Phonological and neuroanatomical findings in three cases with apraxia of speech* Lesley Wolk MA (Speech Pathology) (Witwatersrand) Department of Speech Pathology and Audiology, University of the Witwatersrand, Johannesburg ABSTRACT This study investigated whether or not the articulatory errors on single consonants and initial consonant clusters in three adult aphasic patients with apraxia of speech could be characterized by underlying phonological processes. Naming tasks and spon- taneous narrative tasks were used for elicitation of speech samples. Computerized tomography was carried out in order to deter- mine possible neuroanatomical correlates of the linguistic findings in these cases. Results revealed that in each case, it was possible to trace underlying phonological processes which fit into strategy groups operationalizing particular phonetic prefer- ences. Similar trends occurred on all tasks. Self-employed strategies to aid phonological production were used by all cases during their struggle with successive attempts towards the target utterance. Neuroanatomical findings demonstrated brain le- sions which were more extensive than would be expected in the traditional concept of a focal lesion in Broca's area. In each case the left parietal region was involved. Theoretical and clinical implications are discussed. OPSOMMING Hierdie studie ondersoek die moontlikheid dat onderliggende fonologiese prosesse die artikulasie foute (enkel konsonante en inisiele konsonant kombinasie) van drie afasiepasiente met verbale apraksie kan karakteriseer word. Benoemingstake en spontane verhalende spraak is gebruik om spraakmonsters te ontlok. Gerekenariseerde tomografisie is onderneem om moontlik neu- roanatomiese korrelate van linguistiese bevindings in hierdie gevalle te bepaal. Resultate dui daarop dat dit in elke geval moont- lik was om onderliggende fonologiese prosesse uit te wys. Hierdie prosesse kon ingedeel word in groepe wat spesifieke fonetiese voorkeur verleen t.o.v. strategic soortgelyke neigings het in al die take voorgekom. Selftoegepaste strategies om fonologiese produksie te bevorder, is deur alle pasiente gebruik tydens hulle worsteling met opeenvolgende pogings tot die teiken uiting. Neumanatomise bevindings het getoon dat brein letsels groter was as wat verwag word van die tradisionele konsep van 'nfokaleletsel van Broca se area. In elkepasient was die linkse parietale area betrokke by die letsel. Teoretiese en kliniese implikasies is bespreek. ι Controversy has further ensued regarding the nature of articula- tory impairment. Some investigators have argued that articu- lation errors are random and unrelated to the target sound (Critchley, 1952; Deal and Darley, 1972) while others have con- cluded that errors are systematic and rule-governed (Blumstein, 1973; Martin and Rigrodsky, 1974a; 1974b; Klich, Ireland and Weidner, 1979). The development of apparent incompatible conceptions of the disorder is due, at least in part, to the phenomenon itself. In addition, guidelines for treatment have been somewhat fragmentary and meagre. Numerous workers in the field of adult apraxic disorders have extrapolated from child language in an attempt to unravel some of the conceptual controversies discussed and to design effec- tive treatment programmes. There may be several! imitations of this procedure, for example that of over-simplifying the adult aphasic breakdown. Yet, the knowledge acquired through ex- trapolating from child language has contributed in some way * This study formed part of the author's MA dissertation entitled "Phonological Impairment in Aphasia" submitted to the Department of Speech Pathology and Audiology, University of the Witwatersrand, Johannesburg. The South African Journal of Communication Disorders, Vol. 31 1984 @ SASHA 1984 Recent research into the area of aphasia has witnessed a surge of interest in articulatory disturbances, particularly in Broca's aphasic patients. Multiple terms have been employed to de- scribe the articulatory impairment; for consistency in this paper, the term 'apraxia of speech' will be used. The investigation of apraxia of speech in this study extracts from linguistic ap- proaches and neurological methods of investigation. Apraxia of speech is both controversial and complex despite many years of research. Several investigators have described the disorder as a motor programming disturbance not primar- ily due to neuromuscular or higher language functioning deficits, and have suggested that the programming of phonemes can be selectively impaired without impairment of language (Deal and Darley, 1972). Martin (1974), however, objected to the term 'apraxia of speech' and argued that motor program- ming disturbances are inextricably tied to language deficits and cannot be defined except within the framework of aphasia. R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) Phonological and Neuroanatomical Findings in Three Cases with Apraxia of Speech 37 to the understanding of these cases and to the overall clinical management. Research on distinctive feature analyses in pa- tients with apraxia of speech suggests that error productions are systematically related to their target sounds in terms of a feature breakdown (Martin and Rigrodsky, 1974a; 1974b). There has been limited application of phonological process analyses (Bowman, 1982). Phonological processes, as they are described in child language, refer to general simplifying processes that affect entire classes of sounds (Ingram, 1976). They do not reflect random errors, rather they are said to result from a set of systematic strategies operationalizing a child's phonetic preferences (Ingram, 1976; 1981). It has been argued that the phonological processes may provide the general patterns that need to be eliminated in therapy, and that if trained on key sounds, generalization is likely to occur (Weiner, 1979). Cohen, Gelfer and Sweet (1980) feel that it is essential for the clinician to evaluate the aphasic patient's speech performance and to compare this with the anatomical localization afforded by computerized tomography (CT). Buckingham (1979) fur- ther argues that it is difficult to determine what constitutes an apraxia of speech without further specifying the location of the lesion and the stimulus conditions which evoked the beha- viour said to be apraxic. Thus the primary goal of this study was to investigate whether the articulatory errors on single consonants and initial con- sonant clusters in three adult aphasic patients with apraxia of speech could be characterized by underlying phonological processes, considering which ones operate most commonly; a secondary goal was to describe CT scan findings in these cases. These findings are discussed briefly in a recent report (Wolk, 1982a). METHOD SUBJECTS Three adult male aphasic patients were used as subjects for this study. All cases were chosen from Johannesburg hospi- tals and were diagnosed as aphasic by neurologists and speech pathologists. They ranged from age 58 to 73 years with a mean age of 63,3 years. All cases presented a history of left (L) hemi- sphere cerebrovascular accident (CVA). They demonstrated various degree of concomitant Broca's aphasia. In each case, however, phonological deficit predominated. They ranged in months post onset (MPO) from 9 to 24, with a mean of 15,7 months. All cases were native speakers of English and had no previous history of speech or hearing problems, premorbid psy- chological problems, senility or mental retardation. Years of education ranged from 8 to 11 with a mean of 9,7 years. Case 1 had the most severe form of apraxia of speech, and Case 3 the least severe disorder. Subjects had to have suffered a left (L) cerebral infarct, and were required to have reached a point Table 1 Description of cases Age Sex Aetiology Months Post Onset MPO Type of Aphasia Home Language Educational Level Premorbid Occupation Handed- ness Speech Therapy Received Case 1 (A.M.) 58 Male CVA 24 Broca English Std. 6 Plumber (R) 18 months Case 2 (FT:) 73 Male CVA θ Broca English Std. 8 Despatch Manager (R) 4 months / /Case 3 (E.J.) 59 Ma e CVA 14 Broca English Std. 9 Salesman (R) 12 months Table 2 Results of Preliminary Tests ! / Preliminary Test Case 1 (A.M.) Case 2 (F.T.) Case 3 (E.J.) Boston Diagnostic Aphasia Examination (BDAE) Goodglass and Kaplan (1972) Score on severity rating scale = 2 Score on severity rating scale = 2 Score on severity rating scale = 2 Token Test De Renzi and Faglioni (1978) 34/36 = 940/0 34/36 = 94o/0 3 6 / 3 6 = 100% Oral Non-verbal Gesture Battery Moore, Rosenbek & La Pointe (1976) 56/56 = 100% 56/56 = 100% 56/56 = 100% Screening Pure-Tone Audiometric Test Normal Normal except 45dB at 4000 Hz bilaterally Normal Goldman-Fristoe Test of Auditory Discrimination (Goldman, Fristoe and Woodcock, 1970) 100% 100% 100% Discrimination of CVC and CCVC words (designed by the writer) 100% 100% 100% Die Suid-Afrikaanse Tydskrif vir Kommunikasieafwykings, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) 38 Lesley Wolk of neurological stability considered as six months after the neu- rological insult (Sarno and Levita, 1971). The description of cases is summarized in Table 1. PROCEDURE Preliminary tests were carried out to determine whether the subjects satisfied the selection criteria. These are summarized in Table 2. Two approaches were used for elicitation of speech for linguistic analysis: — (1) Naming Tasks and (2) Spontaneous Narrative Tasks. 1. Naming tasks A test comprising two parts was developed by the writer for use in this study. Part I was designed to test single consonants in initial (I) and final (F) word position, and Part Π was designed to test initial consonant cluster sequences. Criteria for Selection of Words Part I of the articulatory test was composed of 89 items, care- fully selected to elicit all the consonants (C) in English in (I) and (F) word positions. An attempt was made to select items in which the desired consonant in (I) and (F) word position could be elicited simultaneously, thus maximally conserving the total number of picture stimuli required (for example, ini- tial Id/ is elicited by the picture words 'dog' and 'duck' at the same time that final Igl and /k/ are being elicited). Each con- sonant was elicited at least twice in (I) and (F) word position, ranging between two and four different phonemic contexts. The phonemic environment was varied with respect to both vowels and consonants in the immediate phonemic vicinity. Thus 81 words represented consonants in (I) position, and 70 words re- presented consonants in (F) position, while the total number of test items was equal to 89. Part Π of the articulatory test was composed of 99 items. Each (I) cluster of English was elicited in at least two stimulus words, ranging between two and four different phonemic contexts. Experimental Manipulation of Words Stimulus items were constrained by the following:' i) phonological rules governing the combination and sequenc- ing of phonemes in English; ii) words which could be pictori- ally represented, for the reason that imitation was to be deliberately avoided; iii) word length and syllable structure were considered - mono syllabic and disyllabic words were includ- ed, while multisyllabic words were excluded; iv) morpholog- ical endings were excluded when devising the list of single consonants in (F) position so as to elicit 'pure phonological constructions'. The entire articulatory test thus comprised 188 stimulus items (Part I = 89; Part II = 99). Each response was elicited twice, to provide an estimate of the subjects' consistency of produc- tion of the same sounds in identical environments. Thus both parts of the naming task, naming singletons (NS) and naming clusters (NC) were administered twice to all subjects. 2. Spontaneous narrative tasks These included an open-ended conversation, description of fifty pictures and constructing a story from six pictures depicting real-life scenes. ADMINISTRATION OF PHONOLOGICAL ASSESSMENT PROCEDURE All testing took place in a sound-treated room and was carried out by the writer during several 45-minute sessions. Subjects were tested individually. For the naming tasks, pictures were presented in a random ord- er, but attempts were made not to present two words with the same consonant or consonant cluster successively. Part I (NS) and Part II (NC) were administered twice over four sessions, following the same procedure. For the spontaneous tasks, each subject had to describe the fifty picture cards selected and to tell a story for each of the six picture cards chosen. Spontane- ous narrative tasks were administered once over three or four sessions. RESPONSE TRANSCRIPTION All responses were recorded on a high quality Revox Tape Recorder (Model 1132 Dolby version). Wherever possible on- site transcriptions were carried out by the writer, utilizing both visual cues and contextual information. Tape recordings were transcribed by the tester in broad phonetic transcriptions, and were used as a comparison with on-site transcriptions. A sec- ond transcription of all data was carried out using three tran- scribers who served as judges. Judges worked independently and then met jointly to resolve any discrepancies, discarding any instances in which no consensus could be reached, provid- ing maximum objectivity and accuracy of recorded data. PHONOLOGICAL PROCESS ANALYSIS The goal was to discover whether articulation errors of these subjects could be characterized by general processes, and if so, which phonological processes were operating for each case. All CVC and CCVC words with error productions were ana- lyzed in terms of one or more of the following broad categories as described by Weiner (1979): a) syllable structure processes, b) harmony processes and c) feature contrast processes. Wi- thin these categories, several specific phonological processes were selected from those described in child language (Ingram, 1976; 1981; Weiner, 1979). i It was possible that multiple processes could occur at the same time for a particular error utterance, in which case credit jwas given to as many processes as were operating for that utter- ance. In this way it was possible to determine the frequency of occurrence of each process and its probable resulting effect on intelligibility. The same procedure was carried out for both naming and spontaneous tasks for each case. ASSESSMENT PROCEDURE FOR NEUROLOGICAL INVESTIGATION Neuroanatomical investigations of the cases in this study in- cluded general neurological examinations carried out by the same neurologist, and computerized tomography (CT) scans for each case. CT scans were performed with contrast enhance- ment on the Elscint 905 system. CT scan pictures obtained from the assessment procedure for the cases of this study were in- terpreted by a radiologist and two independent neurologists in order to provide a measure of objectivity and reliability. The South African Journal of Communication Disorders, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) phonological and Neuroanatomical Findings in Three Cases with Apraxia of Speech 39 RESULTS AND DISCUSSION PHONOLOGICAL FINDINGS Tkble 3 represents a summary of the phonological processes operating for all cases. The findings indicate that in each case certain phonological processes occurred more frequently than others, and that these occurred in similar proportions on both naming and spontaneous tasks. The findings will be discussed below in terms of three broad categories, i.e. syllable struc- ture processes, harmony processes and feature contrast pro- cesses. Syllabi" Structure Processes The three most commonly used syllable structure processes for all cases, were deletion of final consonant, weak syllable deletion and cluster reduction. Cluster reduction was the most commonly operating phonological process on naming tasks for all cases. It was necessary to develop a subcategory of the cluster reduction process to indicate that it was possible for an error substitution to reflect an extraction of select features of one or more elements of the target segment which merge together to form a new segment. This was referred to as 'fea- ture merging'. Feature merging comprised a substantial num- ber of errors, for example in the case of A.M., 27,64% and 34,48% of cluster reduction errors were seen to occur on nam- ing and spontaneous tasks respectively. An example of feature merging is clearly illustrated in the error substitution /sp/ for the target segment /skw/ which occurred in Cases 1 and 3. Here it can be noted that Isl remains the same, /p/ retains the plo- sive quality of C2 but acquires the labial quality of C3 in the target segment. A review of the data indicated that there was a frequent col- lapse of 2-element and 3-element cluster segments into one element in all cases. In A.M.'s system, the sound preference or neutralization process (Weiner, 1979) was /(/ as in j/sl, |/sk, ]/spl, (r/skw. In F.T.'s system, there were two sound preferences, /]/ and If I as in J/skw, J/str, f/skw, f/spl, f/bl, f/gr, fr/skw, fl/spr. In E.J.'s system there were three sound preferences /(/, If I and Isl as in J/str, j/skw, f/)r, f/kw, s/0r, s/fr s/tw. Therefore the blade-palatal fricative / / was a favourite sound strategy in all cases, the labiodental fricative If I was common to F.T. and E.J., and the tip-alveolar fricative Isl was an additional favourite sound strategy in E.J.'s system. The processes of reduplication, cluster contraction and epenthesis were operating in all cases, although less commonly Table 3 A distribution of errors on CVC and CCVC words according to phonological processes NO. AND % OF ERRORS NAMING SPONTANEOUS PHONOLOGICAL PROCESS A.M. F.T. E.J. A.M. F.T. E.J. No % No % No % No % No % No % SYLLABLE 1. Deletion of final consonant STRUCTURE 2. Weak syllable deletion PROCESSES 3. Cluster reduction - feature merging 4. Reduplication 5. Cluster contraction 6. Epenthesis / - vowel / - consonant 49 5,94 32 3,88 123 14,93 (34)* (27,64) 1 0,12 6 0,73 24 2,39 (11) (45,83) (13) (54,17) 51 12,17 35 8,35 89 21,24 (14) (15,73) 7 1,67 0 , 0 10 2,39 (2) (20,00) (8) (80,00) 13 5,78 4 1,78 39 17,34 (8) (20,51) 1 0,44 1 0,44 6 2,67 (4) (66,66) (2) (33,33) 40 6,23 66 10,28 58 9,04 (20) (34,48) 4 0,62 2 0,31 24 3,74 (7) (29,17) (17) (70,83) 46 9,74 71 14,61 40 8,23 (7) (17,50) 4 0,82 3 0,62 7 1,44 (2) (28,57) (5) (71,43) 14 4,64 30 9,93 48 15,89 (3) (6,25) 1 0,33 5 1,66 9 2,98 (3) (33,33) (6) (66,66) I HARMONY 7. Assimilations PROCESSES a) Progressive (P.A.) b) Regressive (R.A.) Initial consonant devoicing Final consonant devoicing Prevocalic voicing Labial assimilation Alveolar assimilation Velar assimilation Nasal assimilation 8. Metathesis - feature metathesis 29 3,52 62 7,52 15 1,82 16 1,94 9 1,09 21 2,55 41 4,98 13 1,58 10 1,21 30 3,64 (13) (43,33) 18 4,30 28 6,68 4 0,96 13 3,10 13 3,10 6 1,43 30 7,16 2 0,47 2 0,47 11 2,63 (7) (63,64) 11 4,89 27 12,00 3 1,33 7 3,11 4 1,78 14 6,22 13 5,78 2 0,89 2 0,89 1 0,44 (0) (0) 22 3,43 50 7,79 10 1,56 4 0,62 7 1,09 21 3,27 36 5,61 3 0,46 9 1,40 16 2,49 (8) (50,80) 26 5,35 33 6,79 12 2,47 6 1,23 11 2,26 14 2,88 30 6,17 2 0,41 6 1,23 12 2,47 (9) (75,00) 13 4,31 29 9,60 8 2,65 2 0,66 3 0,99 4 1,33 31 10,27 2 0,66 2 0,66 6 1,99 (1) (16,67) FEATURE 9. Stopping : CONTRAST 10. Fronting , PROCESSES 11. Denasalization 12. Nasal Substitutions 13. Gliding ' 14. Velar Substitutions 15. Liquidation 16. Interchange of /I/ and III 17. Frication 18. Affricatian 19. Vocalization (weakening) 66 8,01 93 11,29 12 1,46 27 3,28 16 1,94 23 2,79 27 3,28 49 5,94 4 4,9 26 3,16 0 0 9 2,15 29 6,92 2 0,47 7 1,67 4 0,96 5 1,19 11 2,63 12 2,86 4 0,96 8 1,91 9 2,15 14 6,22 28 12,45 2 0,89 5 2,22 5 2,22 4 1,78 6 2,67 1 0,44 5 2,22 5 2,22 2 0,89 47 7,32 103 16,04 17 2,65 13 2,03 9 1,40 7 1,09 29 4;52 36 5,61 4 0,62 4 0,62 1 0,16 22 4,53 80 16,46 9 1,85 10 2,06 4 0,82 8 1,65 10 2,06 6 1,23 5 1,03 0 0 9 1,86 19 6,29 44 14,57 5 1,66 3 0,99 3 0,99 2 0,66 8 2,65 5 1,66 2 0,66 1 0,33 3 0,99 TOTAL I 824 100 419 100 225 100 642 100 486 100 302 100 * Those, numberscenclosedibetween brackets are sub-divisions of major categories and are therefore not included in the totals of each column. Die-Suid-Afrikaanse jyUikrifvir Kommunikasieafwykings, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) 40 Lesley Wolk than those processes discussed above. Reduplication reflects the patients' awareness of the number of syllables in a given word, though he may not have the ability to produce the varie- ty of syllables in sequence. For epenthesis in all cases, the in- sertion of a consonant was usually slightly more common than the insertion of a vowel for both tasks. An observation of the data showed that in vowel epenthesis, the vowel most commonly used in all cases was the mid schwa /a/, whilst in consonant epenthesis, A.M. used nasals, stops and liquids, F.T. and E.J. used nasals, stops, liquids and fricatives. Cluster contraction was used less commonly. An observation of the data showed that when it was employed however, it was more likely to result in a voiceless rather than a voiced affricate. The common use of cluster reduction in aphasic patients with apraxia of speech is well documented in the literature (Blum- stein, 1973). The interesting observation in the present study was the finding that when clusters were reduced the error seg- ment could reflect an extraction of select features of one or more of the target elements, a phenomenon referred to in this study as 'feature merging'. Feature merging occurred in each case, but was found to be most common in Case 1 (the most severe case), and least common in Case 3 (the least severe case). This would seem to imply a simultaneous processing (decod- ing and encoding) of features comprising different phonemes. Further evidence is provided by the observation noted during testing that in each case occasional error utterances seemed to reflect the simultaneous production of two elements of a cluster. The intrusive schwa comprised the major part of vowel epenthesis, a process commonly reported in previous reports (Klich et al., 1979). Blumstein (1973) observed epenthesis of schwa and stop consonants, and she feels that these errors are often motivated by the particular environment in which they occur. Harmony Processes Harmony processes were generally common in the system of these cases. Assimilations occurred more commonly than me- tatheses and in each case regressive assimilations (anticipato- ry errors) outnumbered progressive assimilations (post-positioning errors) on both naming and spontaneous tasks. For A.M. and E.J. regressive assimilation occurred twice as frequently as progressive assimilation, while the difference was slightly narrower for F.T. It may be observed in Table 3 that there was a striking predominance of alveolar assimilation on both tasks for all cases. There was a prevalence of alveolar and labial assimila- tion for A.M. and E.J. Velar and nasal assimilation occurred less commonly. Other assimilatory processes such as prevo- calic voicing, initial and final consonant devoicing occurred, though less commonly in all cases. Assimilations took place not only with respect to syllables, phonemes or distinctive fea- tures within the boundary of a word, but also to those across word boundaries. Most errors occurred within a word. Metathesis occurred commonly in A.M.'s system, less com- monly in F.T.'s system and was uncommon in E.J.'s system. A subcategory of metathesis was developed to indicate a rever- sal of individual features as opposed to reversal of an entire phoneme, which will be referred to as 'feature metathesis'. Fea- ture metathesis comprised a major part of the total number of errors reflecting metathesis in the cases of A.M. and F.T., while only one instance of feature metathesis was noted on spontane- ous tasks in the case of E.J. In F.T., for example, 63,64% and 75,00% of metathesis errors were seen to occur on naming and spontaneous tasks respectively. The general trend that regressive assimilation occurred more commonly than progressive assimilation and that metathesis was less predominant, is consistent with previous findings (Blumstein, 1973; Itoh, Sasanuma and Ushijima, 1979). By con- trast Sasanuma (1971) found metathesis to be more common than assimilation, but it is of interest to note that he found a similar occurrence of feature metathesis in his patients. The findings of feature metathesis contributes to the viewpoint dis- cussed above that these patients may have simultaneous process- ing (decoding and encoding) of features comprising different phonemes. According to Itoh et al. (1979), the coarticulatory phenomenon in aphasic patients, especially anticipatory coar- ticulation, can be regarded as some manifestation of cortical- ly generated motor programming. The analysis of data from a coarticulatory point of view thus seems to indicate that some 'future scanning' appears to be operating in these patients with apraxia of speech, so that for example, the articulatory gestures for the following segments are brought into the preceding seg- ments. Anticipations, perseverations and transpositions of speech sounds occur in normal speakers and have been referred to as 'slips of the tongue' (Fromkin, 1971). Feature Contrast Processes Several processes governing the substitution of one sound for another were operating in each case. It may be observed in Table 3 that fronting and stopping were clearly the two feature contrast processes most commonly used, where fronting was more common than stopping. Fronting and stopping were pre- dominant for A.M. and E.J., yet fronting alone was most com- mon for F.T. Other processes operating for all cases were denasalization, nasal substitutions, velar substitutions, liqui- dation, interchange of /]/ and /r/, frication, affrication, vocali- zation and gliding. A review of the data showed that in the process of gliding, the substitution of /w/ was generally more common than /j/ in all cases. i These findings are consistent with previous research (Critch- ley, 1952; Blumstein, 1973). Specifically, the prevalence of stop- ping, in patients with apraxia of speech, has beein highlighted (Klich et al., 1979). In support of the universality of language dissolution, Peuser and Fittschen (1977) found some similar phonological processes, such as stopping and denasalization, to be operating in a case of a Turkish aphasic, and thus feel that "Phenomic disorders due to aphasia seem to have a regu- lar and universal character" (Peuser and Fittschen, 1977, p. 202). Thus in common with Blumstein (1973), it can be con- cluded that many of the error types found in these aphasic adults with apraxia of speech, do in fact reflect the natural phono- logical processes which operate in all languages. In this study the same phonological processes were seen to be operating for both singletons (CVC) and clusters (CCVC), providing evidence for the systematic jgovernment of articulation errors. Blumstein (1973) showed that phonological error patterns were systemat- ic within groups and were similar across groups of aphasic adults. It might be valuable to investigate further whether phonological errors in other aphasic types (with varied lesions) y The South African Journal of Communication Disorders, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) Phonological and Neuroanatomical Findings in Three Cases with Apraxia of Speech 41 could be characterized by similar natural phonological process- es as found for the Broca's aphasic cases of this study. The data in this study refer to the speech samples of three adult cases. They therefore clearly cannot form the basis for any ex- tensive comparison with the development of speech in chil- dren. However, the findings suggest that there are some differences between the phonological dissolution in these aprax- ic cases and phonological acquisition in the child, but that the general patterns in these adult cases resemble those used by children. The reader is referred to Wolk (1982b) for a further discussion. During the course of eliciting phonological data it became clear that all cases tended to employ a number of different strate- gies to aid phonological production. Self-employed strategies were used on naming and spontaneous narrative tasks in their struggle with successive attempts towards the target utterance. The following strategies will be discussed below: 1. Revisualization of the written word. 2. Use of Semantic Associations. 3. Silent Articulations. 4. Reduced speech rate. 1. Revisualization of the written word Case 1 (A.M.) and Case 2 (F.T.) were frequently able to evoke clear-cut mental images of the written words and could oper- ate with these mental images, while they were completely un- able to articulate them. A.M. could spell the appropriate letter(s) of a target word out aloud, although he could not produce them phonically, for example "y" for "yacht", "g" for "frog" and "c,q" for "squirrel". It may be noted that he arbitrarily selected a letter from the initial or final word posi- tion. Furthermore, he spelled out aloud the letters "s", "k", "y" for the word "sky", but could not articulate the word as a whole. He was often noted to recall the number of letters comprising a target word, such as "three letters" for "zoo". On one occasion A.M. was seen to perform the mechanical movements of writing with his J fingers in an attempt to spell the word, i.e. "x, y, ζ . . . zed" for "zoo". It thus appeared that he was mechanically converting sound sequences into graphic symbols. j F.T. was also noted to spell the words put aloud in order to facilitate articulatory production. The interesting feature not- ed in this case was that the articulatory error production often reflected a revisualization of the visual representation of the word (the graphic symbols) rather than the phonic representa- tion (the acoustic image). For example /I D t j . . . j Dtj/ and /I Dtj . . . t| D:/ were successive attempts at the target word "yacht". It can be observed here that the error utterances show possible signs of interference from F.T.'s visual associations with spell- ing pronunciation variants. The finding that these cases recall printed letters in order to aid articulatory production is con- sistent with previous literature (Nebes, 1975). 2. Use of Semantic Associations All cases were seen to employ a carrier phrase with semantic relevance in order to aid articulatory production. This tenden- cy was the most prominant in F.T. Table 4 provides an exam- ple from the data for F.T., illustrating how he uses several semantic associations in order to recall the target item 'zebra'. Here it can be seen that some basic features of the object to be named are distinguished. Buckingham and Rekart (1979) state that this necessitates a clear image of the object on the one hand, and a well-organized acoustic-phonologic structure of the appropriate name on the other. For further discussion, refer to Wolk (1982b). Table 4 An example of the use of semantic associations to recall the target item 'zebra' by F.T. Target Word Error utterances in the sequence as produced by C2 zebra /z ZlfVA ZfbA blfVA tAijki hD:s r . . . . straips/ 3. Silent Articulations It was observed during elicitation procedures that all cases used subvocal activity to aid articulatory production. This was in the form of continually moving articulatory structures grop- ing to find correct postures. On presentation of a stimulus item A.M. and E.J. were some- times noted to monitor themselves silently using covert artic- ulations prior to producing the word aloud. Similar behaviour was seen for F.T., although his covert articulations seemed to be combined with an audible whisper, and it was noted that for F.T. the labiodental fricative /f/ was commonly used dur- ing repeated trials of subvocal activity. An interesting obser- vation was that F.T. often achieved correct articulation during whispering but not with voicing. This would suggest that one of the manifestations of the difficulty in this case with apraxia of speech, might be the co-ordination between articulatory and phono-respiratory mechanisms. These findings are consistent with studies reported in the liter- ature pertaining to both normal subjects and cases with aprax- ia of speech (McGuigan, 1970; Warren, 1977). McGuigan (1970) demonstrated that in normal adults internal verbal processes (rehearsal) are usually accompanied by small, covert move- ments of the lips, tongue and larynx which may be referred to as 'implicit speech'. McGuigan (1970) further states that as the performance of a task becomes more automatized, both the amplitude and the frequency of occurrence of these move- ments tend to decrease, which led to the suggestion that covert oral activity plays an important role in language. Nebes (1975) in common with Warren (1977) contends that patients with apraxia of speech have relatively intact implicit speech pat- terns. For the cases in this study, it is interesting to note that the amplitude and frequency of covert articulatory movements were significantly less in E.J. than in A.M. and F.T., suggest- ing that in the more severe cases of this study, automaticity of the articulatory movements was more impaired. In an attempt to extrapolate from various proposals put for- ward by Nebes (1975), the following theoretical possibilities can be considered: (a) Whether covert oral activity in these cases may in feet fecili- tate processing of articulatory images in the presence of possible auditory feedback disturbance, and Die Suid-Afrikaanse Tydskrif vir Kommunikasieafwykings, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) 42 Lesley Wolk (b) It may be that proprioceptive/kinaesthetic feedback from the muscles of articulation, which in these cases was felt to be disrupted (noted on oral stereognostic findings, which are not discussed in this paper), is an important factor in formulating an internal representation of the articulatory form. 4. Reduced Speech Rate Finally a most significant observation was that all cases, par- ticularly A.M., tended to reduce speech rate during their strug- gle with successive attempts towards the target utterance. This together with their deliberate syllabification of words was seen to aid correct production. This finding seems to highlight the importance of temporal sequencing in articulatory production and has obvious clinical implications. NEUROANATOMICAL FINDINGS The CT scans for each case are presented below (see figures 1, 2 and 3). Figure 1 Case 1: A.M.'s CT scan showing cerebral infarction in- volving mainly the (L) parieto-occipital region and ex- tending towards the island of Reil (insula) on the (L) side. Figure 2 Case 2: F.T. 's CT scan showing cerebral infarcts in the (L) parieto-frontal region involving Broca's area and in the (R) parieto-occipital region. Figure 3 Case 3: E.J.'s CT scan showing cerebral infarction in- volving the (L) parietal region extending towards the'ver- tex and interiorly to the (L) island of Reil (insula) and upper temporal lobe. Table 5 Summary of CT Scan Results for all Cases Case 1 - A.M. Case 2 - F.T. Case 3 - E.J. | - (L) parieto-occipital region, extending towards the island of Reil (insula) on the (L) side a) (L) parieto-frontal region including Broca's area b) (R) parieto-occipital region c I - (L) parietal region, extending towards the vertex, interiorly to the island of | Reil (insula) and upper temporal region on the (L) side moderate degree of cerebral atrophy - generalized cerebral atrophy CT SCAN - asymmetry of lateral ventricles (left larger than right) - asymmetry of lateral ventricles, where (L) lateral ventricle is more dilated than (R) ventricle - widening of Sylvian fissure on (L) side - generalized dilation of ventricular system, and widening of sulci over the vertex - widening of Sylvian fissures bilate- , rally (left more than right) / - no displacement of midline struc- tures - no displacement of midline struc- tures - no displacement of midline struc- tures .. ^ - no abnormal enhancement occurred after contrast - some peripheral enhancement of lesion in (L) Broca's area occurred after contrast - no abnormal enhancement occurred after contrast / The South African Journal of Communication Disorders, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) Phonological and Neuroanatomical Findings in Three Cases with Apraxia of Speech 43 The results will be discussed in relation to current research in the neuroanatomical correlates of language. Each case discussed presents with the major neurological in- sult in the dominant (L) hemisphere. In the cases of A.M. and E.J., the major lesion is in the (L) hemisphere. In the case of F.T., the major lesion is in the (L) hemisphere with a minor lesion in the (R) hemisphere, which is said to have resulted from a mild transient (R) hemispheric cerebral embolus suffered previously. . . . a major function of the left hemisphere is the control of changes in limb or articulatory posture, and its complex verbal and praxic functions are derived from such control. (Kimura, 1977, p. 540) Here Kimura (1977) suggests that the (L) hemisphere contains a system specialized particularly for producing the correct ar- ticulatory posture, and consequently also for controlling the transition from one position to another. Halsey, Blauenstein, Wilson and Wills (1980) studied regional cerebral blood flow measurements in normal speakers and speakers with brain le- sions. They found that in normal speakers during verbal acti- vation, there were significant increases above rest level in the inferior frontal region, roughly corresponding to Broca's area. There were no significant differences between (L) and (R) hemisphere regions. According to Halsey et al. (1980), this rela- tive symmetry of response suggests that probably relatively little intellectual effort is involved in ordinary speaking, and that the bilateral inferior frontal principle activation mainly reflects bilateral cortical control of the muscles of articulation. Fur- ther measurements were made during attempted speaking in patients with (L) and (R) hemisphere lesions. In the (L) hemisphere lesion group, the largest flow changes were in the inferior frontal and temporal regions bilaterally. The only inter- hemispheric significant difference was in the parietal region in the (L) hemisphere lesion group. These findings are of par- ticular interest in relation to the neurological findings of the cases in the present study. It may be observed that CT scans for ea£h case revealed involvement of the parietal region. x I Many years ago Liepman forecast that lesions permitting the appearance of apraxia ('facial apraxia' and 'apraxic dysarthria' now referred to as 'apraxia of speech') would be found in the parietal lobes, in the pre- and post-central gyri and the foot of the first two frontal gyri, with the subjacent part of the cen- trum semi-ovale, and the corpus callosum (Nathan, 1947). Ac- cording to Buckingham (1979), the supramarginal gyrus is a crucial zone for the discussion of apraxia in general and of apraxia of speech. He states that: Although it is a cortical area of the parietal lobe strategically located for the language zones, it is also anatomically quite near the arcuate fasciculus fibers traveling through opercular regions. (Buckingham, 1979, p. 212.) Lebrun, Buyssens and Henneaux (1973) describe a' single case with 'pure anarthria' who suffered a vascular accident in the (L) parietal lobe. The patient presented clinically with aprax- ia of speech, an absence of bucco-facial apraxia and no para- lysis. In a more recent case study, investigations of an apraxic patient showed a lesion in the (L) parietal region (Di Simoni and Darley, 1977). Itoh, Sasanuma, Hirose, Yoshioka and Ushijima (1978) reported on CT scan findings in a patient with apraxia of speech, indicating an infarct involving the cortical surface near the anterior tip of the Sylvian fissure of the (L) hemisphere and the immediately subjacent white matter. F.T.'s CT scan revealed a well marked lesion in Broca's area on the (L) side. Evidence in the literature suggests that a le- sion in Broca's area will result in disintegration of skilled co- ordinated movements of the articulatory organs, referred to as motor apraxia of speech (Whitaker and Seines, 1975; Mohr, Pessin, Finkelstein, Funkenstein, Duncan and Davis, 1978). It is probably not possible to identify a unitary aspect of speech with a delimited cortical area in the narrow sense, given the present state of our knowledge and methodology. While Bro- ca's area is not felt to have a unitary function, there is recent evidence to support the general hypothesis that Broca's area is specialized for certain expressive (motor) components of lan- guage, particularly speech or articulatory parameters (Whitaker and Seines, 1975). Goodglass and Geschwind (cited in Whitaker and Seines, 1975, p. 92) have stated that: . . . injuries in this area (Broca's Area) appear to implicate most directly but not exclusively the phonological and graphic aspects of language. In a recent study, Ruff and Arbit (1981) describe a single case with 'aphemia' (apraxia of speech), whose CT scan reflects in- jury extending from Broca's area to the inferior left precentral gyrus. These writers suggest that the articulatory disturbance which they refer to as 'aphemia' may have resulted from dis- ruption of the connection between Broca's area and the por- tion of the motor cortex that controls oral and pharyngeal muscles. Mohr et al. (1978) have found that when a lesion lies outside Broca's area and focally affects other adjacent sites in the operculum or insula, and even in a few instances apparent- ly affects the deeper structures alone, the resulting syndromes are remarkably uniform, including dyspraxia and faint evidence of language disturbance. This provides some support for the findings in the present study, where a clearly identified lesion in Broca's area was observed on the CT scan for F.T., but not for A.M. and E.J. The neuroanatomical findings in each case under study reflect lesions in the areas similar to those described in Broca's origi- nal patient. Broca, in describing the brain of his original aphasic patient, noted a large lesion encompassing the (L) insula, fron- tal, central and parietal operculum, and even extending into the adjacent inferior parietal region posterior to the Sylvian fissure (Mohr et al., 1978). He attributed this patient's aphasia to involvement of the frontal operculum, but not to the overall lesion. Thus we see his readiness to emphasize only a small, focal portion of the overall lesion. Mohr et al. (1978) feel that by modern standards, the initial physiologic basis for Broca's clinico-pathological correlations seems dubious, and yet, the concept of an aphasia produced by infarction of the Broca area has persisted. Recent literature thus highlights the constraints produced by dogmatic adherence to the traditional formula- tion of the syndrome referred to as Broca's aphasia, resulting from infarction of the Broca's area. It is currently felt that the syndrome arises from a considerably larger brain injury in the Sylvian region, that encompasses most of the operculum, in- sula and subjacent white matter in the territory of the middle cerebral artery serving the dominant cerebral hemisphere; thus far exceeding Broca's area. This in fact conforms more to the Die Suid-Afrikaanse Tydskrif vir Kommunikasieafwykings, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) 44 Lesley Wolk large zone of damaged brain actually present in Broca's origi- nal cases (Roch-Lecours and Lhermitte, 1976). Mohr et al. (1978) together with Whitaker and Seines (1975) contend that Broca's aphasia emerges as a residuum of a larger infarct which initially produces global aphasia. They suggest that there is a gradual emergence of stereotypes, agrammatism and protract- ed apraxia of speech which evolve slowly towards the long-standing deficit profile of Broca's aphasia. CONCLUSION From the discussion above, it is concluded that there is a cer- tain lawfulness to the apraxic impairment in these adult aphasic patients. Articulation errors on single consonants and con- sonant clusters were characterized by systematic rule-governed behaviour. In each case, it was possible to trace underlying phonological processes which fit into strategy groups opera- tionalizing particular phonetic preferences. The major process groups included a tendency for less complex syllable struc- tures to replace more complex ones, a tendency towards pho- netic symmetry and a tendency for errors to result from a lack of feature contrasts. In syllable structure processes, cluster reduction, deletion of final consonants and weak syllable de- letion were most common. Harmony processes were general- ly common, where assimilations occurred more frequently than metatheses and regressive assimilations outnumbered progres- sive assimilations. In feature contrast processes, fronting and stopping were clearly most common. Similar error trends oc- curred on both singletons and clusters for all cases. Analysis from a coarticulatory point of view indicated that some 'future scanning' appeared to be operating in these patients with apraxia of speech, resulting in assimilatory processes, feature merging and feature metathesis. It is thus argued that the im- pairment in these cases may not be confined to the motor as- pects of speech, but probably extends into the linguistic spheres as well. This suggests that descriptions of apraxia of speech and clinical treatment regimes should perhaps consider both linguistic and articulatory variables. All cases employed a number of strategies to aid phonological production. This has several theoretical implications. In par- ticular, revisualization of the written word and the use of si- lent articulations may indicate the preservation of relatively intact implicit speech patterns in these cases. All cases made several errors which were semantically related to the target word, yet fully explicable phonologically. This, combined with the fact that a carrier phrase with semantic relevance was often employed to aid phonological production, would suggest simul- taneous semantic and phonological processing in these cases. This highlights direction for further research into the simul- taneous processing or overlap between the levels of language in the aphasic patient. Reduced speech rate was seen to facili- tate improved phonological production, which may suggest a disruption in timing for these cases. The neuroanatomical findings suggest that apraxia of speech in these cases may result from some synergistic interaction be- tween several areas of the brain rather than a specific local- ized area. This is in agreement with the view proposed by Roch-Lecours and Lhermitte (1976) who suggest that particu- lar language functions may be the result of an interaction of the entire opercular and insula regions. The findings indicate that apraxia of speech for these subjects does not appear to exist as a separate entity, but rather as a part of the total aphas- ic breakdown. Parietal involvement suggests that enhanced kin- aesthetic awareness and tactile discrimination of speech sounds should perhaps be more emphasized in therapy than has previ- ously been considered. The fact that the brain lesion in each case was more extensive than would be expected in the tradi- tional concept of a focal lesion in Broca's area, would seem to suggest an orientation away from rigid diagnosic differenti- ation between Broca and Wernicke aphasic types. In this way, the speech pathologist might take cognisance of symptoms which could otherwise be overlooked. A phonological process analysis may form the basis for thera- py by providing a way of describing the adult aphasic's phono- logical system as an entity, and allowing the clinician to isolate individual phonological processes contributing to unintelligi- bility. Entire processes may thus be the focus of therapy rather than isolated sounds. Clinically, it may be useful to explore the value of graphic symbols, covert articulatory movements and enhanced kinaesthetic awareness in the management of pa- tients with apraxia of speech. In addition, treatment procedures involving rhythm, rate and syllable timing might be fruitful for future research. It is hoped that these findings will stimulate future investiga- tions to improve both diagnostic and therapeutic efficacy and contribute to the endless search in understanding one of the most complex disorders of the human brain. ACKNOWLEDGEMENTS The writer wishes to offer her sincere thanks to Professor M. L. Aron, Head of the Department of Speech Pathology and Audio- logy and Dr. C. Penn, Senior Lecturer in the Department of Speech Pathology and Audiology, University of the Witwaters- rand, for their guidance and support in carrying out this research. 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Die Suid-Afrikaanse Tydskrif vir Kommunikasieafwykings, Vol. 31, 1984 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2) GSI 28 Auto Tymp The GSI 28 AUTO TYMP provides testing capability for tympanometry, ipsilateral and contralateral acoustic reflex testing and screening audiometry. Selection of test sequence is as simple as pressing a button! The" Auto Tymp is lightweight and compact so it can be easily moved from one location to another. An optional carrying case is available if more portability is required. The Needier Westdene Organisation (Pty) Limited In association with / In medewerking met HEARING AND ACOUSTIC INSTRUMENTS (PTY) LTD LEWIS'S HEARING CENTRE (PTY) LTD ENGINEERED ACOUSTIC PRODUCTS NOISE CONTROL Needier Westdene House, 33 Durham St., Raedene, P.O. Box 28975, Sandringham 2131, South Africa. Johannesburg 2192, South Africa. Telex: 4-25028. Tel: (011) 640-5017. Cables: Needlerog. 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