Writing two words as one: Word boundary errors in a German case of acquired surface dysgraphia

Journal of Neurolinguistics 22 (2009) 74e82 www.elsevier.com/locate/jneuroling

Writing two words as one: Word boundary errors in a German case of acquired surface dysgraphia Tobias Bormann a,*, Claus-W. Wallesch b, Margret Seyboth c, Gerhard Blanken c a

Department of Neurology, University of Freiburg, Breisacher Straße 64, D-79106 Freiburg, Germany b Department of Neurology, University of Magdeburg, Magdeburg, Germany c Department of Linguistics, Psycholinguistics, Erfurt University, Erfurt, Germany Received 1 February 2008; received in revised form 18 June 2008; accepted 23 June 2008

Abstract Patients with surface dysgraphia are assumed to have an impairment of a lexicalesemantic writing routine. In line with the suggested functional deficit, words with irregular orthography, particularly such of low frequency, are affected. Typically, errors are phonologically plausible (e.g., laugh/laf) suggesting the use of a sublexical phonological writing route. In the present brief report, a patient (MO) with surface dysgraphia was required to write phrases to dictation. Frequently, he reproduced short phrases (‘‘lass das’’, ‘leave it’) as one word () and tended to delete such segments that are deleted during syllabification in spoken production. For example, MO wrote ‘‘kannst du?’’ (‘can you?’), formally spoken as /kanst du:/ but usually spoken as /kanstu:/, as . It is suggested that the patient uses ‘phonological words’ (syllabified phonological representations; cf. Levelt, W. J. M., Roelofs, A., & Meyer, A. S. (1999). A theory of lexical access in speech production. Behavioral and Brain Sciences, 22, 1e75.) as input to his phonemeegrapheme conversion mechanism. Ó 2008 Elsevier Ltd. All rights reserved. Keywords: Acquired dysgraphia; Surface dysgraphia; Sublexical spelling of phrases

* Corresponding author. Fax: þ49 761 270 5310. E-mail address: [email protected] (T. Bormann). 0911-6044/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jneuroling.2008.06.002

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1. Introduction Patients with ‘‘surface dysgraphia’’ are relatively good at writing nonwords and regularly spelled words while their writing of words with ambiguous or irregular phonemeegrapheme correspondences often contains so-called ‘‘phonologically plausible errors’’ (e.g., Beauvois & De´rouesne´, 1981; Marshall, 1987; Tainturier & Rapp, 2001; see De Bleser, Bayer, & Luzzatti, 1987; Domahs, De Bleser, & Eisenberg, 2001, for German case reports). These errors are assumed to reflect deficient use of permanent representations of the correct spelling of words which follows from impaired access to the orthographic lexicon. Instead, the patients make use of a sublexical spelling routine which unimpaired writers presumably use to write new words. In the case of nonlexical spelling, a person is assumed to analyze a phonological string into phonological segments and then to transform these segments into their respective graphemes. Within models of normal oral language production, different levels of phonological processing have been postulated. In Levelt, Roelofs, and Meyer (1999) model, a level of abstract phonological segments is assumed. These segments are submitted to the process of syllabification, i.e., fitting the segments into a metrical frame. The metrical frame of each morpheme is also stored in the lexicon (see Goldrick & Rapp, 2006, for a review of alternative positions). Syllabification results in ‘phonological words’ which may not correspond to the original morphemes (as in the example ‘select us’ which results in ‘selec-tus’). In the present study, a patient with surface dysgraphia is tested on the writing of phrases to dictation. 2. Patient background MO is a right-handed man born April 1930. He is a retired technician who has travelled extensively in Eastern Europe as part of his profession. He leads an active life and enjoys gardening and family meetings. In July 2000, he experienced a left-sided CVA which left him with aphasia with fluent spontaneous speech with numerous phonemic and some semantic paraphasias. His comprehension at the single word level was well preserved, and conversation about every day activities could be carried out with only minor difficulties. Phonological deficits, however, posed a considerable obstacle during spontaneous speech. Computerized tomography from April 2003 (Fig. 1) shows hypodense areas in superior left temporal areas as well as in the temporaleparietal junction. MO performed within the normal range on the Tower of London test and demonstrated good retention in the Corsi Block Tapping Test (tapping span forward: six items). His verbal working memory was limited to three digits in overt recall and matching. On the overt reproduction of 10 lists of two words (one-syllable), he was correct on only five lists. In spelling tasks, a large number of phonologically plausible spelling errors were observed which led to the detailed investigation of MO’s spelling and the following experimental investigations. 2.1. Assessment of language functions MO was assessed with the Aachen Aphasia Test (AAT; Huber, Poeck, Weniger, & Willmes, 1983). Based on the ALLOC classification software, MO was diagnosed with

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Fig. 1. MR scan of MO showing left posterior lesions.

‘‘Wernicke’s aphasia’’. AAT scores are listed in Table 1. However, with the exception of his Token Test performance, MO met all criteria for conduction aphasia (Huber et al., 1983, p. 76) which is in line with his preserved single word comprehension and the overall clinical impression. Poor Token Test performance may be related to MO’s impaired verbal short-term memory. The Token Test of the AAT is divided into five parts of 10 commands each. Parts 1e4 include orders with increasing numbers of ‘crucial pieces of information’ (part 1: two ‘pieces of information’, e.g., ‘‘Point to the blue square.’’; part 4: six pieces of information, e.g., ‘‘Point to the small yellow circle and the large blue square.’’). Part 5 combines working memory load with syntactic complexity. MO’s number of correct responses for parts 1e3 were 4/10, 1/10, and 2/10. Parts 4 and 5 had to be aborted as MO was unable to follow the commands. This suggests that Token Test performance was affected by MO’s poor verbal short-term memory (cf. Caplan & Waters, 1999). Note that even the shortest commands of the Token Test exceed MO’s memory span which was between one and two words. In a standard naming test (Blanken, Do¨ppler, & Schlenck, 1999), MO correctly named 38 of 60 pictures. Errors consisted of semantic paraphasias (n ¼ 6), ‘don’t know’ responses (n ¼ 2), two picture mis-identifications (n ¼ 2), and phonemic paraphasias (n ¼ 12). Naming was influenced by length (c2(2) ¼ 17.6, p < 0.01), but not by frequency (c2(1) ¼ 1.8, p > 0.15) indicating a postlexical impairment. Receptive phonological processing was assessed with three tests from the ‘‘LeMo’’battery (De Bleser, Cholewa, Stadie, & Tabatabaie, 2004) which revealed unimpaired performance (see Table 2). MO was further confronted with spoken words for which he had to identify the respective picture. Two distractor pictures were phonologically related foils (Blanken, 1999). He was correct on 144 of 150 trials, spontaneously correcting one

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Table 1 MO’s results on the Aachen Aphasia Test (AAT) AAT subtest

Raw score

Percentile rank

Spontaneous speech Token Test (corrected for age) Repetition Naming Written language Comprehension

2-5-5-4-3-3 37 Errors 89/150 89/120 55/90 105/120

e 33 34 62 57 92

Spontaneous speech is rated for communicative behavior; articulation and prosody; automatic speech; semantic structure; phonemic structure; and syntactic structure. Raw scores in spontaneous speech lie between 0 and 5.

of his errors. Taken together, these results indicate well preserved phonological and lexical input processing. Tests of semantic comprehension revealed a very mild deficit of auditory language comprehension. In a semantic comprehension test (Blanken, 1996), MO made no error on a visual wordepicture matching task (matching a word to one of six objects, all six objects from the same semantic category) but made three errors in the auditory version. However, he spontaneously corrected all these errors without the experimenter’s intervention. One test of auditory synonym decision (‘LeMo’ subtest 25, ‘‘auditory synonym decision’’) revealed minor impairments (36/40 correct, unimpaired range 37e40). In two tests of nonverbal semantics (Pyramids and Palmtrees test, Howard & Patterson, 1992; Bogenhausener SemantikUntersuchung, Glindemann, Klintwort, Ziegler, & Goldenberg, 2002), performance was unimpaired. Repetition was clearly impaired. MO correctly repeated only 26 of 45 one-syllable nonwords (‘LeMo’ subtest 8). His 19 errors consisted of word responses (n ¼ 7), deviation by one segment (n ¼ 8) and deviation by more than one segment (n ¼ 4). Of the 60 real words from the test of Blanken et al. (1999), he correctly repeated 45. Errors consisted of phonemic paraphasias and a formally related lexical response. He exhibited an influence of length (onesyllable words: 18/20 correct; two-syllable words: 16/20 correct; three-syllable words: 11/20 correct; c2(2) ¼ 6.9, p < 0.05). Table 2 Performance on tests of semantic and phonological processing Test

Raw score

Comment

Phonological input processing Same/different, words (LeMo subtest 1) Same/different, nonwords (LeMo subtest 2) Auditory lexical decision (LeMo subtest 3)

69/72 69/72 77/80

Unimpaired Unimpaired Unimpaired

49/52

Unimpaired All unimpaired

Verbal semantics Visual wordepicture matching Auditory wordepicture matching

20/20 17/20

Unimpaired Mildly impaired

Auditory synonym decision LeMo subtest 25

36/40

Mildly impaired

Nonverbal semantics Pyramids and Palmtrees (Howard & Patterson, 1992) BOSU, five subtests (Glindemann et al., 2002)

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2.2. Assessment of MO’s spelling of single words Since MO made many orthographic errors, we assessed spelling before his illness. Two postcards containing 170 words were analyzed for spelling errors. These postcards had been written by MO prior his illness. There were four spelling errors resulting in an error rate of 2.4%. Furthermore, in the context of our investigations, MO demonstrated correct spelling of a number of irregular words (e.g., ‘Aal’ [‘eel’]). MO was also able to distinguish his own mis-spelled words from correctly written words in a forced choice task (35/37 correct). This indicates that MO had acquired orthographic lexical representations prior to his illness which he was still able to use in a lexical decision task. Four years after MO’s stroke (June 2004), 969 words were presented to him for handwritten spelling during the assessment of his spelling. The results on these words are presented as supplementary materials (see below for a description of error types). As Supplementary Table A shows, many of his segmental errors (62% and 17%) were phonologically plausible renderings of a word’s correct spelling. Moreover, there were significant effects of frequency (high frequency: 100/200 correct; low frequency: 69/200 correct; c2(1) ¼ 9.8, p < 0.01), concreteness (concrete: 103/220 correct; abstract: 31/220 correct; c2(1) ¼ 11.7, p < 0.01), and phonemee grapheme regularity (regular: 99/200 correct; irregular: 58/200 correct; c2(1) ¼ 17.6, p < 0.01; Supplementary Table B). The many errors even for regular target words result from an additional impairment at the peripheral level of spelling.1 Therefore, the following tasks were carried out with letter tiles. Capital letters were printed on small card board plates of about 1  1 inches. All letters were arranged in alphabetical order on a table in front of MO, and each letter appeared at least three times. MO heard the word to be spelled and arranged the letters on the table. After his response, all letters were returned to the alphabet. No peripheral errors were observed in this task. Target items came from the spelling subtests of the ‘LeMo’-battery. The results with letter tiles are given in Table 3. MO’s responses with letter tiles were classified as ‘correct’, ‘formal errors’ (nonsemantic lexical substitutions with phonological similarity), ‘omissions’ (those few items which he was unable to repeat due to his phonological deficit), segmental errors deviating from the target Table 3 Variables influencing MO’s word spelling (with letter tiles) Subtest

Variables tested

Score

Percent

LeMo 21 (nouns)

Concrete Abstract High frequency Low frequency Regular Irregular

15/20 7/20 13/20 9/20 10/20 12/20

75 35 65 45 50 60

LeMo 22 (word class)

Nouns Adjectives Function words

17/30 13/30 15/30

57 43 50

LeMo 20 (nonwords)

Nonwords

33/40

83

Significance p < 0.05 Not significant Not significant

Not significant

1 Several of MO’s letter substitutions were influenced by visual or motor similarity (e.g., ‘‘grau’’/; ‘‘Kran’’/) which has been taken to reflect impaired selection of allographs or abstract grapho-motor patterns. Such form-based substitutions did not occur in spelling with letter tiles.

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Table 4 MO’s errors in spelling to dictation with letter tiles Reaction

Example

A) Correct B) Deviation by one segment phonologically plausible errors in B

hohl/hol

C) Deviation by more than one segment phonologically plausible errors in C

vor/fur

D) Formal errors F) Omissions

schlau/Schal zwar/.

Frequency 67 34 21 (62%) 17 4 (24%) 10 2

by one segment (e.g., ‘‘wir’’/) and segmental errors deviating by more than one segment (e.g., ‘‘Grund’’/). A large proportion (62%) of errors deviating by one segment were phonologically plausible errors (see Table 4). Verbs are not included in the subtests of LeMo. However, to include verbs in our analysis, we presented MO 24 verbs for dictation (with letter tiles). Twelve had regular spelling (6 high frequency [HF], 6 low frequency [LF]), 12 had ambiguous spelling (6 HF, 6 LF). MO was correct on 6/12 regular verbs (3/6 HF, 3/6 LF) and on 4/12 verbs with ambiguous spelling (3/6 HF, 1/6 LF). MO’s pattern of his writing impairments matches ‘surface dysgraphia’: First, there were significant effects of phonemeegrapheme regularity in his handwritten responses (see Supplementary Table B). Second, a large proportion of his segmental errors, both in handwriting and spelling with letter tiles, were phonologically plausible spellings. 2.3. Spelling of homophones with sentence contexts A test was carried out to further assess MO’s functional spelling impairment. He was dictated 30 heterographic homophone words with spoken context sentences (e.g., ‘‘Schreiben Sie das Wort ‘Wal’ (/va:l/) wie in ‘An der Ku¨ste strandet ein Wal.’ ‘Wal’’’ e ‘Write ,wale’ as in ‘Awale stranded at the coast.’ ‘wale’, as opposed to ‘‘Wahl’’ (/va:l/) meaning ‘election’ or ‘choice’). To assess whether MO had understood the context sentence, an additional pair of words was presented visually. Only one matched the meaning of the sentence (e.g., ‘‘Meer’’ (‘sea’) vs. ‘‘Tasse’’ (‘cup’)). MO pointed to the correct word in 29 of 30 trials indicating preserved comprehension of the sentences. In contrast, he was wrong on 12 written responses of the 30 spoken homophones. Ten errors were a confusion of the homophones with MO choosing the homophone twin. Two errors were phonologically plausible. Thus, despite preserved sentence comprehension, he wrote the wrong homophone twin in a number of trials. This suggests that MO suffered from a deficit at the level of the orthographic output lexicon and relatively preserved semantic processing of the stimuli. 3. Experimental investigations 3.1. Experiment: writing of phrases MO was dictated short phrases and questions like ‘‘Ho¨r auf!’’ (‘Stop it!’) and ‘‘Willst du?’’ (/vilstu:/ e ‘do you want?’). He was asked to repeat the phrase and then spell it by using capital letter tiles (see above). It proved impossible for him to write words and phrases without first repeating them correctly. Phrases were presented in random order and with nounenoun

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compounds and simple nouns as fillers. In German orthography, compound nouns are written as one word although they consist of two morphemes (e.g., ‘‘Tischdecke’’ [‘tablecloth’]). MO was informed that the stimuli may consist of more than one word, and he was asked to pay attention to word boundaries in his response. MO readily understood the instructions and did identify word boundaries clearly in each response. No ambiguous responses were noted. There were three conditions: (1) frequent short phrases which contained ‘phonological blends’ of two words, in which single phonemes cannot be perceived, yet have to be written (n ¼ 20; e.g., ‘‘willst du?’’ [‘do you want?’], formally spoken as /vilst du:/ [two phonological words], but usually spoken as /vilstu:/ [one phonological word]); (2) frequent short phrases (questions, orders) without ‘phonological blends’ (e.g., ‘‘gut so?’’ [/gu:tso:/]; n ¼ 35); and (3) control phrases (full questions and sentences) without ‘phonological blends’ (e.g., ‘‘Darf ich gehen?’’ [‘May I go?’]; ‘‘Sie lachen.’’ [‘They laugh.’]; ‘‘Wir gehen heim.’’ [‘We are going home.’]; n ¼ 20). Two kinds of errors were observed which could appear in the same phrase: (1) linking two words of the phrase (‘‘geh raus’’ [‘go out’]/), and (2) leaving out segments which could not be perceived from the auditory stimulus, or assigning segments to the following words (‘‘segmental error’’; e.g., ‘‘kannst du?’’ [/kanstu:/]/). The results of the experiment are presented in Table 5. There was a significant advantage for control phrases over the combined experimental conditions with regard to correctly spelled phrases (c2(1) ¼ 16.2, p < 0.01). Thus, there were more errors in the two experimental conditions than in the control phrases. When both experimental conditions were compared individually to the control condition, the advantage of the control condition still was significant (‘with blends’ vs. control: c2(1) ¼ 24.0, p < 0.01; ‘without blends’ vs. control: c2(1) ¼ 9.7, p < 0.01). Finally, there were more correctly spelled phrases in the experimental condition ‘without blends’ when compared to the experimental condition ‘with blends’ (c2(1) ¼ 7.3, p < 0.01). The segmental errors were limited to experimental phrases and did not occur with control phrases. Interestingly, errors in which a segment was omitted or assigned to the wrong morpheme did not occur for experimental phrases without ‘phonological blends’. In addition, MO frequently wrote compound nouns as two single words (e.g., ‘‘Postbote’’ [‘postman’] as ).2 Table 5 MO’s results in the writing of phrases Response type

Phrases without phonological blends Phrases with blend Control phrases 2

Separate, without segmental error (‘correct’)

Two words as one, without segmental error

Two words as one, with segmental error

Separate, with segmental error

Sum

22

13

0

0

35

5 20

4 0

4 0

7 0

20 20

MO’s difficulties in writing phrases to dictation were not, however, confined to spelling with letter tiles. All errors which were observed in spelling with letter tiles could also be observed when MO used handwriting (e.g., ‘‘lies vor’’ [‘read!’]/; ‘‘Gartenzwerg’’ [‘garden gnome’]/). Therefore, the errors occurred independently of the mode of responding.

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To assess the potential role of impaired verbal short-term memory (vSTM) in writing phrase, we compared MO’s errors to the errors of a patient (IS) with a selective impairment of vSTM. IS was born in 1954 and suffered from a ruptured cerebral aneurysm in her right internal carotid artery in May 2000. Three days after surgical treatment of a second aneurysm, she suffered from an ischemic stroke. IS had lesions in right frontal and left inferior parietal areas. Apart from occasional word finding errors, paragrammatic errors in spontaneous speech and impaired Token Test performance, speech comprehension and production were preserved. In contrast, her verbal memory spans were severely impaired (digit span around 4; word span between 2 and 3). In the digit span of the Wechsler Memory Scale (WMS-R), her score was low (raw score: 4; percentile rank < 3). She was unable to repeat longer compound words and sentences. IS wrote 20 phrases to dictation and used letter tiles (as described above). She was correct on 19 of the phrases. Her only error was a spelling error (‘‘weißt’’/). There were no violations of word boundaries. Therefore, impairment of vSTM, at least the ‘storage part’ of vSTM, does not appear to contribute to MO’s impairment in the writing of phrases. We have, however, no clue whether MO’s impaired spelling of phrases was, in part, caused by his impaired phonological encoding. Future research with patients with ‘surface dysgraphia’ but without impairment to postlexical phonological encoding may clarify this issue. 3.2. Control experiment: comprehension of phrases It may be argued that MO perceived the dictated phrases as nonwords. In this case, he may process a string of phonemes free of meaning and without involvement of lexical processes. This would explain his impaired spelling of the phrases. Two arguments may be taken against this alternative explanation: First, his comprehension deficits were very mild at best. Second, his difficulties in the writing of homophones suggest persistent impairments in the context of relatively preserved semantic processing. However, since different materials were used for these different tasks, a further experiment was designed to assess comprehension of exactly those phrases which had been included in phrase spelling. There were 50 phrases, all of which had been used in the experimental conditions (1) and (2), for which MO was shown two pictures. Only one picture matched the phrase. Care was taken that pictures could not be identified based on single words in the phrase. MO was correct on 45 of 50 phrases (90%), a result significantly different from chance ( p < 0.01). This further indicates his preserved comprehension of those phrases which had led to spelling errors and lends further support to our conclusions. 4. Discussion The patient of the present study, MO, exhibited symptoms of ‘‘surface dysgraphia’’. Writing to dictation of phrases may pose specific difficulties for a patient who has to rely on sublexical spelling mechanisms. In our study, writing of phrases resulted in two types of errors: First, an inability to recognize word boundaries resulting in a large proportion of phrases that were ¨ RAUF>); second, the omission and respelled as one word (‘‘ho¨r auf’’ [‘stop it!’]/). Occurrence of these errors depended on the presence of syllabifications which did not match morpheme boundaries. There were more errors in those experimental conditions in which syllable boundaries did not match word boundaries. However, there was no general tendency of MO to write phrases as one continuous string of graphemes as he was well able to keep morphemes separate in control

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sentences. Furthermore, we argued that MO did not treat these phrases as unknown phoneme strings as he was reliably able to match these phrases to pictures. We would argue that MO, due to his surface dysgraphic spelling impairment, was unable to use orthographic knowledge about morphemes. Instead, he relied on syllabified phrases, ‘phonological words’ in Levelt et al.’s (1999) terms, and used these for spelling. Due to his impairment in accessing lexical information, orthographic lexical representations could no longer be used to guide spelling of phrases. We think that, like phonologically plausible errors in single word errors, these errors reflect the predominant use of a sublexical spelling strategy. It demonstrates that, at least in our patient, phonological information did override information about the lexical and morphological status in the orthographic domain. The present study, thus, adds to the symptoms of surface dysgraphia, a disorder quite commonly observed in language impaired patients. Acknowledgments We are grateful to MO for his patient and good-humored participation in this research and to Angelika Barasch, speech therapist in Erfurt, for referring MO to our laboratory. An anonymous reviewer provided helpful comments on a previous version of this manuscript. Supplementary data Supplementary data associated with this article can be found in the online version at doi:10.1016/j.jneuroling.2008.06.002. References Beauvois, M.-F., & De´rouesne´, J. (1981). Lexical or orthographic agraphia. Brain, 104, 21e49. Blanken, G. (1996). Auditives Sprachversta¨ndnis: Wortbedeutungen. Visuelles Sprachversta¨ndnis: Wortbedeutungen. Materialien zur neurolinguistischen Aphasiediagnostik. Hofheim: NAT-Verlag. Blanken, G. (1999). Auditives Sprachversta¨ndnis: Wortformen. Materialien zur neurolinguistischen Aphasiediagnostik. Hofheim: NAT-Verlag. Blanken, G., Do¨ppler, R., & Schlenck, K.-J. (1999). Wortproduktionspru¨fung fu¨r Aphasiker. Materialien zur neurolinguistischen Aphasiediagnostik. Hofheim: NAT-Verlag. Caplan, D., & Waters, G. (1999). Verbal working memory and sentence comprehension. Behavioral and Brain Sciences, 22, 77e126. ¨ berblick mit De Bleser, R., Bayer, J., & Luzzatti, C. (1987). Die kognitive Neuropsychologie der Schriftsprache e Ein U zwei deutschen Fallbeschreibungen. Sonderheft. Linguistische Berichte, 1, 118e162. De Bleser, R., Cholewa, J., Stadie, N., & Tabatabaie, S. (2004). Lexikon modellorientiert. Mu¨nchen: Urban & Fischer. Domahs, F., De Bleser, R., & Eisenberg, P. (2001). Silbische Aspekte segmentalen Schreibens e neurolinguistische Evidenz. Linguistische Berichte, 185, 13e26. Glindemann, R., Klintwort, D., Ziegler, W., & Goldenberg, G. (2002). Die Bogenhausener Semantik-Untersuchung (BOSU). Mu¨nchen: Urban & Fischer. Goldrick, M., & Rapp, B. (2006). Lexical and post-lexical phonological representations in spoken production. Cognition, 102, 219e260. Howard, D., & Patterson, K. (1992). The pyramids and palmtrees-test (PPT). Bury St. Edmunds/Thames Valley. Huber, W., Poeck, K., Weniger, D., & Willmes, K. (1983). Der Aachener Aphasie test (AAT). Go¨ttingen: Hogrefe. Levelt, W. J. M., Roelofs, A., & Meyer, A. S. (1999). A theory of lexical access in speech production. Behavioral and Brain Sciences, 22, 1e75. Marshall, J. C. (1987). Routes and representations in the processing of written language. In E. Keller, & M. Gopnik (Eds.), Motor and sensory processes of language (pp. 237e256). Hillsdale, NJ: Lawrence Erlbaum. Tainturier, M.-J., & Rapp, B. (2001). The spelling process. In B. Rapp (Ed.), Handbook of cognitive neuropsychology: What deficits reveal about the human mind (pp. 263e289). Hove: Psychology Press.