Comprehension of symbolic gestures in aphasia

BRAIN

AND

LANGUAGE

3, 451-460

Comprehension GUIDO Clinic

for

(1976)

of Symbolic

GAINOTTI Nervous

Gestures

in Aphasia

AND MARIA ASSUNTA LEMMO

and Men&l

Diseases,

Cutholic

University,

Rome

One-hundred-and-twenty-eight patients with unilateral hemispheric damage (53 aphasics, 26 nonaphasic left, and 49 right brain-damaged patients) and 25 normal controls were given a test of symbolic gesture comprehension and other tests of verbal comprehension and of reproduction of symbolic gestures. On the test of symbolic gesture interpretation aphasic patients performed significantly worse than any other group of brain-damaged patients. Within the aphasic patients the inability to understand the meaning of symbolic gestures was highly related to the number of semantic errors obtained at a verbal comprehension test. On the contrary, only a mild relationship was found between comprehension and reproduction of symbolic gestures. Some implications of these findings are discussed.

In 1870 Finkelnburg advanced the view that aphasia was only an aspect of “asymbolia,” considered as a generalized disturbance in the capacity to express and comprehend symbols in any modality. Subsequent authors (Head, 1926; Goldstein, 1948) have followed Finkelnburg’s line of thought, considering nonverbal disorders of aphasic patients as part of a central communication disorder, but many otherwriters have discussed nonverbal defects of aphasic patients in a different sense, treating them as agnosic, apraxic, or intellectual disorders. In recent years, an important group of neuropsychological studies has given some support to the hypothesis of a symbolic disorder of aphasic patients not limited to the verbal comprehension and expression, but also evident in many nonverbal recognition tasks. Spinnler and Vignolo (1969) have shown, for example, that aphasic patients, although not impaired in tasks of subtle auditory discrimination, find it difficult to associate a meaningful sound to the corresponding picture, and De Renzi, Scotti, and Spinnler (1969) have demonstrated that aphasics are also impaired in semantic tasks of visual recognition. Results consistent with these views were obtained by Gainotti and Ibba (1972), who showed that gesture comprehension disturbances were often found in aphasic patients, and that they seemed closely related to the degree of the verbal communication disorder. However, results obtained in this last research could be biased by the fact that, although any type of verbal or nonverbal response was accepted by the examiner, patients tended generally to explain verbally the meaning of the pantomimes. It is therefore possible that the bad results Address Universiti

requests for reprintsto Guido Cattolica, Largo A. Gemelli,

Gainotti, Clinica 8-00168-Roma, 451

CopyrIght 0 1976 hy Academx Presc. Inc All rlphrs of reproduction m any form reserved.

delle

Malattie Italy.

Nervose

e Mentali,

452

GAINOTTI

AND LEMMO

obtained by the aphasic patients were due not so much to a gesture comprehension disturbance as to a language expression impairment. The main purpose of the present research was, therefore, to verify the results of the previous inquiry by means of a nonverbal multiple choice test, which could allow patients to avoid the necessity of a verbal response. A second aim of the present study was to check another finding of the previous investigation. Gainotti and Ibba (1972) had shown that gesture comprehension disturbances are markedly related to the difficulty involved in repeating the pantomimed gestures, and had suggested that difficulties in reproducing symbolic gestures, commonly attributed to ideomotor apraxia, could sometimes be the result of inability to understand the meaning of the gesture itself. Most of our patients received, therefore, besides the test of symbolic gestures comprehension, a standard test of ideomotor apraxia, currently in use in our clinic. Results obtained on the tests of interpreting pantomimes and of reproducing symbolic gestures were submitted to a correlative analysis. MATERIAL

AND METHODS

Subjects The test of symbolic gesture interpretation was administered to 25 normal controls and to 128 patients with monohemispheric cerebral lesions (53 aphasics, 49 right hemisphere, and 26 left hemisphere nonaphasic patients). All the patients had been admitted to the Clinic for Nervous and Mental Diseases of the Catholic University of Rome during a period of 20 months (from March 1973 to November 1974). Control subjects suffered either from psychoneuroses or from neurological diseases not involving the central nervous system above the level of the cervical spine. Brain-damaged patients were unselected; only subjects with clinical signs or past history pointing to bilateral hemispheric damage, left-handed subjects, and patients unable to maintain the set necessary for carrying out the task were excluded. Diagnosis of the affected side was made on the basis of the clinical findings, supplemented by the available EEG, brain-scan and neuroradiological data. Among the left brain-damaged patients the presence of an aphasic disorder was assessed by means of a standard test of aphasia, currently in use in our clinic. No significant differences were found between normal controls and either of the three groups of brain-damaged patients in relation to age and educational level.

Des trip tion of Tests Test of symbolic gesture interpretation. Twelve symbolic gestures, consisting of three commonly used, conventionalized communicative movements (for example, making the sign of the cross) and of nine simple pantomimes, intended as direct representation of actions with objects (for example, playing the guitar) were used in this test. The first two items were used as an introductory screening procedure, while the other 10 items constituted the test proper. In each case the examiner pantomimed expressively the symbolic gesture before the patient, then gave him a card containing three simple figures and asked him to point to the object specifically related to the pantomime. In each card one figure reproduced an object specifically linked to the pantomime (e.g., in Fig. 1, the guitar for the gesture of playing the guitar), while the other two figures represented either objects nonspecifically related to the symbolic gesture, but having with it some associative linkages (e.g., in Fig. 1, the trumpet) or

SYMBOLIC

FIG.

GESTURES

IN APHASIA

453

1. An item of the test of symbolic gestures interpretation.

objects quite unrelated to the pantomime (e.g., in Fig. 1, the bird). In order to avoid errors due not so much to a disturbance in gesture comprehension, but to a defect in spatial exploration, and chiefly to unilateral spatial neglect (Gainotti and Tiacci, 1971), the three figures were always arranged in a vertical array, as shown in Fig. 1. Table I reports the symbolic gestures used in the various items of the test, and the figures reproduced in the corresponding cards. The score of one point was assigned to each correct answer, so as to obtain a maximum score of 10 points. Test of ideomoror apruxia. The test of ideomotor apraxia used in the present research consisted of eight symbolic gestures (commonly used, conventionalized communicative movements). Nonsymbolic gestures had been discarded because our main purpose consisted of studying the relationships between execution and comprehension of symbolic gestures. For each item, the examiner initially gave verbal instructions. Afterwards, if the patient had not understood verbal commands or, in any case, if he had not performed in a satisfactory manner, the examiner acted out the gesture and asked the patient to reproduce it as well as he could. One point was assigned for each gesture correctly accomplished, either on verbal command or after demonstration by the examiner. The maximum score was, therefore, 8 points.

454

GAINOTTI

AND LEMMO TABLE

TASK PROTOCOL USEDFORTHE

TESTOF

1 SYMBOLIC

GESTURE

INTERPRETATION

Figures reported on the card

Symbolic gesture

Figure specifically related to the gesture

Other figures

I. Items used as an introductory screening procedure A. To make the sign of the cross B. To smoke

Priest Cigarette

Soldier Pear

Foot-bailer Pistol

II. Actual test 1. To be hungry 2. To uncork a bottle 3. To fire a pistol shot 4. To kiss 5. TO salute in a soldierlike manner 6. To drink 7. To brush one’s teeth 8. To play the guitar 9. To look through binoculars 10. To comb one’s hair

Cook Bottle Pistol Lips Soldier Glass Toothbrush Guitar Binoculars Comb

Glass Teapot Knife Trumpet Priest Plate Comb Trumpet Train Toothbrush

Trumpet Chair Fish Telephone Foot-baller Bell Revolver Bird Flower Table

The “verbal sound and meaning discrimination test”. In a previous paper (Gainotti, Caltagirone, & Ibba, 1975) we have described a test of verbal auditory comprehension, constructed with the aim of testing at the same time both the phonemic and the semantic aspects of the auditory perception of verbal sounds. The test has proved to be particularly useful for evaluating the degree of semantic disintegration in aphasia, since at the expressive level semantic impairment is often masked by other aphasic disturbances (such as a syndrome of phonetic disintegration or a phonemic jargon). Therefore, the test afforded us the opportunity of studying the relationship between the verbal and the nonverbal aspect of semantic disintegration in aphasia. The number of “semantic errors” made on the verbal comprehension test was used as an index of the verbal semantic impairment, whereas the number of errors obtainedon the test of symbolic gestures interpretation was taken as an index of nonverbal semantic disintegration.

RESULTS

Scores Obtained

on the Test of Symbolic

Gesture Comprehension

Scores obtained on the test of symbolic gesture interpretation by normal controls and by hemisphere-damaged patients are reported in Table 2. The performances of the control subjects were used to determine to what extent an imperfect performance of the brain-damaged patients could still be considered to fall within normal limits. Since only one normal control had made one error on the test of pantomime interpretation, the score of 10

SYMBOLIC

GESTURES TABLE

IN

455

APHASIA

2

SCORES OBTAINED ON THE TEST OF SYMBOLK GESTURE INTERPRETATION BY NORMAL CONTROLS AND BRAIN-DAMAGED PATIENTS

Normal controls (N = 25)

Scores 10 9 8 1 6 5 4 3 2 I 0

24 1

Aphasic patients (N = 53)

Nonaphasic left brain-damaged patients (N = 26)

Right brain-damaged patients (N = 49)

20 10 5 7 6 I

43 5 1

23 1 1 1

3 1

Statistical

tests

Chi2 Aphasics Aphasics

vs. right brain-damaged patients vs. nonaphasic left brain-damaged

patients

26.91 18.09

P <.OOl <.ool

(obtained by 96% of the control patients) was taken as the cut-off point for discriminating “normal” from “pathological” performances. Data reported in Table 2 show that 33 aphasics (62%), 6 right braindamaged patients (12%), and 3 nonaphasic left brain-damaged patients (11%) scored below the cut-off point on the test of symbolic gestures interpretation. The difference between aphasics and right or left nonaphasic braindamaged patients was found to be highly significant on the statistical testing. Relationship between Verbal Semantic Impairment Understand the Meaning of Symbolic Gestures

and Inability

to

Within the aphasic group the degree of association between verbal semantic impairment and inability to understand the meaning of symbolic gestures was investigated. Three patients were discarded from this analysis because, owing to marked inability to maintain the set, they had performed the verbal comprehension test at a chance level, and had

456

GAINOTTI

AND LEMMO TABLE

RELATIONSHIP BETWEEN TO UNDERSTAND

3

VERBAL SEMANTIC IMPAIRMENT AND INABILITY THE MEANING OF SYMBOLIC GESTURES

(A) Scores obtained at the test of symbolic gestures interpretation by the aphasic patients who had obtained a normal (NORMAL) or a pathological (PATHOL) number of semantic errors at the “verbal sound and meaning discrimination test” Score

Path01

Normal ChiP = 4,78 p < .05

10

9 8 7 6 5 4 3 2 1 0 Total

2

36

14

(B) Spearman rank order correlation test between number of semantic errors on the verbal comprehension test and scores obtained on the task of symbolic gestures interpretation rs = .5418 p < .OOl

obtained a number of unrelated errors higher than the sum of the semantic and of the phonemic errors (Gainotti et al., 1975). According to the criteria followed in the above mentioned paper, the number of the semantic errors was considered as pathological when it was higher than that made by about the 95% of the control patients belonging to the same educational level. Table 3 reports the scores obtained on the test of symbolic gesture comprehension by the patients who had obtained a “normal” and a “pathological” number of semantic errors on the “verbal sound and meaning discrimination test.” Among the patients who showed a semantic impairment at the verbal comprehension test, 25 (70%) obtained a pathological performance on the test of symbolic gesture interpretation as well. On the contrary, among the patients who had obtained a “normal” number of semantic errors on the “verbal sound and meaning discrimination test,” only 6 (43%) performed at a pathological level on the test of symbolic gesture comprehension. This difference reached the level of statistical significance (Ch? = 4,78, p < .OS).

In order to study more closely the relationships

between verbal semantic

SYMBOLIC

GESTURES

457

IN APHASIA

impairment and inability to understand the meaning of symbolic gestures, the degree of the association was examined by means of a Spearman rank order correlation test. Results reported in Table 3 confirm that a very significant correlation exists between verbal semantic impairment and nonverbal symbolic disintegration. Relationship Gestures

between Comprehension

and Reproduction

of Symbolic

The hypothesis had been advanced that, if impaired reproduction of pantomimed gestures (ideomotor apraxia) is sometimes due to an inability to understand the meaning of the gesture itself, then a significant correlation should exist between results obtained on the tests of ideomotor apraxia and of symbolic gesture comprehension. This hypothesis was checked within the group of the aphasic patients, by studying the relationship between ideomotor apraxia and incapacity to understand the meaning of symbolic gestures (Table 4). Since no control subject had made any errors on the test of ideomotor apraxia, each patient who had not reached the maximum score of 8 was considered as impaired in reproducing symbolic gestures. Among the patients who had obtained a pathological score on the test of ideomotor apraxia, 17 (81%) also obtained a pathological result on the test of symbolic gesture interpretation. Among the subjects who had reached the maximum score on the test of ideomotor apraxia, 16 (50%) obtained a pathological result on the test of symbolic gesture interpretation. The relationship between impaired reproduction and disturbed comprehension of symbolic gestures reached just the level of statistical significance (ChP = 3,86, p < .OS). However, the degree of the correlation between comprehension and reproduction of symbolic gestures did not reach the level of statistical significance on the Spearman rank order correlation test. DISCUSSION

Our results have shown that: (1) aphasic patients are specifically impaired on a test of symbolic gesture interpretation; (2) within the aphasic group, the inability to understand the meaning of symbolic gestures is highly related to verbal semantic impairment (evaluated on the ground of the number of semantic errors obtained at the “verbal sound and meaning discrimination test”); (3) within the aphasic group, only a slight relationship can be found between comprehension and reproduction of symbolic gestures. The finding of a specific impairment of aphasic patients on a nonverbal test of symbolic gesture interpretation confirms the data obtained in a previous research by Gainotti and Ibba (1972) and is in good agreement with the results obtained by Spinnler and Vignolo (1966), Doehring et al.

458

GAINOTTI

AND TABLE

LEMMO 4

RELATIONSHIPS BETWEEN COMPREHENSION AND REPRODUCTION SYMBOLIC GESTURES IN APHASIC PATIENTS"

OF

Reproduction of symbolic gestures Normal Comprehension Normal Impaired

of symbolic

n Spearman rank bolic comprehension

Impaired

Statistical

tests

gestures 16 16

4 17

Chi* = 3,86 p < .O5

order correlation test between the scores obtained on the tasks of symand of ideomotor apraxia: Y,~= 2,65; p = N.S. (one tailed p < .05).

(1967), Faglioni et al. (1969) in their studies on the comprehension of nonverbal meaningful sounds in aphasia. In fact, all these researches seem to show that aphasic patients, although not impaired in tasks of simple perceptual discrimination, find it very difficult to identify the meaning of a perceptual pattern. Very similar conclusions had been reached by De Renzi and Vignolo (1962) and by Gainotti et al. (1975) in their studies on the acoustic and semantic aspects of auditory language comprehension in aphasia. These authors had shown, in fact, that aphasic patients make many more errors when asked to discriminate the meaning of words in clusters of semantically similar alternatives than when their task consists in discriminating between phonemically similar words. Furthermore, the linkage between verbal and nonverbal aspects of the semantic disintegration in aphasia is stressed by the fact that in our research the incapacity to understand the meaning of symbolic gestures was found highly related to verbal semantic disintegration. All these data strongly support the hypothesis that at least in some forms of aphasia the basic defect does not consist in a sensory or in a motor disorder, but in a much more deeply situated disturbance. This basic trouble could be viewed either as a generalized symbolic disorder (according to the hypothesis advanced first by Finkelnburg) or as a disturbance of the semantic level of integration of language. The hypothesis that the impaired comprehension of symbolic gestures may be due to a generalized disturbance in the capacity to comprehend symbols in any modality is perhaps the simplest manner of interpreting our results. According to this view, both the incapacity to understand the meaning of the symbolic gestures and the verbal semantic impairment should be considered as aspects of a general disorder of the “symbolic function.” This hypothesis, although very interesting, has not yet received a sufficient experimental support, and we prefer to consider it as a speculative interpretation rather than as a testable hypothesis. The alternative hypothesis that the impaired comprehension of symbolic gestures may be

SYMBOLIC

GESTURES

459

IN APHASIA

due to the disintegration of the abstract set of relations existing between verbal sounds and meaning is less simple and evident, but has the advantage of being linked to a more solid and documentated theory. In fact, a consistent number of experimental data give support to the hypothesis that in many forms of aphasia the semantic level of integration of language may be more or less severely impaired. Goodglass, Gleason, and Hyde (19701, Daujat, Gainotti, and Tissot (19741, and Gainotti et al. (1975) have demonstrated, in a large number of research on various aspects of auditory language comprehension in aphasia, that a significant relationship exists between semantic paraphasic production (or anomia) and semantic defect in verbal comprehension. Furthermore, Lhermitte, Derouesne, and Lecours (1971) and Ledent, Gainotti, Messerli, and Tissot (1976) have shown that the disintegration of the semantic systems in aphasia is chiefly evident in patients who present a semantic paraphasic production at the expressive level. All these data seem to show that a true level of integration of language (namely the semantic level) is attained in many forms of aphasia. The hypothesis could then be advanced that this nuclear linguistic disintegration does not impair only verbal expression and comprehension, but also other performances obtained in apparently nonverbal tasks (such as comprehending a symbolic gesture or identifying a nonverbal meaningful sound). In these cases we should admit that when we are asked to explain the meaning of a symbolic gesture, we tend to define it with a verbal label, and that, if the semantic level of integration of language is impaired, this verbally mediated process can also be impaired. In any case, even if the exact meaning of these results is not clear, we would stress the fact that almost % of our aphasic patients were unable to understand the meaning of simple symbolic gestures, a finding which stresses the existence of a nuclear disintegration in aphasia, much more deeply situated than are the factors of performance capabilities. The last aim of our research consisted in studying the relationships existing between disturbed comprehension and impaired reproduction of symbolic gestures. The results of the present research confirm only in part the findings of the previous study (Gainotti and Ibba, 1972), because only a slight relationship was found between disturbed comprehension and impaired reproduction of pantomimed movements. These data seem to show that difficulties involved in reproducing symbolic gestures are due to a true apraxic or executive defect, and very seldom to poor comprehension of the gesture itself. REFERENCES Daujat,

C., Gainotti, G., & Tissot, R. 1974. SW quelques comptihension dans I’aphasie. Correx. 10, 347-365. De Renzi. E.. Scotti, G.. & Spinnler. H. 1969. Perceptual visual recognition. Neurology. 19, 634-642.

aspects

des troubles

and associative

disorders

de la of

GAINOTTI

460

AND LEMMO

De Renzi, E., & Vignolo, L. A. 1%2. Fattori verbali ed extraverbali delta comprensione negli afasici. In Atti XIV Congress0 Nazionale Societir Italiana Neurologia, 443-468.

Doehring, D. G., Dudley, J. G., & Coderre, L. 1967. Programmed instruction in picturesound association for the aphasics. Pholia Phoniatrica, 19, 414-426. Faglioni, P., Spinnler, H., & Vignolo, L. A. 1969. Contrasting behaviour of right and left hemisphere-damaged patients on a discriminative and a semantic task of auditory recognition. Cortex, 5, 366-389. Finkelnburg, F. C. 1870. Niederrheinische Gesellschaft, Sitzung vom 21 Marz 1870. Berlin Klinik

Wochenschr,

7, 449-460.

Gainotti, G., Caltagirone, C., & Ibba A. 1975. Semantic and phonemic aspects of auditory language comprehension in aphasia. Linguistics, 154/155, 15-29. Gainotti, G., & Ibba, R. 1972. La comprensione de1 significato dei gesti simbolici negh afasici. Minerva Psichiatrica e Psicologica, 13, 1-9. Gainotti, G., & Tiacci, C. 1971. The relationship between disorders of visual perception and unilateral spatial neglect. Neuropsychologia, 9, 45 l-459. Goldstein, K. 1948. Language and language disturbances. New York: Grune and Stratton. Goodglass, H., Gleason, J., & Hyde, M. 1970. Some dimensions of auditory language comprehension in aphasia. Journal of Speech and Hearing Research, 13, 595-606. Head, H. 1926. Aphasia and kindred disorders ofspeech. London: Cambridge University Press. Ledent, S., Gainotti, G., Messerli, P., & Tissot, R. 1976. Logique tlementaire et champs semantiques dans l’aphasie. Revue Neurologique (to be published). Lhermitte, F., Derouesne, J., & Lecours, A. R. 1971. Contribution a I’ttude des troubles semantiques dans l’aphasie. Revue Neurologique, 125,81101. Spinnler, H., & Vignolo, L. A. 1966. Impaired recognition of meaningful sounds in aphasia. Cortex,

2,337-348.