM
This section will consist of a general description of the patient’s agrammatism, followed by a more detailed description of disruption of morphology. NIL 3:1-F
Agrammatism of the patient was characterized by two dissociations. The first dissociation occurred between inflectional and derivational morphology in that there was an impairment of all inflectional categories, i.e. of nouns, verbs, and adjectives, with relative preservation of derivational morphology. There was also a di~~iation between impai~ent of infl~tional mo~holo~ and preservation of the order of morphological and syntactic elements. The impairment of inflectional morphology was manifested by incorrect distribution of suIIixes and not by their reduction. There was no regularity of pattern in substitution of one &ix by another, although not all the suEixes were equally disturbed. The s&ix marking nominative case in singular and the suffix marking third person present tense and infinitive were the least impaired. Substitution errors did not cross word categories, e.g. noun suffixes were attached to nouns, and verb suffixes to verbs. However, substitutions within the subclasses did occur. Within the inflectional categories, verb inflections constituted the most frequently disturbed category. Both verb sufhxes marking person, gender, tense and aspect, and prefixes addition~ly marking aspect were disturbed. Particles which mark reflexive verbs, and participle forms were greatly reduced. Word stems which undergo morphophonemic alternations were particularly vulnerable to disruption. Impairment of morphology occurred in both spoken and written language. There was a considerable variability of performance reflected by the differences in the number and type of substitution errors depending on modality, type of task, and time needed to perform the task. The number of errors increased when the same task was spoken as opposed to written, or when less time was given for planning as in spontaneous as opposed to rehearsed speech, or when the conceptual complexity of the task was higher, for example, in an expository discourse on a given topic as opposed to retelling a simple narrative. Finally, there was a considerable increase of errors in sentences used in isolation as opposed to connected discourse. Derivational MorphoIogy
Derivational mo~holo~ was investigated both in nouns and verbs. The tests were performed in the first year post-onset and four years later. Four different categories of nouns were included: agentive nouns in masculine gender, agentive nouns in feminine gender, diminutive nouns and locative nouns. The forms were elicited with a set of questions, the examples of which are included below. Derivations1 Form Agentive Noun, Masculine Agentive Noun, Feminine
FeatmmofAgramnutimiiPolbb
83
Diminutive Noun Locative Noun Sample Questions What What What What Form
do do do do as
you you you you
call someone who writes? call a clerk who is a woman? call a little gower? call a place where one skates? many nouns as possible with the ending -arnia (a locative SUI%X).
Additionally, a set of correct and incorrect diminutive forms was presented in a judgment of grammaticality task. The results of the study revealed that on the whole, derivational morphology was preserved in this patient. Occasional errors were found in agentive nouns where a correct suffix was added but the noun stem did not show a morphophonemic alternation of palatalization, e.g. gazet’-& gaze& (newspaper boy): vind’u% vind& (elevator boy). It should be noted that formation of many agentive nouns involves two processes: adding a s&ix and changing the stem. No errors were found on the test of agentive nouns in the feminine gender. Diminutive nouns were 82% correct at the beginning of the study and 85% correct at the time of testing four years later. Judgment of grammaticality of diminutive nouns was 100% correct. The errors in diminutive nouns consisted of substitution of marked allomorphs by unmarked ones, e.g. tale&R tale&& Locative nouns did not produce any errors. No substitution of derivational sufhxes by inflectional suffixes was observed. In verbs, derivational morphology was investigated in prefixal system marking perfective and imperfective aspects. Prefixed verbs were tested in isolation and in sentence and text contexts. Additionally, judgment of grammaticality tests of prefixed verbs were administered. Error analysis of these verb forms showed a number of errors in the derivation of prefixes marking aspect, e.g. o-si’ivaw z-s’ivaw (got grey). Most of the errors consisted of substitutions within the set of possible verbal prefixes (95%). No notable improvememt was observed in performance with respect to derivational morphology over the four years of study. Idktlond
Moqbology
Production of two main inflectional categories, i.e. nouns and verbs, was investigated. Noun and verb sufbxes were elicited in contexts of varying size, i.e. word, phrase, sentence, and text, with the target nouns and verbs given in canonical form, i.e. nominative case in nouns and infinitive form in verbs.
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Journalof Neurolinguistica, Volime 3, Number l(1988) Noun
Morphology
All noun errors consisted of in-class substitutions of suffixes. Testing of nouns in paradigms revealed that various case suffixes were differentially impaired with the genitive case being least impaired (33%) and the dative case being most impaired (50%). On testing four years later, the overall impairment of all &Fixes was still the same (39% errors), but the distribution of errors in particular cases was more balanced. Errors in mo~hophon~i~ alternations in noun stems were frequent and persisted. No difference was found in performance on noun suffixes in different genders. There was considerable difference in performance on noun suffixes between spoken and written discourse on the initial testing, when only 32% of suffixes were correct in spoken discourse, but 82% were correct in written discourse. Four years later this difference in performance disappeared, with 93% correct suffixes in spoken texts and 91% in written discourse. Verb Morphology
Verbs tested in paradigms for person, gender and tense revealed only 12% correct suffixes. Errors consisted of substitutions of sufhxes within verb category. Substitutions involved all categories, i.e. person, tense and gender. In tasks involving use of verbs in sentences, errors consisted primarily of use of masculine gender instead of mixed gender in past tense. There was a variability of performance on those gender suffixes on tests given within a period of several months, with number of errors varying from 30% to 0%. Performance on aspect in verbs was also considerably impaired. Substitution of aspect suffixes did not reveal any direction between perfective and imperfective aspect. Only slight improvement was noticed on aspect performance on the initial testing and on testing four years later (40% vs 35% errors). In discourse, the performance on verbs indicated the same tendency as on nouns in that only 28% of suffixes were correct in spoken discourse as compare to 80% in written discourse. This considerable difference disappeared four years later when the correct suffixes in spoken discourse increased to 86% and decreased only slightly in written discourse to 78%. Compr~~
of In~tio~
Suffixes
Comprehension of inflectional suffixes of nouns was tested in sentences. The sentences were constructed in such a way that their meaning could be decoded only if the function of a given noun stix was known. All sentences departed from SVO canonical order. The tasks used to test comprehension of infl~tional saxes consisted of transfo~ng the target sentence into canonical
word order, and of performing an action according to the target sentence command. The results indicated a considerable improv~~t across time on the latter test, with only 23% correct responses on the initial testing and 100% on the testing performed four years later. Performance on the other test mentioned above showed 89% correct responses on the second testing as compared to 57% on the initial testing.
syntax In order to better understand the agrammatism of this patient, a brief description of her syntactic performance will be given below. Syntax was explored both in isolated sentences and in texts. The word order in both phrases and sentences was preserved. Most of the sentences exhibited canonical SVO order (82%). There was, however, a reduction of sentential complexity as exhibited by a smaller number of embedded clauses, which was especially noticeable when the patient’s stimulus retellings were compared to the original stimulus texts. However, the clausal length was not significantly different. Dependent clauses consisted primarily of noun clauses and relative clauses, the most frequent clause types. ~onfinite participal clauses were not used at all. Reduction of clausal complexity as manifested also by use of verbless clauses or clause equivalents. There was also some reduction of complexity of modification structure at the phrasal level. The primary effect of disruption of inflectional morphology was exhibited in impairment of syntactic relations of agreement and government where the two levels of mo~holo~ and syntax cross. The study of the use of function words showed that omission of function words was very infrequent. When found, it involved primarily the omission of reflexive particles when preceded by a verb and occasionally omission of prepositions and connectors. Other errors in function words involved substitution within the class of prepositions and within the class of connectors.
Morphology is an important but poorly understood device for producing cohesion in texts. The identifi~tion of rno~holo~~ suffixes on nouns helps to indicate the roles of participants and the relationships among them in narrative texts, while the identification of suflixes marking tense and aspect on verbs helps to trace discontinuities in action and foregrounding of important events. These morphological sufhxes are especially important in more complex texts. The question which was addressed in this research was the relationship between disrupted morphology and the quality of the text. The most important finding
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Journalof Newolinguistks, Volmw 3, Number1 (l!MB)
in this respect is that the disruption of morphology did not seriously affect the intelligibility and cohesion of the texts. When the patient’s texts were given to judges who had to reconstruct their meaning after listening to or reading the texts, they were able to do so. This was possible for the following reasons. The preservation of syntactic elements and the reduction of sentential complexity and sentential variety resulted in sentences of canonical SVO type. In these sentences no ambiguity occurred as to semantic interpretation of syntactic elements despite disruption of inflectional morphology. Preservation of order of elements within noun phrases and verb phrases allowed the identification of agreement and government relations on the basis of mere contiguity of elements despite the lack of morphological congruity. Discourse level analysis of the texts revealed preservation of macrostucture of texts in that reference structure and chronological sequence of events were maintained. This preserved macrostructure supported cohesion despite the disruption of morphology. Thus preservation of chronological sequence of events counteracted the disruption of tense-system morphology in verbs. SUMMARY AND CONCLUSIONS
This study reported on agrammatism in a fluent aphasic, which consisted of severe disruption of inflectional morphology with relative preservation of derivational morphology and word order. Agrammatism was exhibited at a number of linguistic levels. At the level of morphology it involved disruption of alternations of noun and verb stems and substitution of sufbxes within these categories. The findings of vulnerability of inflectional morphology and preservation of syntactic order of elements confirms the results of previous research on aphasia in inflectional languages (Tomaszewska-Volovici 1976; Bates and MacWhinney in press). It is not clear at this time to what extent the disruption of morphology is related to deficits at the phonological level, since most of the suffixes consist of one syllable and often of one phoneme unit, they may be perceptually difficult and ambiguous. It is important to note that the impairment of morphology was evident in both production and comprehension tasks and in both spoken and written language. Greater impairment of verb morphology as opposed to noun morphology is presumably related to the grammatical and semantic complexity of the morphological system in verbs. As far as the preservation of derivational morphology is concerned, it is possible that derivational suffixes are much more strongly attached to the noun stems than inflectional suffixes in oblique cases and are processed as unitary elements. This would also be consistent with the finding of better preservation of nominative case suffixes since they also might be processed as unitary
FertwesofAgmmmatimninPolM
87
elements. At the level of syntax, the disruption of inflectional morphology entailed errors in syntactic relationships of agreement and government. At the level of discourse, errors were especially evident in tense and aspect markings of the event line. Agrammatism in syntax was primarily exhibited in reduction of phrasal and sentential complexity of syntactic units as opposed to syntactic disruptions. Few errors in function words were observed apart from reduction in inventories of classes such as conjuctions. In the study of changes which occurred in the patient’s morphology in the process of recovery over time, there was a considerable recovery of morphology of all inflectional categories, nouns being the most recovered, verbs the least (when used in texts). There was a smaller improvement in isolated sentences. The pattern of substitution errors basically did not change, although there was some leveling of differences in number of errors across particular morphological forms. There was also a marked improvement of morphology in all tasks involving off-line processing, i.e. allowing for monitoring the output as opposed to on-line processing of spontaneous speech. It is important, however, that with all of the improvements in this patient’s morphology, the basic character and the nature of impairment did not change. Finally, the vulnerability of the patient’s performance on morphology depending on the task requirements, modality and time, all indicate that the mechanism of the impairment is that of interference and difficulty of access rather than loss of morphological information. This study relates to previous work on agrammatism and, more specifically, on the dissociation between morphology and syntax by confirming the vulnerability of morphology across a number of different languages, such as German, Italian and English in fluent and non-fluent aphasics (Bates et al. 1987). The study also confirms that word order is relatively well preserved in both fluent and non-fluent aphasias in various languages (Goodglass 1968; Bates et al. in press). In conclusion, we can only underscore the finding that morphology, because of its vulnerability, is an especially interesting domain of neurolinguistic research, since it allows us to understand better the nature of agrammatism in highly inflectional languages. We hope that this study is a step in that direction. REFERENCES
Bates, E., A. Friederici, and B. Wulfeck Morphology in Aphasia. 1987 “Grammatical Languages,” Cortex. 23, 545-574.
Evidence
from
Three
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Joumal of Neurolinguistks,Volume 3, Number 1(1!488)
1987
in Aphasia: A Cross-linguistic Study,” Brain and
“Comprehension
Language 32, 19-67.
Caplan, D. 1986 “Connections Clinical
Between Linguistics,
Aphasiology:
Conference
Neuroscience Proceedings,
and Aphasia,” pp. 14-23,
Minneapolis, MN: BRK Publishers Goodglass, H. 1968 “Studies on the Grammar of Aphasics,” in Developments in Applied Psycholinguistics Research, S. Rosenberg and J. Kaplin (eds.), New York: Macmillan Co. MacWhinney, B. and E. Bates Cross-linguistic Studies of Language Processing, New York: Cambridge University Press, in press. Menn, L. and L.K. Obler (eds.) 1988 Agrammatic Aphasia: Cross-language Narrative Sourcebook, Amsterdam: John Benjamin, in press. Tomaszewska-Volovici, H. 1976 Agrammatism in Aphasia, Wroclaw: Polish Academy of Sciences (in Polish).
APPENDIX Language Assessment
Function Assessed
Tests
Level of severity of aphasia Naming
Boston Diagnostic Aphasia Examination Boston Diagnostic Aphasia Examination Boston Naming Test Boston Diagnostic Aphasia Examination Token Test
Comprehension
Initial Testing
Second Testing (4 years later)
3
4
86%
98%
25% 82%
36% 99%
37%
93%