Acquired Dysgraphia in Alphabetic and Stenographic Handwriting

NOTE ACQUIRED DYSGRAPHIA IN ALPHABETIC AND STENOGRAPHIC HANDWRITING Gabriele Miceli1, 2, 3, Rita Capasso1, 2, Alessandra Ivella2 and Alfonso Caramazza4 (1Istituto di Neurologia, Università Cattolica; 2IRCCS S. Lucia, Roma; 3Istituto di Psicologia, CNR, Roma; 4Harvard University)

ABSTRACT We report the unusual case of AZO, who professionally used handwritten shorthand writing, and became dysgraphic after a stroke. AZO suffered fron a complex cognitive impairment, and part of her spelling errors resulted from damage to auditory input processing, to phonology-orthography conversion procedures and to the ortographic output lexicon. However, analysis of her writing performance showed that the same variables affected response accuracy in alphabetic and shorthand writing; and, that the same error types, including transpositions, were observed in all tasks in the two types of writing. These observations are consistent with damage to the graphemic buffer. They suggest that, in multiple-code writing systems (e.g., stenography, Japanese, or in the case of multilingual speakers of languages that use different spelling codes), the graphemic buffer is shared by all codes. INTRODUCTION Stenography is a writing system devised to allow the verbatim transcription of online speech. Stenographic handwriting is faster than alphabetic handwriting, for two main reasons. In the first place, highly frequent letter sequences, bound morphemes and some very highfrequency words (many free-standing grammatical morphemes and a few major-class lexical items) are abbreviated or omitted. Secondly, letters and letter groups correspond to symbols that are easier and faster to trace than the letters of the alphabet (see the Appendix for a brief overview of the shorthand system used by our subject, and Figure 1 for examples of stenographic syllables). Skills like those of the stenographer (i.e., the ability to master two writing codes) are encountered only infrequently in writers of most languages, but they are the rule for writers of some languages, like Japanese. Japanese uses two writing codes, a logographic/ morphographic code (kanji) and a phonological/syllabographic code (kana). Kanji is used to write word roots. Kana is used principally to write suffixes and function words, but also serves as the basic code for spelling unfamiliar words. The dual-code nature of Japanese has prompted several investigations on the consequences of brain damage on the ability to write in kana and in kanji. There have been reports of greater impairment of kanji than of kana (e.g., Iwata, 1986; Kawamura, Hirayama, Hasegawa et al., 1987; Kawamura, Hirayama and Yamamoto, 1989; Soma, Sugishita, Kitamura et al., 1989; Yokota, Ishiai, Furukawa et al., 1990), as well as of the opposite pattern (e.g., Mochizuki and Ohtomo, 1988; Tanaka, Yamadori and Murata, 1987; Tei, Soma and Mariyama, 1994). These selective deficits for kanji and kana writing have been interpreted as being roughly equivalent to “surface” and “phonological” dysgraphia in alphabetic codes, respectively. However, there have been no detailed reports of subjects with similar impairments to the two codes, even though such cases are predicted by current models of the spelling process. Most models of writing assume that graphemic representations for both familiar words Cortex, (1997) 33, 355-367

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Fig. 1 – Examples of syllables written in the stenographic system used by AZO.

and unfamiliar words (nonwords) are temporarily stored in a graphemic buffer prior to being converted into sequences of letters (for written spelling) or letter names (for oral spelling). Because the graphemic buffer is a common end-stage of lexical and non-lexical processes, damage at this level results in comparable impairments of word and nonword spelling. Furthermore, performance accuracy is affected by length but not by lexical factors (e.g., grammatical class; frequency, abstractness/concreteness); in addition, spelling errors result in letter substitutions, insertions, deletions and transpositions (Caramazza, Miceli, Villa et al., 1987). Several patients with selective damage to the graphemic buffer have been reported (e.g., Caramazza et al., 1987; Jonsdottir, Shallice and Wise, 1995; Hillis and Caramazza, 1989; Kay and Hanley, 1994; McCloskey, Badecker, Goodman-Schulman et al., 1994; Miceli, Benvegnù, Capasso et al., 1995; Posteraro, Zinelli and Mazzucchi, 1989). However, no subjects who were premorbidly able to spell in more than one code, and whose impairment involves the graphemic buffer are on record. In such individuals, the spelling impairment should affect the two codes equivalently. Thus, for example, a writer of Japanese should present with equivalently poor performance in kana and kanji, and a stenographer should write poorly both in the alphabetic and in the shorthand codes1. CASE REPORT AZO is a 45-year old, right-handed woman, with a high-school education. Prior to suffering from brain damage, she worked as a professional stenographer, and also taught shorthand writing at a private school. In her profession, she used the handwritten shorthand code. On June, 1990, at age 41, she suffered from a ruptured aneurysm of the tripod of the left sylvian artery, that required surgical treatment. CT-scan, performed 20 days after surgery, is reported as showing extensive ischemic damage to the fronto-parietal structures of the left hemisphere. AZO lives in a small town in Northern Italy, and was first seen 4 years post onset. Since she was only available for 1 month, a control CT-scan could not be performed, and no neuroradiological documentation is available. The neurological exam showed a right hemiplegia and right-sided extinction phenomena on double simultaneous stimulation in the tactile, visual and auditory modalities. Neuropsychological Examination AZO performed well within normal limits on Raven’s Colored Progressive Matrices (35/ 36 correct responses), and on tasks that required the ability to copy drawings, with or without landmarks. She suffered from a severe buccofacial apraxia, and from a moderate limb apraxia

1

To be sure, the parallelism between a stenographer and a writer of Japanese is only partial. The most obvious difference is that writers of Japanese constantly switch codes in writing, even when writing single words, whereas stenographers do not (i.e, they use the two codes in independent contexts). In addition, the distinction between kana and kanji largely overlaps with distinctions of grammatical class (content word roots are written in kanji; grammatical morphemes are written in kana), and of orthographic transparency/opaqueness (the relationship between orthography and pronunciation is transparent in kana, but opaque in kanji). The same contrasts do not hold for alphabetic vs shorthand writing. Both codes have entries for all words, few of which are opaque, and many of which are transparent in both alphabetic and shorthand Italian. In addition, in shorthand abbreviations are used for both frequent letter groups and suffixes, and logograms are used for both content and function words (although more frequently for the latter). However, the similarity between the two dual-code systems discussed here (kana-kanji writing in Japanese and alphabetic-shorthand writing in Italian) is sufficiently substantial to invite investigations that have implications for both systems.

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in the non-plegic left arm; no ideational apraxia was detected. A handedness questionnaire disclosed a strong premorbid preference for the right hand. On memory probe tasks AZO’s performance was within the normal range with nonwords, and mildly below normal with words. AZO repeated correctly only 2/10 series of two bisyllabic words, and failed to reproduce any series of two bisyllabic nonwords (out of 10). This figure overestimates her difficulties, since several errors resulted from minor phonetic/phonemic distortions of the target. However, even if responses that contain minor articulatory disorders are scored as correct, AZO’s performance is still substantially abnormal, as only 7/10 series of words and 2/10 series of pseudowords were reproduced correctly. Language Examination Administration of a screening battery for language disorders (Miceli, Laudanna, Burani et al., 1994) demonstrated a severe, non-fluent aphasia. AZO spoke with a low, dysarthric voice; she also produced clear phonemic errors. She wrote with her left hand, slowly and laboriously, but legibly. Sublexical Processing Tasks Phoneme discrimination was mildly impaired (9/60 incorrect responses, 15%), and auditory-visual matching of syllables was moderately impaired (14/60 incorrect responses, 23.3%). Performance on nonword transcoding tasks was poor. AZO produced 19/36 incorrect responses in repetition (52.7%), 27/45 in reading aloud (60%), 11/25 in writing to dictation (44%), and 0/6 in delayed copy (0%). In all tasks, response accuracy was affected by target length. AZO produced fewer incorrect responses to pseudowords of 2-3 letters (repetition: 9/18, or 50%; reading aloud: 7/15, or 47%; writing to dictation: 3/15, or 20%) than to pseudowords of 4-6 letters (repetition: 11/18, or 61.1%; reading aloud: 21/30, or 70%; writing to dictation: 8/10, or 80%). The comparison between short and long pseudowords reached significance in writing to dictation (chi-square = 6.500; p <.02), but not in repetition (chisquare = 0.113; p = n.s.) and in reading aloud (chi-square = 1.430; p = n.s.)2. All incorrect responses bore a close phonemic/graphemic resemblance to the target. For example, AZO repeated /ga’live/ as /ka’live/, read aloud volidia as /vo’lityo/, and wrote to dictation /kos’pivo/ as cosvito. These results are consistent with damage to all sublexical conversion mechanisms (as well as with a less substantial impairment of phonological input processing). Of particular relevance for our purposes is the fact that phoneme-grapheme conversion procedures were severely impaired. Lexical Processing Tasks Auditory lexical decision was accurate (3/80 incorrect responses, 3.8%); whereras visual lexical decision was poor (18/80 incorrect responses, 22.5%). Word transcoding tasks were also poorly executed. AZO produced 21/45 incorrect responses in repetition (46.7%); 63/92 in reading aloud (68.5%); 18/46 in writing to dictation (39.1%); and 1/10 in delayed copy (10%). Performance on all tasks was influenced by length. If responses to the subsets of 6letter stimuli and 9-letter stimuli are compared, a clear trend towards greater accuracy in responding to short than to long words is observed. AZO repeated incorrectly 1/9 (11.1%) 6-letter words and 5/7 (71.4%) 9-letter words; she read aloud incorrectly 12/20 (60%) 6letter words and 12/14 (85.7%) 9-letter words; and, she incorrectly wrote to dictation 2/8 (25%) 6-letter words and 5/8 (62.5%) 9-letter words. The difference between short and long stimuli reached significance in repetition (chi-square = 5.625; p <.025), but not in reading aloud (chi-square = 1.531, p = n.s.) and in writing to dictation (chi-square = 1.016; p = n.s.). Non-significant effects of grammatical class were also observed (nouns were consistently more preserved than verbs). Stimulus frequency significantly affected reading performance (HF words: 18/30 incorrect responses, or 60%; LF words: 24/30 incorrect responses, or 80%;

2

These results must be interpreted with caution, given the small n’s entered in each analysis.

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chi-square = 8.403; p <.01). Spelling performance is analysed in greater detail later in this paper. Oral spelling was extremely difficult, to the point that AZO refused to perform the task. Word-picture matching tasks (target matched with either semantic or phonemic/visual foils) were at normal levels in the auditory modality (1/40 incorrect responses, 2.5%), and at lower normal levels in the visual modality (3/40 incorrect responses, 7.5%). Picture naming tasks were severely impaired. AZO produced an incorrect spoken response to 21/30 objects (70%) and 21/28 actions (75%), and an incorrect written response to 7/22 objects (31.8%) and to 15/22 actions (68.2%). The incidence of incorrect oral (42/58, 72.4%) and written responses (22/44, 50%) was significantly different (chi-square = 4.461; p <.05). AZO never failed to respond to the stimulus pictures. In spoken naming, a few incorrect responses (13 to objects and 10 to actions) resulted from minor phonetic/phonemic errors, that sometimes occurred on semantically-incorrect responses (spilla, pin → /’ako/, from the distortion of “ago”, needle; versare, to pour → / ’peve/, from the distortion of “beve”, he drinks). All these errors resulted in phoneme substitutions or deletions (e.g., gamba, leg → /’kamba/; radio → /’ratyo/; microfono, microphone → /pi’kro-ono/). Three responses to nouns were also inflectionally related (ciliegia, cherry → ciliegie, cherries). Similarly, 4 written responses to objects and 6 written responses to actions resulted in orthographically-related errors, that sometimes occurred on semantic substitutions (dipinge, he paints → desegna from the distortion of disegna, he draws). All orthographic errors resulted in letter substitutions (accarezza, she caresses → accaressa) and deletions (bandiera, flag → badiera). Interestingly, even though letter substitutions and deletions occurred in both spoken and written naming, letter transpositions occurred only in written naming (usually in the context of complex errors, as soffia, he blows → sfonia; affonda, he drowns → anfona). In order to obtain a better estimate of AZO’s ability to select the appropriate phonological and orthographic lexical entry in response to a picture, a further analysis was conducted on picture naming performance. Incorrect responses resulting in minor phonemic/orthographic distortions were scored as correct, and only incorrect responses unambiguously resulting in the failure to activate the correct target (i.e., semantic substitutions and omissions) were considered to be incorrect. On this criterion, in spoken naming 12/30 (40%) responses to objects and 14/28 (50%) responses to actions were lexically incorrect; and, in written naming 2/22 (8.1%) responses to objects and 8/22 (36.4%) responses to actions resulted in the selection of an inappropriate word form. Thus, overall AZO failed to select the correct lexical form more often in spoken naming (26/58, 44.8%) than in written naming (10/44, 22.7%); chi-square = 4.427, p <.05. The mild tendency toward lesser accuracy in responding to objects (14/52 incorrect responses, 73.1%) than to actions (22/50 incorrect responses, 44%) failed to reach significance (chi-square = 2.550; p = n.s.). AZO’s performance in picture naming results from a complex deficit. The association of fair word comprehension with substantial difficulty in retrieving the correct word form in picture naming tasks suggests damage to the output component of the lexicon; and, greater impairment in spoken than in written picture naming points to more severe damage to the phonological than to the orthographic output lexicon. Furthermore, the occurrence of many segmentally incorrect responses in both spoken and written naming suggests that, in addition to output lexical damage, AZO also suffers from post-lexical deficits. Sentence Processing Tasks AZO produced many incorrect responses on auditory (12/48, 25%) and visual (5/24 29.2%) grammatically judgment tasks. Sentence repetition was also very poor (18/20 incorrect responses, 90%), and replete with “agrammatic” errors (substitutions of bound grammatical morphemes; omissions of free-standing grammatical morphemes and main verbs; agreement violations and tense errors). In reading aloud, 6/6 sentences were reproduced incorrectly and most errors resulted in phonetic/phonemic or visual distortions of the target. AZO also performed very poorly on sentence-picture matching tasks (correct target matched with a foil representing the reversal of thematic roles, or a morphological alternative, or a lexicalsemantic alternative). She produced a comparable number of incorrect responses in the auditory (16/60, or 26.7%) and in the visual task (8/45, 17.8%). The majority of her errors involved the incorrect selection of role reversal foils. Spoken and written narratives (both

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constrained and unconstrained) were severely disrupted. Output was often limited to sequences of nouns, or to the simplest declarative sentences in the active form. In addition to being grammatically incorrect, output was disturbed by obvious word finding difficulties and (in speaking) phonetic distortions. In spontaneous writing, AZO showed a clear tendency to use the same short, high-frequency words over and over. Spelling errors occurred on long words, and resulted in substitutions (logopedista, speech therapist → locopedista), deletions (chiacchierare, to chat → chiaccherare), transpositions (sedie, chairs → seide), and mixed errors (Repubblica, republic → Reppluca). EXPERIMENTAL STUDY Prior to her stroke, AZO was very skilled in shorthand writing. In order to characterize the cognitive impairment responsible for her dysgraphia, and to see whether the shorthand and alphabetic codes were affected in qualitatively and quantitatively similar ways, AZO was asked to write to dictation 155 words and 66 pseudowords in the alphabetic and the shorthand codes. Sessions in which she wrote in the shorthand or in the alphabetic code were alternated, so that a comparable number of responses was produced in shorthand first, or in alphabetic spelling first. Words included sublists controlled for frequency, grammatical class, and length; pseudowords were divided in sublists matched for length. Since AZO was available only for a very short time, some sublists were administered only in part. Quantitative Analysis AZO wrote very slowly and laboriously. However, her output in both codes was always clearly legible, so that problems of interpretation never arose. Even though occasionally she asked for a second presentation of the stimulus, AZO never failed to produce a written response to word and pseudoword stimuli. Her performance is summarized in Table I. She was equally accurate when writing in the alphabetic and in the shorthand code. She produced 102/221 (46.2%) incorrect alphabetic responses, and 104/221 (47.1%) incorrect shorthand responses (chi-square = 0.009; p = n.s.). Response accuracy to words and to nonwords was also comparable across codes. AZO produced 55/155 (35,5%) incorrect alphabetic responses and 53/155 (34.2%) incorrect shorthand responses to words (chi-square = 0.014; p = n.s.), and 47/66 (71.2%) incorrect alphabetic responses and 51/66 (77.3%) incorrect shorthand responses to nonwords (chi-square = 0.357; p = n.s.). Performance consistency in spelling the 221 stimuli (155 words; 66 pseudowords) administered for alphabetic and for shorthand writing was also considered. AZO consistently produced the correct response to 87 stimuli (39.4%) and an incorrect response to 74 (33.5%). She produced only the correct alphabetic response to 32 stimuli (14.5%), and only the correct shorthand response to 26 stimuli (11.8%). The across-code distribution of correct and incorrect responses to the same stimulus does not differ from chance (McNemar’s test = 0.431; p = n.s.). This is also true when the 155 words and the 66 nonwords are analysed separately. AZO wrote 75 words (48.4%) correctly in both tasks, and 31 words (20%) incorrectly in both tasks. She produced only the correct alphabetic response to 25 words (16.1%), and only the correct shorthand response to 24 words (15.5%). This distribution does not differ from chance (McNemar’s test = 0, p = n.s.). With pseudowords, AZO consistently produced the correct response to 12 stimuli (18.2%), and consistently produced an incorrect response to 43 stimuli (65.2%). She produced only the correct alphabetic response to 7 pseudowords (10.6%), and only the correct shorthand response to 4 pseudowords (6.1 %); McNemar’s test = 0.909; p = n.s. To sum up these results, performance in alphabetic writing is quantitatively indistinguishable from performance in shorthand writing. In alphabetic writing tasks, AZO responded more accurately to words (55/155, 35.5%) than to nonwords (47/66, 71.2%), and the difference was statistically significant (chisquare = 22.359; p <.001). She produced incorrectly 23/88 nouns (26%), 8/17 adjectives (47%), 18/30 verbs (60%) and 6/20 functors (30%). Thus, her level of performance was significantly influenced by grammatical class (chi-square = 12.623; p <.01). AZO wrote incorrectly 13/63 (20.6%) words ranging in frequency between 150-50/million, and 33/66

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Incorrect Responses Produced by AZO in Spelling to Dictation 155 Words and 66 Nonwords in Alphabetic Writing and in Shorthand Writing

Words

N

Alphabetic

155

55

Shorthand (35.5)

53

(34.2)

Grammatical class Nouns Adjectives Verbs Functors

88 17 60 20

23 (26.0) 8 (47.0) 18 (60.0) 6 (30.0) chi-square = 12.63 p <.01

27 (30.6) 6 (35.2) 16 (53.3) 4 (20.0) chi-square = 7.046 p = n.s.

Frequency High Low

63 66

13 (20.6) 33 (50.0) chi-square = 15.549 p <.001

13 (26.0) 24 (36.3) chi-square = 3.168 p = n.s.

Abstractness Concrete Abstract

50 35

8 (16.0) 15 (42.8) chi-square = 6.283 p <.02

13 (26.0) 13 (37.1) chi-square = 0.736 p = n.s.

100 38 17

22 (22.0) 20 (52.6) 13 (76.4) chi-square = 25.456 p <.001

22 (22.0) 20 (52.6) 11 (64.7) chi-square = 19.419 p <.001

66

47

50

11 40

9 (81.8) 35 (87.5) chi-square = 0 p = n.s.

9 (81.8) 37 (92.5) chi-square = 0.233 p = n.s.

15 19 32

3 (20.0) 14 (73.6) 30 (93.7) chi-square = 27.302 p <.001

4 (26.6) 17 (89.4) 30 (93.7) chi-square = 28.542 p <.001

Length 4-6 7-8 9-11

Nonwords Morphological structure With Without

Length 2-3 4-6 7-8

(71.2)

(75.6)

words ranging in frequency between 10-1/million, thus demonstrating a significant effect of frequency (chi-square= 15.549; p<.001). Response accuracy was also sensitive to abstractness/ concreteness, as significantly fewer errors were produced to concrete (8/50, 16%) than to abstract words (15/35, 42.8%); chi-square = 6.283; p <.02. Finally, the effect of length was examined by analyzing performance on 100 short (4-6 letters), on 38 intermediate (7-8 letters), and on 17 long words (9 or more letters). Incorrect responses to the three subsets of stimuli increased from 22% (22/100) to 52.6% (20/38) to 76.4% (13/17). The effect of length is statistically rebliable (chi-square = 25.456; p <.001). Alphabetic nonword writing was also significantly affected by length. Performance on 15 short (2-3 letters), 19 intermediate (4-6 letters) and 32 long pseudowords (7-9 letters) was considered. AZO produced 20% (3/15), 73.6% (14/19) and 93.7% (30/32) incorrect responses to the three subsets, respectively (chisquare = 27.302; p <.001). In shorthand writing, AZO produced fewer incorrect responses to words (53/155, 34.2%) than to nonwords (51/66, 77.3%). This difference is statistically reliable (chi-square = 32.773;

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p <.001). Even though she wrote incorrectly 27/88 nouns (30.6%), 6/17 adjectives (35.2%), 16/30 verbs (53.3%) and 4/20 functors (20%), the effect of grammatical class fell short of statistical significance (chi-square = 7.046; p = between <.10 and <.05). A non-significant trend towards greater accuracy in reproducing high-frequency than low-frequency words was observed. AZO produced incorrectly 13/63 (20.6%) high-frequency words and 24/66 (36.3%) low-frequency words (chi-square = 3.168; p = between <.10 and <.05). AZO’s response accuracy to concrete words (13/50 incorrect responses, 26%), and to abstract words (13/35 incorrect responses, 37.1%) was comparable (chi-square = 0.736; p = n.s.). Length had a clear effect on performance: she responded incorrectly to 22/100 (22%) short words, to 20/38 (52.6%) intermediate words, and to 11/17 (64.7%) long words. The length effect is statistically reliable (chi-square = 19.419; p <.001). Responses to pseudowords were also affected by length. AZO’s performance significantly deteriorated from short (4/19 incorrect responses, 26.6%) to intermediate (17/19, 89.4%) and to long pseudowords (30/32, 93.7%); chisquare = 28.542; p <.001. Qualitative Analyses Qualitative analyses were restricted to single-type error responses (substitutions, or insertions, or deletions, or transpositions) and to clearly recoverable, multiple error responses (e.g., a substitution and an insertion) produced in word writing3. Incomplete responses, that occurred in responses to stimuli of 8 or more letters (6 in alphabetic writing, 4 in shorthand writing) were not considered in the analyses that follow. Four incorrect alphabetic strings and 3 incorrect shorthand strings that resulted in complex errors (e.g., spaventa, it frightens → vaperso, nonword) or in strings that did not allow an unambiguous interpretation (e.g., tranne, except → stanne, which may have resulted either from two substitutions (t → s; r → t), or from the combination of a substitution (r → s) and a transposition) were also excluded. These errors occurred to stimuli of 6 or more letters, and were never produced in response to shorter stimuli. Finally, inflectionally related responses (2 in alphabetic writing and 1 in shorthand writing) were also excluded. Thus, the 70 letters produced incorrectly in spelling 43 words in the alphabetic task and the 61 letters produced incorrectly in spelling 45 words in the shorthand writing task were retained. The distribution of error types in alphabetic writing and in shorthand writing is very similar (Table II). AZO substituted, deleted, inserted or transposed comparable numbers of letters in alphabetic and in shorthand writing. The stimulus-error relationship in letter substitutions was also analysed. In order to obtain a reliable measure, only single letter substitutions were considered. The number of substituted elements bearing a visual/motoric resemblance, a phonological resemblance, a visual/motoric and a phonological resemblance, or no resemblance to the target was evaluated. In alphabetic writing, 7/19 (36.8%) substituted letters were phonologically related to the target, 5/19 (27.2%) TABLE II

Distribution of Error Types Produced by AZO when Writing Words in the Alphabetic and in the Shorthand Code: Number of Letters Involved in Each Error Type (percentages are in parentheses) Words

Substitutions Deletions Insertions Transpositions

Alphabetic (n = 70)

Shorthand (n = 61)

35 19 10 6

38 18 3 2

(50.0) (27.1) (14.3) (8.6)

(62.3) (29.0) (4.8) (3.2)

3 AZO’s very poor performance with pseudowords offered only very limited opportunity for qualitative analyses and thus errors in writing pseudowords were excluded from these analyses.

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were motorically related, and 7/19 (36.8%) were unrelated. All the errors related only motorically to the target resulted from substituting cursive a for o, or from the reverse error. In shorthand writing, 9/32 (28.1%) substituted elements were phonologically similar to the target, 15/32 (46.9%) were visually/motorically and phonologically similar to the target, and 8/32 (25%) were unrelated. Also in this case, the distribution across codes is similar. The higher incidence of visually/motorically similar substitutions in shorthand as opposed to alphabetic writing is not surprising. In fact, in the shorthand system practiced by AZO elements corresponding to phonemically-related letters are also visually similar, as shown by the examples in Figure 1 (this is not always the case in alphabetic writing – consider cursive p and t). A further analysis focused on all the incorrect letters produced by our subject. Considering that AZO suffered from a disorder of auditory input processing (poor phoneme discrimination), and of sublexical phoneme-grapheme conversion mechanisms (massively disrupted nonword writing), the aim of this analysis was to evaluate what percentage of the incorrect letters produced by AZO might result from damage to these mechanisms. All the errors reported in Table II were considered in this analysis. Of the 35 letters substituted in alphabetic responses, 17 (48.6%) were phonologically related and 18 (51.4%) were phonologically unrelated (of these, 6 were motorically/orthographically related, 17.1%). Of the 38 letters substituted in shorthand responses, 29, or 76.3% were phonologically related (of these, 18 were both phonologically and visually/motorically related, 47.4%), and 9 were phonologically unrelated (23.7%). Of the 19 deletions observed in alphabetic writing, 5 (26.3%) consisted of the deletion of a geminate cluster, resulting in phonologically related incorrect responses (piuttosto, rather → piutosto), and the remaining 14 (73.7%) consisted of phonologically unrelated errors (perdonato, forgiven → peronato). In shorthand writing, all deletions (18/ 18, 100%) resulted in phonologically unrelated responses (turno, turn → tuno). Of the 10 insertions observed in alphabetic writing, 2 (20%) resulted in phonologically plausible errors (false, sickle → falcie), 2 (20%) in consonant gemination errors (vizio, vice → vizzio), and 6 (60%) in phonologically unrelated responses (atteso, awaited → attenso). In shorthand writing, 1/3 insertions (33.3%) resulted in a phonemically related error (brace, ashes → bracie), and 2/3 in a phonemically unrelated response (oltre, beyond → olotre). None of the transposed letters (6 in alphabetic writing, and 2 in shorthand writing) resulted in phonologically related strings. Thus, 30/70 (42.8%) of the letters produced incorrectly in interpretable responses in alphabetic writing, and 30/61 (49.2%) of the letters produced incorrectly in shorthand writing were phonologically related to the target. These errors could have resulted from a disorder of auditory input processing, or from damage to phonemegrapheme conversion mechanisms (although, at least some of them might also result from damage to other components of the spelling system). Consequently, the remaining 57.2% phonologically unrelated errors observed in alphabetic writing, and the remaining 50.8% similar errors errors observed in shorthand writing cannot be accounted for either by poor auditory input processing, or by damage to phoneme-grapheme conversion mechanisms. We have noted that AZO’s performance was significantly affected by stimulus length, independently of the code (alphabetic/shorthand) and of the lexical status of the stimulus (word/pseudoword). However, previous analyses of the length effect were based on the number of alphabetic letters in the stimulus. Thus, the results reported in Table I are reliable for alphabetic writing, but may be inaccurate for shorthand. The latter concern is motivated by the fact that alphabetic length is not perfectly correlated with length in the shorthand code4. In light of these concerns, the length effect was reconsidered by measuring the length of shorthand stimuli in terms of the symbols that comprise the shorthand spelling of a stimulus. Table III reports the length effect for alphabetic writing (first column); shorthand writing

4 The difference between alphabetic and shorthand length of words varies across a very large range. Consider the following examples. The alphabetic representation of telefono, telephone, contains 8 graphemes, and the corresponding shorthand representation contains 7 symbols, since the final letter is usually omitted in shorthand writing. In other cases, the difference in length is much greater. For example, the derived word attenzione, attention, contains 10 letters in the alphabetic code, but only 4 in the shorthand code, as -tt- is marked by reinforcing the t sign, n- by lengthening the symbol corresponding to the preceding vowel e, the derivational cluster zion- is abbreviated by producing only the z, and the final -e is omitted.

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TABLE III

Effect of Stimulus Length on Performance Accuracy in Writing Words to Dictation in the Alphabetic and in the Shorthand System. Number of Incorrect Responses (Stimulus length for shorthand stimuli corresponds to the number of alphabetic graphemic elements in the second column, and to the number of shorthand elements in the third column; percentages are in parentheses) Length 1 2 3 4 5 6 7 8 9 or more

Alphabetic

Shorthand (alphabetic length)

— — — 0/7 (0.0) 16/69 (23.1) 6/24 (25.0) 5/11 (45.4) 15/27 (55.5) 13/17 (76.5)

— — — 1/7 (14.3) 16/69 (23.1) 6/24 (25.0) 8/11 (72.7) 13/27 (48.2) 12/17 (70.6)

Shorthand (shorthand length) 0/1 6/22 10/53 14/38 15/23 5/10 3/6

(0.0) (27.2) (18.8) (36.8) (65.2) (50.0) (50.0) — —

length considered to be equal to alphabetic length (central columns); and, shorthand writing – length measured in terms of the shorthand representation (right column). A very similar length effect across alphabetic and shorthand writing is observed when an alphabetic measure of shorthand response length is used (first two columns). A different picture emerges when shorthand word length is measured as the number of elements in a shorthand representation (third column). An obvious length effect is still present (1-3 elements vs 4-7 elements: chisquare: 11.151; p <.001), but performance in alphabetic writing does not parallel performance in shorthand anymore. Unfortunately, a thorough comparison is impossible, as the number of stimuli at each length level in alphabetic and in shorthand writing differs substantially (most shorthand targets range in length between 2 and 5 elements, whereas most alphabetic responses range in length between 5 and 8 letters). Only partial comparisons are possible. With 5-element words, AZO is more accurate in alphabetic than in shorthand writing. She produces 16/69 (23.1%) incorrect alphabetic responses, and 15/23 (65.2%) incorrect shorthand responses (chi-square = 11.822; p <.001). However, when 6- and 7-element responses are considered, even though AZO still produces fewer incorrect alphabetic (11/35, 31.4%) than shorthand responses (8/16, 50%), the difference is not significant (chi-square = 0.923; p = n.s.)5.

DISCUSSION AZO was asked to write words and pseudowords to dictation in the alphabetic and in the shorthand code. Her results can be summarized as follows. Overall, performance accuracy in the two codes was comparable, for both words and nonwords. The probability that she produced two correct responses, or two incorrect responses, or a correct response and an incorrect response to the same stimulus (be it a word or a nonword) in the two codes did not differ from chance. Independent of writing code, AZO performed more accurately on words than on nonwords; and, she wrote more accurately short stimuli than long stimuli. Lexical variables (grammatical class, abstractness/concreteness, frequency) significantly

5 A completely accurate evaluation of the length effect in shorthand writing is extremely difficult. The shorthand code makes extensive use of a strategy that is equivalent to what is known in speech as coarticulation. For example, the same sign can correspond to various strings (e.g., ba, be, bi, etc.), depending on its position with respect to the base line, or to its slope. Also, letter doubling is marked by tracing with greater strength the to-be-geminated letter; and, so on. Thus, in some cases it is very hard to establish how many errors were produced or, even worse, what counts as a shorthand “letter”. In addition, whereas in alphabetic writing illegal letter sequences can be produced without producing ill-formed letters, in shorthand writing many errors, especially in the context of consonant clusters, cannot occur without resulting in ill-formed “letters”.

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affected AZO’s response accuracy to words in the alphabetic code, but did not reach significance in the shorthand code even though similar effects were observed6. The interpretation of these results is not easy. The reliable length effect (observed on words and nonwords alike, independent of writing code), the low item consistency across tasks, the fact that all incorrect responses could be scored as letter substitutions, insertions, deletions and transpositions, and, the fact that similar distributions of errors were obtained across writing systems, are consistent with the hypothesis that AZO’s writing errors result from damage to the graphemic buffer. This account runs into several problems, however. A major problem in attributing AZO’s errors to graphemic buffer damage results from her superior performance on word writing as opposed to nonword writing. In previously reported cases (e.g., Caramazza et al., 1987; Jonsdottir et al., 1995; Kay and Hanley, 1994; McCloskey et al., 1994; Miceli et al., l995; Posteraro et al., 1989) a small advantage for words, in the context of normal results on auditory processing tasks and of the absence of lexical effects in spelling, has been interpreted as not being inconsistent with damage to the graphemic buffer. However, the presence of lexical effects in AZO’s spelling indicates that damage to other components of the spelling process besides the buffer is implicated in her performance. For example, there is evidence of damage to the output lexicon (poor performance on written naming; frequency effects in writing to dictation). In addition, her ability to process auditory input is impaired (poor phoneme discrimination), raising the possibility that a number of her spelling errors may have resulted from failure to normally recognize the auditory stimuli. In this context, it is reasonable to assume that, when asked to write to dictation a low-frequency word, AZO on occasion failed to recognize the word and thus attempted to write the stimulus through sub-lexical phonology-orthography conversion processes (consistent with this possibility, 2/55 incorrect responses in alphabetic spelling (3.6%) and 1/53 in shorthand spelling (1.9%) resulted in phonologically-plausible errors, like falce, sickle → falcie). However, reliance on the sub-lexical conversion procedure would have resulted in inaccurate responses, since the input string was poorly analyzed as a consequence of her auditory processing deficit. Hence, the advantage for words over pseudowords may be the result of inadequate auditory processing of unfamiliar auditory sequences. Consistent with this account (and with the hypothesis that our subject also suffers from damage to sublexical phoneme-grapheme conversion procedures) are several qualitative aspects of spelling performance, such as the fact that almost half of the letters involved in substitutions, deletions and insertions, in both alphabetic and shorthand writing were phonologically related to the target. An additional problem in interpreting AZO’s spelling performance is that many of her errors could result from damage to components other than the graphemic buffer. For one thing, her performance was sensitive to lexical variables. In this context, comparable performance across codes could be an artifact resulting from lexical damage, rather than the consequence of damage to the graphemic buffer. This interpretation is unlikely, however. The analysis of AZO’s performance on word writing across codes demonstrated that 75/155 stimuli (48.4%) were consistently spelled correctly, and that at least an incorrect response was observed on the remaining 80/155 (51.6%). Our subject produced an incorrect shorthand response to 25/155 stimuli (16.%) and an incorrect alphabetic response to 24/155 (15.5%); and, she consistently spelled incorrectly 31/155 stimuli (20%). Therefore, only 31/80 words (38.7%) resulted in errors in both alphabetic and shorthand writing. Even if it is assumed

6

The occurrence of significant lexical effects (e g, a concreteness effect) in alphabetic writing, but not in shorthand writing, might be taken to suggest that AZO suffered from damage to alphabetic lexical representations, but not to shorthand lexical representations. A possible, intriguing explanation for this discrepancy would be that the alphabetic and the shorthand lexical representations for the same word are independent, and that AZO suffers from more severe impairment of lexical alphabetic than of lexical shorthand representations. (Interestingly, this pattern is consistent with a related observation in a brain-damaged stenographer described by Regard, Landis & Hess (1985), who presented with pure alexia for print, but not for shorthand). However, we are reluctant to treat these differences as suggesting differential impairment of alphabetic, as opposed to shorthand, lexical representations. In the first place, the corpus considered for analysis is rather small. Secondly, our word lists were constructed on the basis of normative data for alphabetic words. Since corresponding counts for shorthand words are not available, frequency and length (both of which affected AZO’s performance) may have interacted differently in shorthand as opposed to alphabetic writing. Thus, we prefer to conservatively interpret the data on alphabetic and shorthand word writing as suggesting damage to orthographic representations in both codes, without further implications.

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that all the consistently incorrect responses resulted from lexical damage, the number of words that yielded an incorrect alphabetic response and an incorrect shorthand response is still rather small, and the lexical items that contribute to AZO’s spelling errors are for the most part different across the alphabetic and the shorthand code. Thus, it is not clear how a putative lexical effect would result in similar writing performance in the two codes. Therefore, even though we cannot confidently adjudicate each error to a lexical or to a graphemic buffer source, the available results allow us to infer that AZO (also) suffers from damage to the graphemic buffer. And, of course, the assumption of damage to the graphemic buffer does not rule out the possibility that such damage interacts with other variables. For example, buffer damage and lexical damage could interact, thus resulting in different (greater or smaller) effects for different types of words. To sum up, it is evident that AZO suffers from a complex cognitive impairment, that involves at least auditory input processing, phoneme-grapheme conversion procedures and the orthographic output lexicon. Each of these components may contribute to incorrect performance in both alphabetic and shorthand writing. Some aspects of AZO’s spelling performance, however, cannot result from deficits other than graphemic buffer damage. 1) Clear transposition errors were observed in alphabetic as well as in shorthand writing, but not in speaking. Transposed letters did not occur often in simple-type errors, but they were very frequent in the context of complex errors or fragmented responses not considered for the reported qualitative analyses (consider incorrect alphabetic nonword strings like rango, rank → grant, nonword; crisi, crisis → risri; and incorrect shorthand nonword strings like telefona he phones → telofanr; doloroso, painful → dorol...; disordine, disorder → disconid). It is not clear how damage to sub-lexical conversion processes could result in transposition errors. 2) AZO made the same error types in all writing tasks, independent of whether or not they involved an auditory input. For example, letter substitutions, deletions and transpositions were observed not only in writing to dictation, but also in written picture naming and in spontaneous writing. 3) A significant length effect was observed in all writing tasks. When the 110 content words produced in the alphabetic code in the course of written picture naming, of written picture description and of spontaneous written narratives were considered, errors were observed on 6/66 (9.1%) words of 4-6 letters, on 5/28 (17.6%) words of 7-8 letters, and on 7/16 (43.7%) words of 9 or more letters (chisquare = 21.68; p <.001). 4) In shorthand writing, the grapheme < r > in a context (as in parto, delivery) does not correspond to an autonomous symbol, and is indicated by lengthening the preceding vowel and reinforcing the following consonant. Of the 30 contexts in the corpus administered to AZO, there were 7 instances (23.3%) in which AZO failed both to lengthen the vowel and to reinforce the consonant. These errors can only arise at an orthographic, not at a phonological locus, since the missing information is strictly orthographic in nature – had the subject made a phonological error she would have produced some other symbol and not an orthographic distortion. Thus, the facts in 14 allow the conclusion that at least part of AZO’s difficulties in alphabetic and in shorthand writing result from damage to the graphemic buffer. Published reports on dual-code writing systems are consistent with the view that information specific to each code is represented independently. Thus, there have been cases of dysgraphia in Japanese, in which kana or kanji were selectively disrupted by brain damage (e.g., Iwata, 1986; Kawamura et al., 1987, 1989; Mochizuki and Ohtomo, 1988; Soma et al., 1989; Tanaka et al., 1987; Tei et al., 1994; Yamadori et al., 1980; Yokota et al., 1990). The results reported here were also obtained with a subject who was skilled in the use of two codes (alphabetic and shorthand Italian). Her performance was very similar in the two codes. Qualitative and quantitative analyses show that at least part of her errors result from damage to the graphemic buffer. These results indicate that in multiple-code writers (e.g., stenographers, but also speakers of languages like Japanese, or multilingual speakers of languages that use different spelling codes), a common graphemic buffer is shared by all codes in the process of spelling. Acknowledgements. The research reported here was supported in part by PHS Research Grant 7 R01 NS22201-11 to Alfonso Caramazza, and by grants from CNR, Ministero della Sanità and MURST to Gabriele Miceli. The authors wish to express their gratitude to AZO for her collaboration.

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BROWN, G.D.A., and LOOSEMORE, R.P.W. Computational approaches to normal and impaired spelling. In G.D.A. Brown and N.C. Ellis (Eds.), Handbook of Spelling: Theory, Processing and Intervention. Chichester: John Wiley & Sons, 1994. CARAMAZZA, A., MICELI, G., VILLA, G., and ROMANI, C. The role of the graphemic buffer in spelling: Evidence from a case of acquired dysgraphia. Cognixion, 26: 59-85, 1987. ELLIS, A.W. Spelling and writing (and reading and speaking). In A.W. Ellis (Ed.), Normality and Pathology in Cognitive Functions. New York: Academic Press, 1982. HILLIS, A.E., and CARAMAZZA, A. The graphemic buffer and attentional mechanisms. Brain and Language, 36: 208-235, 1989. IWATA, M. Neural mechanisms of reading and writing in the Japanese language. Functional Neurology, 1: 43-52, 1986. JONSDOTTIR, M., SHALLICE, T., and WISE, R. Language-specific differences in graphemic buffer disorder. Cognition, 1995. KAY J., and HANLEY, R. Peripheral disorders of spelling: The role of the graphemic buffer. In G.D.A. Brown and N.C. Ellis (Eds.), Handbook of Spelling: Theory, Processing and Intervention. Chichester: John Wiley, 1994, pp. 295-315. KAWAMURA M., HIRAYAMA K., HASEGAWA K., TAKAHASHI N., and YAMAMURA A. Alexia with agraphia of kanji (Japanese morphograms). Journal of Neurology, Neurosurgery and Psychiatry, 50: 11251129, 1987. KAWAMURA, M., HIRAYAMA, H., and YAMAMOTO, K. Different intrahemispheric transfer of kanji and kana writing evidenced by a case with left unilateral agraphia without apraxia. Brain, 112: 10111018, 1989. MCCLOSKEY, M., BADECKER, W., GOODMAN-SHULMAN, R.A., and ALIMINOSA, D. The structure of orthographic representations in spelling: Evidence from a case of acquired dysgraphia. Cognitive Neuropsychology, 11: 341-392, 1994. MICELI, G., BENVEGN U` , B., CAPASSO, R., CARAMAZZA, A. Selective deficit in processing double letters. Cortex, 31: 161-171, 1995. MICELI, G., LAUDANNA, A., BURANI, C., and CAPASSO, R. Batteria per l’Analisi dei Deficit Afasici. Roma: CEPSAG, 1994. MOCHIZUKI, H., and OHTOMO, R. Pure alexia in Japanese and agraphia without alexia in kanji. The ability dissociation between reading and writing in kanji vs kana. Archives of Neurology, 45: 11571159, 1988. OLSON, A., and CARAMAZZA, A. Representation and connectionist models: The NETspell experience. In G.D.A. Brown and N.C. Ellis (Eds.), Handbook of Spelling: Theory, Processing and Intervention. Chichester: John Wiley & Sons, 1994. POSTERARO, L., ZINELLI, P., and MAZZUCCHI, A. Selective impairment of the graphemic buffer in acquired dysgraphia: A case study. Brain and Language, 35: 274-286, 1988. REGARD, M., LANDIS, T., and HESS, K. Preserved stenography reading in a patient with pure alexia. Archives of Neurology, 42: 400-402, 1985. SOMA, Y., SUGISHITA, M., KITAMURA, K., MARIYAMA, S., and IMANAGA, H. Lexical agraphia in the Japanese language. Pure agraphia for kanji due to left posteroinferior temporal lesions. Brain, 112: 1549-1561, 1989. TANAKA, Y., YAMADORI, A., and MURATA, S. Selective kana agraphia: A case report. Cortex, 23: 679684, 1987. TEI, H., SOMA, Y., and MARIYAMA, S. Right unilateral agraphia following callosal infarction in a lefthander. European Neurology, 34: 168-172, 1994. YAMADORI, A., OSUMI, Y., IKEDA, H., and KANAZAWA, Y. Left unilateral agraphia and tactile anomia. Disturbances seen after occlusion of the anterior cerebral artery. Archives of Neurology, 37: 8891, 1980. YOKOTA, T., ISHIAI, S., FURUKAWA, T., and TSUGAKOSHI, H. Pure agraphia of kanji due to thrombosis of the Labbé vein. Journal of Neurology Neurosurgery and Psychiatry, 53: 335-338, 1990. Gabriele Miceli, Neurologia, Università Cattolica del Sacro Cuore, Largo A. Gemelli 8, 00168 Roma, Italy. e-mail: [email protected] Alfonso Caramazza, Cognitive Neuropsychology Laboratory, Department of Psychology, Harvard University, William James Hall, 33 Kirkland Street Cambridge, MA 02138, U.S.A. e-mail: [email protected]

(Received 1 December 1995; accepted 26 November 1996)

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APPENDIX In the shorthand writing system used by AZO, vowels and consonants correspond to symbols, as if they were letters of the alphabet. Consonants are indicated by symbols oriented downward, and vowels by horizontal signs, or by upward going symbols. Since the main purpose of the shorthand system is the on-line mapping of an auditory string into a written string, the choice of symbols is influenced by their phonetic/phonemic value – similar sounds correspond to similar signs; in addition, sounds with the highest frequency of occurrence correspond to “easy-to-trace” signs, and sounds with a low frequency of occurrence correspond to “hard-to-trace” signs. A word written in shorthand usually contains fewer symbols than the same word written alphabetically, because of a systematic pattern of abbreviations. A. Some abbreviations result more or less directly from phonetic or phonemic features. For example: 1. a nasal consonant followed by another consonant is indicated by lengthening the sign corresponding to the preceeding vowel; 2. geminate letters are indicated by tracing with greater strength (reinforcing) the sign corresponding to the to-be-geminated consonant. B. Some abbreviations apply over segments that are best described as very frequent sequences of letters. For example: 1. the sequence PER- in initial position is converted into the sign corresponding to just P when followed by a downgoing sign; 2. the sequence PRin word-initial position is marked by a dot added above or below the following vowel. C. Some abbreviations apply over morphologically-defined units. For example, letter sequences that correspond to derivations. (-EVOL-, -GRAFI-, -TUDIN-, -MENT-, -ZION-, -ISSIM-, etc.) or to inflections (-AV-, -EV-, -IV-, -REBBE, -REBBERO, etc.) are often written in shorthand by reducing them to just one or two symbols. However, the same abbreviations also apply when the same letter sequences appear in a non-morphological context. For example, the sequence -EVOL- (that usually functions as a derivation, roughly corresponding to the English -ABLE and -IBLE), is converted into the symbol of stressed E followed by L, both in a derived word like GIREVOLE (that can be turned), and in a non-derived word like FIEVOLE (feeble). D. Some words (especially words of very high frequency, such as free-standing grammatical morphemes) are written by means of very simple “logograms”. E. Some letters or letter sequences are systematically omitted. Omissions involve euphonic letters (e.g., letter D in the conjunctions ED and OD), letter C in the cluster -CQU- (ACQUA), letter H in exclamations (AH!) and in borrowed words (SQUASH). Omissions also involve final vowels and diphtongs, provided that no ambiguities arise, and some verb inflections (infinitive, past participle, plural inflection if recoverable from context). Thus, in some cases omissions involve units that can be best defined as letters, whereas in others the material that is omitted corresponds to a morphological unit. F. In Italian, some phonemes correspond to sequences of more than one letter. In shorthand writing, the correspondence is simplified so that one phoneme corresponds to one symbol. For example, the 2-phoneme sequence /ʃe/ in /ʃentza/ (science) corresponds to the 4-letter alphabetic sequence SCIENZA. In shorthand writing, just two symbols are used, one for / ʃ/, and one for /e/. Also, on rare occasions in Italian the same sound corresponds to one of two alphabetic sequences. For example, /k/ in /’kave/ (caves) corresponds to CAVE, whereas /k/ in /’kyave/ (key) corresponds to CHIAVE. The same shorthand symbol is used in these cases. This rule, however, does not apply across the board. For example, initial /k/ can correspond to Q, as in /’kwota/ → QUOTA (quote), or to C, as in /’kwore/ → CUORE (heart). In this case, shorthand preserves the orthographic distinction by reinforcing the U in QUOTA, but not in CUORE.