ALEXIA FOR IDEOGRAMS: IMPLICATIONS FOR KANJI ALEXIA

Nils R. V amey

(Veterans Administration Medical Center, Iowa City, Iowa)

INTRODUCTION

In the Japanese language, there are two distinct types of writing; kanji, which are individual ideograms, and kana, which involve phonologic symbols of syllabic length. A number of cases have been reported of Japanese aphasics who developed a severe alexia for kana, but were relatively unimpaired in kanji reading ( cf. Sasanuma, 1975, 1980). There is a second, far rarer phenomenon known as Gogi aphasia in which oral reading of kanji is impaired while oral reading of kana is intact (Imura, 1943; Sasanuma and Nonoi, 1975). However, Gogi aphasics are severely impaired in reading comprehension of both kanji and kana, and there have been no reported cases in which comprehension of kanji was impaired while comprehension of kana was preserved. Thus, it is possible to be impaired in kana reading while retaining normal kanji reading, but all aphasics with defects in reading comprehension of kanji are also impaired in kana reading.

The purpose of the present study was to develop and test a model for kanji reading which would be suitable for use with non-Japanese aphasics. The specific rationale and methods for this are presented below.

MATERIALS AND METHOD

Subjects

Three groups of subjects were involved in the study; 70 with left brain lesions and aphasia, 30 with right brain lesions who were not aphasic, and 30 normal con trois. All were right handed, had at least an 8th grade education, were between 35 and 70 years of age, and had no history of psychiatric illness. All of the brain injured patients had suffered a single CV A between two and six weeks prior to being evaluated. The presence of a brain lesion was determined on the basis of clinical neurologic examination and the results of CT scan. Control subjects were all hospital inpatients at the time and had no history of neurologic disease.

Cortex (1984) 20, 535-542

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Ideogram Reading

Nils R. Varney

Tests and Procedure

The ideograms selected for use in this study were animal footprints. A sample item from the task is shown in Figure 1. On each of the test's 18 items, the patient was shown a line drawing of an animal, below which were four examples of footprints. The patient was required to identify the footprints appropriate for the animal shown.

Footprints are like kanji writing in that they are individual symbols consisting of lines and curves which must be perceptually discriminated, recognized as being familiar, and associated with a correct meaning (i.e., the animal producing the print). Unlike Western writing and kana, kanji and footprints involve no phon­ologic decoding. The footprint ideograms are, of course, much less perceptually and semantically complex than kanji, require no formal education to be familiar, and are far less numerous than the thousands of kanji sumbols in Japanese. Nevertheless, it appeared reasonable to presume that the foorprint ideograms represented a rudimentary type of kanji-like writing, with the symbols being clearly "readable" for non-Japanese.

0 00 \] ~0 ))] n

Fig. 1 - Sample test items.

Word Reading

The reading comprehension subtest from the Multilingual Aphasia Exami­nation (Benton and Hamsher, 1979) was used to evaluate word reading. In this test, subjects are shown words printed in one inch bold type and are required to

Alexia for ideograms 537

point to a drawing of the object or activity named from among four choices. There are 18 items on the test. Based on previously established norms, scores of 15 correct and below are classified as defective (i.e., below the 5th percentile).

Letter Recognition

In this test, subjects are required to match upper and lower case letters of the alphabet which have different shapes between cases (e.g., A and a, or d and D, but not o and 0). On each of 20 test trials, the subject is shown three letters and is required to identify the two which are the same. Based on previously established norms ( cf. Varney, 1981 ), scores of 16 correct and below are classified as defective (i.e., below the 1st percentile).

Pantomime Recognition

This test (Benton et al., 1983) requires subjects to identify objects whose pretended use is shown in 30 videotaped pantomimes. On each test trial, subjects chose from among four response alternatives. Based on previously established norms, scores of 25 and below are classified as defective (i.e., below the 5th percentile). This test also includes an error foil on each test trial which is semantically related to the correct choice (e.g., axe and saw, pen and typewriter). Among aphasics with defects in pantomime recognition, semantic errors are typically far more common than other types of errors (cf. Varney and Benton, 1982).

Visual Form Discrimination

The 16 items on this test of Benton et al. (1983) are complex geometric figures. On each test trial, the subject is shown one of these figures and is asked to identify an identically shaped figure from among four choices. Defective performance on this task has been shown to be very common among aphasics with defects in letter recognition (cf. Varney, 1981).

RESULTS

Among the 30 control subjects, footprint reading scores ranged from 18 to 15 correct, with the latter score being obtained from two subjects. Performances below 15 correct were classified as defective. Among the 30 right brain damaged patients, footprint reading scores ranged from 18 to 16 correct, all being within normal limits. Scores of the 70 aphasic subjects ranged from 18 to 4 correct, with 17 individuals (24%) obtaining defective scores from 14 to 4 correct. Thirty-three aphasics (47%) were impaired in reading comprehension, 13 ( 19%) were impaired in letter recognition, and 13 (19%) were impaired in pantomime recognition. All of the control and right brain damaged patients performed normally in reading comprehen­sion, letter recognition and pantomime recognition. The performances of aphasics with defects in footprint reading are shown in Table I.

538 Nils R. Varney

TABLE I

Test Scores of Patients with Defects in Footprint Reading

Footprint Reading

9 9

11 13 6 9 9

14 4 6 8 9 9 9

10 11 12

Word Reading

4 4 7 8 7 4 4

12 4 4 4 4 4 4 6 5 8

* = Denotes intact test performance. * * = The case which resembled Gogi aphasia.

Letter Recognition

12 15 13 13 19* 17* 17* 19* 8

11 13 11 12 13 13 15 14

Footprint and Word Reading

Pantomime Recognition

28* .27* 26* 26* 13** 22 16 23

9 17 11 16 11 11 17 16 23

All of the aphasics with defective scores on the footprint test were also impaired in reading comprehension. Their best reading score, obtained from a patient with a footprint score of 14 correct, was 12. The remaining scores were all in the severely alexic range (i.e., less than 50% correct responses) and nine were totally alexic. There were, however, another five severely alexic patients who performed normally in footprint reading. Thus, while all aphasics with impaired "kanji" reading were also impaired in word reading, nearly half of the alexic subjects performed normally in footprint reading.

Footprint Reading and Letter Recognition

Among the aphasics with defects in footprint reading, 13 (76%) were also impaired in letter recognition. In addition, all of the aphasics with defects in letter recognition were impaired in footprint reading, with scores ranging from 11 to 4 correct (i.e., severely impaired). In addition, all of the aphasics with letter recognition defects were impaired in visual form discrimination. This was not true of the remaining three aphasics with impaired footprint reading. However, there were an additional 9

Alexia for ideograms 539

aphasics involved in the study who failed the visual form discrimination test. It would appear, therefore, that all aphasics with defects in letter recognition were also impaired in footprint reading and visual form discrimination, but that defects in footprint reading or visual form dis­crimination could occur without defects in letter recognition.

Footprint Reading and Pantomime Recognition

There were 13 aphasics with defects in footprint reading who were also impaired in pantomime recognition, and all of the aphasics with defects in pantomime recognition were also impaired in footprint reading. It should also be noted that all aphasics with defects in footprint reading were either impaired in letter recognition, pantomime recognition, or both. Thus, the remaining 53% of reading impaired aphasics performed normally in footprint reading, letter recognition, and pantomime recognition.

A Case Resembling Gogi Aphasia

One aphasic patient (see Table I) appeared to have a reading disorder which was similar to Gogi aphasia. Its most relevant features were ( 1) oral reading was correct for 17 of the 18 test stimuli on our reading compre­hension test, but comprehension was correct for only 7 items, (2) footprint reading comprehension was impaired, (3) letter naming was severely impaired, but letter recognition was nearly errorless. Thus, he showed intact oral reading of kana like words with generally impaired reading comprehension, including our "kanji", and impaired letter naming (which has some features in common with oral kanji reading).

Additional features of note in this patient include that he was severely impaired in pantomime recognition and aural comprehension, was incap­able of writing and drawing, and produced frequent semantic paraphasias and neologisms in naming, spontaneous speech and repetition. CT scan indicated a high parietal vascular lesion of the left hemisphere. Autopsy indicated a 1.5 em wide, 6 em long lesion extending downward in the left parietal lobe.

DISCUSSION

These findings on the relationship between ideogram reading and word reading are quite similar to those reported with regard to kanji in the following respects. First, all aphasics with defects in ideogram reading

540 Nils R. Varney

were also impaired in word reading just as all Japanese aphasics with defects in kanji are also impaired in kana. Second, some aphasics with defects in word reading performed normally in ideogram reading just as some with impaired kana reading can retain normal kanji. Third, a case similar to Gogi aphasia was observed in which reading comprehension of ideogram and words was impaired, but oral reading of words was intact (i.e., hyperlexia). Fourth, no defects in ideogram reading were observed among left brain injured patients with normal word reading or among non-aphasics with right sided lesions. In these respects, therefore, our model of kanji reading would appear reasonable.

Where our model would appear to differ from true kanji is with regard to the frequency with which word reading was impaired while ideogram reading was normal. This pattern was observed in one-third of our reading impaired patients. It is likely that this finding reflects the relatively ele­mentary nature of the ideogram stimuli employed as compared to true kanji, of which there are thousands of symbols. Thus, the "kanji alexia" observed in our population most probably corresponds to the more severe forms of kanji alexia in Japanese.

Among aphasics with defects in ideogram reading, 76% were impaired in letter recognition. More importantly, all aphasics with defects in letter recognition were also impaired in ideogram reading. As has been reported previously, all of the aphasics with defects in letter recognition were also impaired in visual discrimination of geometric shapes (Varney, 1981 ). These findings suggest that all defects in letter recognition and some defects in ideogram reading reflect, at least in part, disturbance in the perceptual discrimination of letter/ideogram shapes. It can be inferred, therefore, that a significant proportion of kanji alexias also reflect problems with discrimination of linear and curvilinear sti­muli. However, it should also be noted that some aphasics with defects in ideogram reading were not impaired in letter recognition or visual form discrimination, one of which was the "Gogi aphasic" mentioned above.

Assessment of pantomime recognition was included as part of the study because defects in pantomime recognition have been found to be consistently associated with defects in reading comprehension (Varney, 1978, 1982), and because disturbances in pantomime recognition appear to reflect a relatively specific disturbance in extracting correct meaning from visual communications (Varney and Benton, 1982). As expected, all aphasics with defects in pantomime recognition were also impaired in ideogram reading. In addition, the "Gogi aphasic" was impaired in pan­tomime recognition, but not letter recognition/form perception, which helps explain the nature of his symptom pattern and preserved oral reading.

Alexia for ideograms 541

In combination, these findings suggest that there are two distinct determinants of ideogram alexia and kanji alexia. In one variety, the defect reflects problems with perceptual discrimination of letters and letter-like shapes such as ideograms and kanji stimuli. In the other variety, the defect reflects problems with the association of clearly perceived stimuli with correct meaning. Neither of these disabilities is specifically relevant only to ideograms or kanji because each affects other related visually mediated abilities. That this should be the case is not surprising given the fact that the evolution of the visual system was entirely complete prior to the cultural development of reading and writing in any culture ( cf. Varney and Vilensky, 1980).

ABSTRACT

This study was concerned with a model for kanji reading applicable in a non-Japanese population of aphasics. The experimental task required aphasic subjects to match animals with their footprints, a type of ideogram "reading" requiring no special training. As is true for kanji, footprint reading defects were consistently associated with word reading impairment, but some aphasics with defects in word reading performed normally in footprint reading. All with defects in footprint reading were also impaired in letter recognition or pantomime recognition. One aphasic's pattern of symptoms was quite similar to the rare phenomenon of Gogi aphasia. Implications for kanji alexia are discussed.

Acknowledgements. The author would like to thank Drs. A.L. Benton, K. Hamsher, J. Marchman, R. Roberts, S. Sasanuma, and 0. Seines for their valu­able suggestions and criticisms.

REFERENCES

BENTON, A.L., HAMSHER, K., VARNEY, N.R., and SPREEN, 0. Contributions to Neuro­psychological Assessment. New York: Oxford University Press, 1983.

IMURA, T. Aphasia: characteristic symptoms in Japanese. Psychiatria et Neurologia Japonica, 47: 196-218, 1943.

SASANUMA, S. Kana and kanji processing in Japanese aphasics. Brain and Language, 2: 369-383, 1975.

SASANUMA, S. Acquired alexia in Japanese. In M. Coltheart, K. Patterson and J. Marshall (Eds.) Deep Dyslexia. London: Routledge and Kegan Paul, 1980, Ch. 3, pp. 49-90.

SASANUMA, S., and FUJIMURA, 0. Selective impairment of phonetic and non-phonetic transcription of words in Japanese aphisoc patients. Cortex, 7: 1-18, 1974.

SASANUMA, S., and MoNOI, H. The syndrome of Gogi (word meaning) aphasia. Neurology, 25: 627-632, 1975.

VARNEY, N.R. Linguistic correlates of pantomime recognition defect in aphasia. Journal of Neurology- Neurosurgery and Psychiatry, 41: 564-568, 1978.

VARNEY, N.R. Letter recognition and visual form discrimination in aphasia. Neuropsy­chologia, 19: 795-800, 1981.

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VARNEY, N.R. Pantomime recognition defect in aphasia. Brain and Language, 15: 32-39, 1982.

VARNEY, N.R., and BENTON, A.L. Qualitative aspects of pantomime recognition defect in aphasia. Brain and Cognition, 1: 132-139, 1982.

VARNEY, N.R., and VILENSKY, J. Neuropsychological implications for preadptation and language evolution. Journal of Human Evolution, 9: 223-226, 1980.

Nils R. Varney, Ph. D., Psychology Service (116B), Veterans Administration Medical Center, Iowa City, lA 52240, U.S.A.