NAMING TO PICTURE VERSUS DESCRIPTION IN THREE APHASIC SUBGROUPS! H. Goodglass and D. T. Stuss (Boston Veterans Administration Hospital and Department of Neurology, Boston University School of Medicine)
While difficulty in retrieving object names is ubiquitous in aphasia, there is evidence to suggest that impaired performance in this task is not a unitary phenomenon but varies among aphasic subgroups (Howes, 1967; Goodglass, Klein, Carey and Jones, 1966; Goodglass, Kaplan, Weintraub and Ackerman, 1976; Benson, in press). While many prior studies of naming difficulty have examined features common to all aphasics (Barton, Maruszewski and Urrea, 1969; Goodglass, Barton and Kaplan, 1968; Newcombe, Oldfield and Wingfield, 1965; Rochford and Williams, 1965), the clinical features of impaired naming differ among diagnostic subgroups (Luria, 1970). Some patients typically produce phonetic approximations to the target, some produce semantically related paraphasias, some recognize and repeat the word when it is supplied and some can neither recognize nor repeat it. In addition, patients differ markedly in their ability to benefit from a cue (Pease and Goodglass, 1978). Recent efforts in our laboratory have concentrated on probing for characteristics which might shed light on differences in the mechanisms underlying various forms of disordered naming. For example, Goodglass, Kaplan et al. (1976) found that conduction aphasics and Broca's aphasics had some success in reporting the initial sound and number of syllables in words which they could not fully retrieve (the tip-of-the-tongue phenomenon). In contrast, for Wernicke and anomic patients word-finding appeared to be an "all or none" process. If these patients were unable to retrieve a word, they also gave no sign of partial knowledge of the word. The present study tests an hypothesis which arises from this observation. Namely, that Broca's and conduction aphasics, when they fail in the immediate association from concept to word retrieval, have access to periphe1 Research support was derived in part from the Medical Research Service of the Veterans Administration and in part from USPHS Grants NS 06209 to Boston University and NS 07615 to Clark University. Personal support for the second author came from the Ontario Mental Health Foundation and the National Research Council of Canada.
Cortex (1979) 15, 199-211.
200
H. Goodglass and D. T. Sluss
ral associations which aid them in the eventual access to the word. It is further hypothesized that for the Wernicke's and anomic aphasics, the immediate association is the only functioning channel; that when the immediate one-to-one association fails, these patients are deficient in using peripheral associations to retrieve the target. In the present study we therefore compared Broca's, anomie, and Wernicke's aphasics under two conditions of stimulation: picture presentation versus a group of orally presented associations to the target (referred to as "oral description"). It was presumed that picture presentation would permit response either by direct evocation of the name by the pictured concept (available to all groups of patients) or by mobilization of more remote associates to trigger the correct name (Goodglass and Baker, 1976), a method more available to Broca's than to the two posterior groups. It was further presumed that the presentation of oral associates would place both the Wernicke aphasics and the anomics at a disadvantage with respect to Broca's aphasics, since this mode of presentation appears to force the patient to funnel in on the target word via peripheral associations. The specific experimental hypotheses were, first, that Broca's aphasics would perform approximately equivalently in the two modes of stimulus presentation while Wernicke and anomic aphasics would be relatively impaired in response to oral associates. It was also expected that Wernicke and anomic aphasics would tend to respond quickly or else fail, while correct responses from Broca's aphasics would be more widely distributed in latency. Barton, Matuszewski and Urrea (1969) included confrontation naming and naming to description in their comparison among modalities of stimulation for naming. Picture confrontation was the more effective stimulus, but there was no variation among types of aphasics, nor were there measures of response latency. In the present experiment, the differentiation among types of aphasics is expected.
MATERIAL AND METHOD
Subjects Twenty-three aphasic males, selected over a period of 11/2 years from the Neurobehavioral Unit, Boston Veterans Administration Hospital, were tested. The essential criteria for inclusion in the study were a moderate impairment in naming and unilateral left hemisphere pathology. Based on their language profiles on the Boston Diagnostic Aphasia Examination (BDAE» (Goodglass and Kaplan, 1972) and on knowledge of lesion location derived form the psysical neurological examination and Computerized Tomography scan information, the patients were subdivided into the following three diagnostic categories: 10 Broca's aphasics, 7 Wernicke's aphasics and 6 anomics. The patients classified as Broca's aphasics had markedly reduced and effortful
Naming to picture versus description
201
speech output with impaired articulation; their auditory comprehension was mildly to moderately impaired, but superior to their oral production. The patients classified as Wernicke's aphasics had fluent speech output with paraphasia and lacking in substantives; while all had initially manifested severe auditory comprehension disorders, their current auditory comprehension varied over a wide range, overlapping that of the Broca's aphasics. Patients classified as anomics had fluent speech which lacked substantives but was without paraphasia. They had good to mildly impaired auditory comprehension. The anomics were least impaired on a six point severity rating scale (mean rating of 3.25), the Wernicke's were next most severely impaired (rating of 2.43) and the Broca's most severely impaired (rating of 1.57). All patients were right-handed, but two Wernicke's aphasics had a familial history of left-handedness. Two of the subjects included in the Wernicke classification had deep rather than cortical pathology. Further details as to age, severity, comprehension and etiology are summarized in Table I. TABLE I
Age, Severity, Comprehension and Etiology of Aphasic Groups
N
Age Mean
10
54.4
6.1
1.57
.48
9 Vascular 1 Surgery
Wernicke
7
55.9
12.4
2.43
-.26
6 Vascular 1 Trauma
Anomic
6
56.0
10.3
3.25
.50
Broca
S.D.
Mean severitya
Mean comprehensionb
Etiology
5 Vascular 1 Alzheimers
a Based on the 6 step scale from 0 (no communication) to 5 (no discernible speech handicap) as specified in the Boston Diagnostic Aphasia Examination. b Based on the Auditory Comprehension score in Z score units, range from 2 (severe deficit) to + 2 (minimal deficit) as specified in the Boston Diagnostic Aphasia Examination.
Stimulus material and Procedure The naming task consisted of twenty target words selected from the Boston Naming Test (Kaplan, Goodglass and Weintraub, 1978). Subjects were required to name the target word either to visual confrontation, or to a brief oral description consisting of a series of three distinctive characteristics of the referent. The instructions for visual confrontation were as follows "I want to see how well you can name things. I'm going to show you a picture. Tell me the name of the object as quickly as you can." Speed of response was noted, timing commencing as soon as the picture was presented. If a paraphasic response was made, the subject was informed it was wrong and asked to continue trying. If no correct response was given after thirty seconds had elapsed, a phonemic cue was given consisting of the first two phonemes. That is, if the target word was "flower, the examiner cued "It's a fl ... ". Figure 1 presents two examples of the visual stimuli.
H . G oodglass and D. T. Stuss
202
Fig. 1 -
Samples of pictures used for visual confrontation naming.
For the oral presentation, the examiner stated "I'm going to describe something. Tell me the name of what I'm describing as quickly as you can." Examples of the oral description corresponding to the two pictures in Figure 1 are as follows: (tree) - It grows tall. It has a trunk covered with bark. It has branches and leaves. It's a ... (camel) - This animal lives in the desert. It carries people or bundles. It goes for a long time without water. It's a ... Timing began after the last phrase. The subject was informed if a response was incorrect, and asked to continue trying. If no correct response was given after thirty seconds had elapsed, the picture of the object was presented as a visual cue. If this aid failed to elicit the correct response within 15 seconds, a phonemic cue was given as described above. Minor inaccuracies in the articulation of individual sounds were not penalized. Subjects were tested on two separate days, all twenty items being presented each day. For the first session, the first ten trials were administered either to visual confrontation or oral description, the remaining ten given in the other modality. On the second day, the same twenty items were administered, the order of the modality presentation being reversed. Results from both days were summed, yielding a total of 20 trials in each modality. Order of modality presentation was randomized across subjects. Correct responses were subdivided according to the following arbitrarily selected time intervals, reflecting the latency to correct response after stimulus presentation: 0-5, 6-10, 11-20, and 21-30 seconds. In addition, the last three intervals were combined for certain analyses. For each modality, three types of percentage scores were used in the computations. The most comprehensive was Total Correct/Total Trials, or the number of items correct within 30 seconds, divided by 20. Thus a total of 15 items correct within the 30 second time limit rated 75 percent. The number of correct responses within any specified time interval was treated in two ways. A percentage based on the number correct for a time interval over the total number of 20
Naming to picture versus description
203
trials for that modality reflected an absolute ability to name in relation to speed. This was labeled Correct/Total Trials for each specific interval. Thus, if ten responses to visual confrontation were correct within the first five seconds after stimulus presentation, the 0-5 Correct/Total Trials percentage for the visual modality would be 10/20 = 50%. The second time-interval treatment was a percentage based on the number correct in a given time interval over the total number of correct responses, and was labeled Correct/Total Correct. This percentage compares an individual's naming ability in a given time interval to only those responses that he named correctly within the 30 second time limit. Since the total correct in the previous example had been 15 out of the 20 trials, the 0-5 Correct/Total Correct score would be 10/15 = 66%. Statistical analyses
Two factor ANOVA's compared the three diagnostic groups on their ratings on the comprehension scores and severity ratings from the BDAE. Each dependent measurement was then analyzed in a Condition (oral or vispal) by Group analysis of variance with repeated measures across conditions. To ensure that possible naming differences were not due solely to comprehension or severity variability, the same dependent measurements were analyzed in Condition by Group analyses of covariance using the BDAE comprehension and severity scores as covariates. Finally t tests were used to assess group differences in responsiveness to cues. Required level of significance for all tests was arbitrarily set at .05. Maximum group discrimination and percentage of correct case classification were analyzed by multivariate discriminant function analysis. Using a direct solution method, the following variables selected from the oral modality were analyzed: (1) Total Correct for the entire 30 sec. period; (2) 0-5" Correct/Total Trials; (3) 6-30" Correct/Total Trials; (4) 0-5" Correct/Total Correct; (5) 6-30" Correct/ Total Correct. A second discriminant function employed the same variables from the visual presentation. Comparison with a stepwise solution was made by combining the above variables from both modalities.
RESULTS
When the three groups were compared on their comprehension scores, the Wernicke's aphasics had a significantly worse comprehension deficit than the Broca's aphasics (F = 5.4; do£. = 2, 20; P = .014). Significance was not reached between Anomics and Wernicke's due to the smaller N (See Table I). In addition, the Broca's aphasics were significantly lower than the anomies on the severity rating of the BDAE (F = 10.2; d.£. = 2, 20; P < .001), no other group differences being significant.
H. Goodglass and D. T. Stuss
204
Differences in naming
Two-factor ANOV AS yielded a significant Group X Modality interaction effect for the total number of items correctly named (F = 10.29; d.£. = 2, 20; P = .001). Comparison of groups in overall success in naming (see Figure 2) revealed that, on the whole, naming to visual confrontation was .""".""•• BROCA'S APHASICS •.•••• WERNICKE'S APHASICS -
80
60
B~" " " " " " " " " " " ' ' ' ' ' ' ' ' ' ' ' ' ' "' 'B W..
A~'~~'~'~---------------------A
TOTAL CORRECT TOTAL
TRIALS
..,.,.•.•.•.,.
40
...........
"""',
'.
""'W
20
VISUAL
Fig. 2 -
ANOMIC APHASICS
ORAL
Interaction between type of aphasia and modality of testing.
easier than naming to oral associative description. However, this result was due to the differential performance of the Broca's and especially that of the Wernicke's aphasics, both post hoc measurements significant at p. < .05; the anomies performed identically in the two conditions. In spite of the Broca's aphasics' significantly more severe aphasia they were somewhat more proficient than the other two groups in both naming conditions. This group difference did not reach significance in visual naming. In naming to oral stimulation, however, the Wernicke's differed significantly only from the Broca's, the post hoc test again significant at p < .05. Given the fact that response to oral stimulation is dependent on auditory comprehension, it could be reasoned that the disproportionate drop of the Wernicke's aphasics in the oral condition was due to their imperfect comprehension of the stimuli. However, when the factor of auditory comprehension was introduced in an analysis of covariance, there was no significant change in the F value for the interaction between groups and conditions (F = 9.78; d.£. = 2, 19; P = .002). Post hoc t tests were similarly unchanged. Use of the severity of aphasia as a covariate also yielded unchanged
Naming to picture versus description
205
results. Comparison of the F values for the ANOV A and ANCOV A, for Total Correct and other significant measurements, are presented in Table II. The ANOVA based on the percent Correct/Total Trials in the first 5 seconds is similar to that for Total Correct and post-hoc testing of interactions yielded identical results for the two ANOVA's. TABLE II
Comparison of Significance Levels Obtained by ANOVA to Levels Obtained by Analysis of Covariance with Comprehension or Severity as Co variates
Variable
p levels by ANOVA
p levels by ANCOVA Comprehension
Severity
Total Correct/Total Trials Group Condition Interaction
.012 .001 .001
.038 .001 .002
.006 .001 .001
.015 .001 .048
.042 .001 .056
.003 .001 .048
.385 .020 .307
.467 .024 .326
.105 .020 .307
.381 .028 .354
.469 .032 .373
.102 .028 .354
0-5" Correct/Total Trials Group Condition Interaction 0-5" Correct/Total Correct Group Condition Interaction 6-30" Correct/Total Times Group Condition Interaction
Further differences between the groups and conditions were apparent when we compared short latency « 5 sec) and long latency (6-30 sec) responses (see Figure 3). Here the analysis based on the percent of correct responses produced during the given time interval was similar to that for the total correct. All groups produced a greater proportion of short latency responses to visual than to oral presentation (F = 6.40; d.f. = 1, 20 ; P = .02). That is, visual presentation came close to eliciting either an immediate response or no response for all three groups. By the same token, the proportion of long latency responses was greater under oral than visual stimulation (F = 5.68; d.£. = 1, 20, P = .03).
H. Goodglass and D. T. Stuss
206
.............. BROCA 'S APHASICS •• _,_ .• WERNICKE ' S APHASICS
~'~ """' '' ' ' ' ' ' ' ' ' ' ' 'B
80
W,
- - ANOMIC APHASICS
" .
'110 "
" ,
.... ,. "" ........... A
60
"W
CO RRECT TOTAL CORR ECT
.W
49
20
ORAL
VISU AL
0-5
0/
Fig. 3 - Comparison testing.
0/
VISUAL
Se c
short and long latency responses by type
ORAL
6-30
0/
Sec
aphasia and modality
Inspection of this figure suggests that the increased proportion of correct delayed responses to oral presentation is determined by the anomic and Wernicke's aphasics, while Broca's aphasics show almost no change between presentation modalities with respect to the distribution of immediate versus delayed responses. However, when the results were treated as coming from three separate groups, the inter-group differences did not reach significance. Consequently a series of one factor ANOVAS was used to compare the 10 Broca's aphasics and the 13 combined posterior (Wernicke's and Anomie) aphasics in percent correct delayed responses falling in the several response latency ranges under visual and auditory stimulation. Again, comparing only modality differences for all aphasics as one group, overall percent response to oral stimulation was greater than visual in the entire 6-30 second interval (F = 4.33; d.f. = 1, 22; P = .05). This was due to the fact that posterior aphasics had a greater proportion of responses to oral stimulation in each delayed response interval, although only one of these intervals taken alone (11-20 sec), gave a significant F value (F = 4.4; d.£. = 1, 21; P = .048) (see Figure 4).
Classification of subjects Multivariate discriminant function analyses comparing the three groups by either combining the two modalities of presentation in a step-wise so-
Naming to picture versus description
207 • -
BROC'A 'S APHASICS
• "... ,," POSTERIOR APHASICS
80
•
60 CORRECT TOTAL CORRECT 40
20
0-5
6~10
11-20
21-30
0-5
VISUAL
Fig. 4 modalities.
6-lIi
11-20
21-30
ORAL
Breakdown of naming responses by latency interval for visual and oral stimulation
lution or using the oral and visual measurements separately in a direct solution indicated that the groups could be significantly separated using the naming results, and that the individuals could be classified into their diagnostic categories with a high degree of accuracy. Anomies were most difficult to classify. Using the visual modality alone yielded a lower level of confidence that the classification of the patient was made correctly. These results are summarized in Table III.
Responsiveness to cueing Cues were given under the three conditions described in the methodology: (1) a visual cue was given after failure to name to oral associative description; (2) a phonemic cue was given if this visual cue failed to elicit a correct response; (3) a phonemic cue was given after failure to name to visual confrontation. Results for each cueing condition were tabulated as percentages of correct responses over the number of errors. These are summarized in Table IV. Comparisons of the responsiveness to different types of cues revealed that phonemic cueing after failure to name to visual confrontation resulted in a higher proportion of correct names than a visual cue after failure to name to oral associative description. This difference reached significance for the Broca's (t = 2.84, P < .02) and anomie aphasics (t = 2.25, P = .05). Comparison of the groups showed that, for all cueing condition, the Broca's
H. Goodglass and D. T. Stuss
208
TABLE III
Discrimination and Classification Percentages, for Three Discriminant Function Analyses
Broca
Predicted category Wernicke
Anomic
Averageb probability
Broca (10) Wernicke (7) Anomics (6)
70 (7)a (0) 33.3 (2)
20 (2) 85.7 (6) (0)
10 (1) 14.3 (1) 66.7 (4)
.717 .855 .801
Broca (10) Wernicke (7) Anomics (6)
80 (8) (0) 16.7 (1)
(0) 85.7 (6) 50.0 (3)
20 (2) 14.3 (1) 33.3 (2)
.894 .861 .651
80 (8) (0) 33.3 (2)
20 (2) 71.4 (5) (0)
(0) 28.6 (2) 66.7 (4)
Diagnostic category Combined modalities
o
o
Oral
o
o
Visual Broca (10) Wernicke (7) Anomics (6)
o
o
o
.611 .686 .730
a The values reflect the percent of subjects correctly classified into their a priori diagnostic category, on the basis of specific naming abilities. Actual numbers of subjects are given in parenthesis. b The average probability is an index of the overall confidence of the classification decision based on the measurements used.
TABLE IV
Percent Correct Responses to Cueing
For items failed on oral description Visual cue Phonemic cue Wernicke'1 Broca's Anomics
38.3 28.3 11.4
91.0 53.8 34.7
For items failed on visual confrontation Phonemic cue 76.5 44.8 27.7
aphasics responded with a higher proportion of correction to cues than both other aphasics groups, the Wernicke's aphasics having the second largest percentage. Broca's aphasics had a significantly higher proportion than did anomics for correct responses both to phonemic cues after failure to name to visual presentation (t = 3.23, P < .01) and for visual cues after failure to name to oral description (t = 2.42, P < .05). Finally, when given a phonemic cue after a visual cue had failed, Broca's aphascis were almost perfect in responding to the cue, and had a significantly higher proportion of correct responses than either anomics (t = 7.13, P < .001) or Wernicke's aphasics (t = 4.07, P < .01).
Naming to picture versus description
209
DISCUSSION
This study was designed on the presumption that naming to visual confrontation and naming to associative description differentially evoked two different paths to the target response; that the first facilitated an immediate and direct association, while the second led to the convergence of peripheral associations to trigger the desired response. The validity of this assumption is supported by the finding that short latency responses predominated in the visual confrontation over the associative description condition, for all aphasic subgroups. It was further expected that Broca's aphasics would have relatively more success than the posterior aphasics on reaching the target response via the route of peripheral associations, but that the two groups would be more alike in response to visual confrontation. Here again the results are, at least partially, in accord with expectations. Broca's aphasics were insignificantly superior to the posteriors in naming to visual confrontation, but significantly superior to the Wernicke's group in naming to oral association. Anomics were unchanged in their total correct responses under the two conditions. A corrollary prediction, concerning the distribution of latencies was not borne out. It had been reasoned that long latency responses were an index of the extent to which naming took place via the medium of converging peripheral associations to arouse the target word, and it was expected that Broca's aphasic would achieve the greatest number of successes by this strategy. In fact, however, both Wernicke and anomie aphasics exceeded Broca's aphasics in their proportion of long latency responses under the oral association condition. However, there is no compelling reason to assume that response via peripheral assocition needs to take more than 5 seconds. The elevated proportion of delayed responses made by both groups of posterior aphasics in this condition may merely signify that they are deficient and therefore slower in responding via the peripheral associative channel. It is noted that while the anomics achieved the same total mean correct responses to oral associations as to visual confrontation, they, like the Wernicke aphasics, had a large proportion of long latency responses to oral associa tions. The most severe criticism possible for the approach used in this experiment is that the oral associative stimuli might selectively penalize the Wernicke's aphasics, who were the most deficient in auditory comprehension. However, the fact that covariance on the factor of auditory comprehension did not change the outcome would seem to answer this criticism. The oral associations used were evidently sufficiently easy auditorily so as not to influence the performance of the \Vernicke's aphasics as a function of their deficit in comprehension.
210
H. Goodglass and D. T. S'uss
The present results are consistent with Barton et al.'s (1969) comparison between visual confrontation and oral description as stimuli for a naming response, in that the overall efficiency of visual confrontation exceeds that of oral definitions. However, by examining latencies and the differential behavior of Broca's, Wernicke's, and anomie aphasics we have been able to show that the relative drop in naming to auditory stimulation is due primarily to Wernicke's aphasics and that this condition also results in a large proportion of long latency responses by posterior, but not by Broca's aphasics. Facilitation of naming by cueing further differentiated between the Broca's aphasics and the two posterior aphasic groups. When cued pictorially after failure to oral associates, the Broca's aphasics responded correctly more than three times as often as the anomics. When cued phonemic ally after failure to name a picture, Broca's aphasics responded significantly more often than either of the other groups. These results confirm those recently reported by Pease and Goodglass (1978). As these authors found, the order of responsiveness to cueing by the several groups is the same as their original order of proficiency in naming. However, in the present results, the superiority of the Broca's aphasics in responding to phonemic cueing appears to be disproportionate to their superiority in naming, suggesting that a qualitative as well as a quantitative factor is at work. These results are consistent with prior evidence that the mechanism of disordered naming by Broca's aphasics is different from that of Wernicke's and anomie aphasics.
SUMMARY
Twenty-three male aphasics, classified as Broca's, Wernicke's and anomic, were tested on their ability to name objects to either visual confrontation or oral associative description. For the Broca's and Wernicke's aphasics, naming to visual confrontation was significantly better than to oral description. Broca's aphasics tended to produce more correct names than both other groups in both conditions, although significance was reached only in oral description. Differences were not significantly affected by the comprehension deficit or severity of aphasia. With picture naming, all groups tended to name immediately or not at all. For oral description, there was a greater proportion of long latency responses for the posterior patients. When given phonemic or visual cues to assist naming, Broca's aphasics benefited the most, the anomics performing most poorly. All these results suggest qualitative differences in naming ability in aphasic subgroups. Acknowledgments. The authors gratefully acknowledge Errol Baker for his assistance with the statistical analyses and Mary Hyde for the computer analysis of the data.
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REFERENCES BARTON, M. 1., MARUSZEWSKI, M., and URREA, D. (1969) Variation of stimulus context and its effect on word-finding ability in aphasics, Cortex, 5, 351-365. BENSON, D. F. (in press) Neurologic correlates of anomia, in Studies in Neurolinguistics, Vo. IV, ed. by H. A. Whitaker and H. Whitaker, Academic Press, New York. GOODGLASS, H., and BAKER, E. (1976) Semantic field, naming, and auditory comprehension in aphasia, Brain and Language, 3, 359-374. - , BARTON, M., and KAPLAN, E. (1968) Sensory modality and object-naming in aphasia, J. Speech Hear. Res., 11, 488-496. - , KAPLAN, E., WEINTRAUB, S., and ACKERMAN, N. (1976) The "tip-of-the-tongue" phenomenon in aphasia, Cortex, 12, 145-153. - , KLEIN, B., CAREY, P., and JONES, K. (1966) Specific semantic word categories in aphasia, Cortex, 2, 74-89. HOWES, D. (1967) Some experimental investigations of language in aphasia, in Research in Verbal Behavior and Some Neuropsysiological Implications, ed. by K. Salzinger and S. Salzinger, Academic Press, New York. KAPLAN, E., GOODGLASS, H., and WEINTRAUB, S. (1978) The Boston Naming Test, Boston. LURIA, A. R. (1970) Traumatic Aphasia, Mouton, The Hague. NEWCOMBE, F., OLDFIELD, R. c., and WINGFIELD, A. (1965) Object-naming by dysphasic patients, Nature, 207, 1217-1218. PEASE, D., and GOODGLASS, H. (1978) The effects of cueing on picture-naming aphasia, Cortex, 14, 178-189. ROCHFORD, G., and WILLIAMS, M. (1965) Studies in the development and breakdown of the use of names. IV. The effects of word frequency, J. Neurol. Neuros. Psychiat., 28, 407-413.
H. Goodglass, Ph. D., Psychology Service, Veterans Administration Hospital, 150 S. Huntington Ave., Boston, Mass. 02130.
While difficulty in retrieving object names is ubiquitous in aphasia, there is evidence to suggest that impaired performance in this task is not a unitary phenomenon but varies among aphasic subgroups (Howes, 1967; Goodglass, Klein, Carey and Jones, 1966; Goodglass, Kaplan, Weintraub and Ackerman, 1976; Benson, in press). While many prior studies of naming difficulty have examined features common to all aphasics (Barton, Maruszewski and Urrea, 1969; Goodglass, Barton and Kaplan, 1968; Newcombe, Oldfield and Wingfield, 1965; Rochford and Williams, 1965), the clinical features of impaired naming differ among diagnostic subgroups (Luria, 1970). Some patients typically produce phonetic approximations to the target, some produce semantically related paraphasias, some recognize and repeat the word when it is supplied and some can neither recognize nor repeat it. In addition, patients differ markedly in their ability to benefit from a cue (Pease and Goodglass, 1978). Recent efforts in our laboratory have concentrated on probing for characteristics which might shed light on differences in the mechanisms underlying various forms of disordered naming. For example, Goodglass, Kaplan et al. (1976) found that conduction aphasics and Broca's aphasics had some success in reporting the initial sound and number of syllables in words which they could not fully retrieve (the tip-of-the-tongue phenomenon). In contrast, for Wernicke and anomic patients word-finding appeared to be an "all or none" process. If these patients were unable to retrieve a word, they also gave no sign of partial knowledge of the word. The present study tests an hypothesis which arises from this observation. Namely, that Broca's and conduction aphasics, when they fail in the immediate association from concept to word retrieval, have access to periphe1 Research support was derived in part from the Medical Research Service of the Veterans Administration and in part from USPHS Grants NS 06209 to Boston University and NS 07615 to Clark University. Personal support for the second author came from the Ontario Mental Health Foundation and the National Research Council of Canada.
Cortex (1979) 15, 199-211.
200
H. Goodglass and D. T. Sluss
ral associations which aid them in the eventual access to the word. It is further hypothesized that for the Wernicke's and anomic aphasics, the immediate association is the only functioning channel; that when the immediate one-to-one association fails, these patients are deficient in using peripheral associations to retrieve the target. In the present study we therefore compared Broca's, anomie, and Wernicke's aphasics under two conditions of stimulation: picture presentation versus a group of orally presented associations to the target (referred to as "oral description"). It was presumed that picture presentation would permit response either by direct evocation of the name by the pictured concept (available to all groups of patients) or by mobilization of more remote associates to trigger the correct name (Goodglass and Baker, 1976), a method more available to Broca's than to the two posterior groups. It was further presumed that the presentation of oral associates would place both the Wernicke aphasics and the anomics at a disadvantage with respect to Broca's aphasics, since this mode of presentation appears to force the patient to funnel in on the target word via peripheral associations. The specific experimental hypotheses were, first, that Broca's aphasics would perform approximately equivalently in the two modes of stimulus presentation while Wernicke and anomic aphasics would be relatively impaired in response to oral associates. It was also expected that Wernicke and anomic aphasics would tend to respond quickly or else fail, while correct responses from Broca's aphasics would be more widely distributed in latency. Barton, Matuszewski and Urrea (1969) included confrontation naming and naming to description in their comparison among modalities of stimulation for naming. Picture confrontation was the more effective stimulus, but there was no variation among types of aphasics, nor were there measures of response latency. In the present experiment, the differentiation among types of aphasics is expected.
MATERIAL AND METHOD
Subjects Twenty-three aphasic males, selected over a period of 11/2 years from the Neurobehavioral Unit, Boston Veterans Administration Hospital, were tested. The essential criteria for inclusion in the study were a moderate impairment in naming and unilateral left hemisphere pathology. Based on their language profiles on the Boston Diagnostic Aphasia Examination (BDAE» (Goodglass and Kaplan, 1972) and on knowledge of lesion location derived form the psysical neurological examination and Computerized Tomography scan information, the patients were subdivided into the following three diagnostic categories: 10 Broca's aphasics, 7 Wernicke's aphasics and 6 anomics. The patients classified as Broca's aphasics had markedly reduced and effortful
Naming to picture versus description
201
speech output with impaired articulation; their auditory comprehension was mildly to moderately impaired, but superior to their oral production. The patients classified as Wernicke's aphasics had fluent speech output with paraphasia and lacking in substantives; while all had initially manifested severe auditory comprehension disorders, their current auditory comprehension varied over a wide range, overlapping that of the Broca's aphasics. Patients classified as anomics had fluent speech which lacked substantives but was without paraphasia. They had good to mildly impaired auditory comprehension. The anomics were least impaired on a six point severity rating scale (mean rating of 3.25), the Wernicke's were next most severely impaired (rating of 2.43) and the Broca's most severely impaired (rating of 1.57). All patients were right-handed, but two Wernicke's aphasics had a familial history of left-handedness. Two of the subjects included in the Wernicke classification had deep rather than cortical pathology. Further details as to age, severity, comprehension and etiology are summarized in Table I. TABLE I
Age, Severity, Comprehension and Etiology of Aphasic Groups
N
Age Mean
10
54.4
6.1
1.57
.48
9 Vascular 1 Surgery
Wernicke
7
55.9
12.4
2.43
-.26
6 Vascular 1 Trauma
Anomic
6
56.0
10.3
3.25
.50
Broca
S.D.
Mean severitya
Mean comprehensionb
Etiology
5 Vascular 1 Alzheimers
a Based on the 6 step scale from 0 (no communication) to 5 (no discernible speech handicap) as specified in the Boston Diagnostic Aphasia Examination. b Based on the Auditory Comprehension score in Z score units, range from 2 (severe deficit) to + 2 (minimal deficit) as specified in the Boston Diagnostic Aphasia Examination.
Stimulus material and Procedure The naming task consisted of twenty target words selected from the Boston Naming Test (Kaplan, Goodglass and Weintraub, 1978). Subjects were required to name the target word either to visual confrontation, or to a brief oral description consisting of a series of three distinctive characteristics of the referent. The instructions for visual confrontation were as follows "I want to see how well you can name things. I'm going to show you a picture. Tell me the name of the object as quickly as you can." Speed of response was noted, timing commencing as soon as the picture was presented. If a paraphasic response was made, the subject was informed it was wrong and asked to continue trying. If no correct response was given after thirty seconds had elapsed, a phonemic cue was given consisting of the first two phonemes. That is, if the target word was "flower, the examiner cued "It's a fl ... ". Figure 1 presents two examples of the visual stimuli.
H . G oodglass and D. T. Stuss
202
Fig. 1 -
Samples of pictures used for visual confrontation naming.
For the oral presentation, the examiner stated "I'm going to describe something. Tell me the name of what I'm describing as quickly as you can." Examples of the oral description corresponding to the two pictures in Figure 1 are as follows: (tree) - It grows tall. It has a trunk covered with bark. It has branches and leaves. It's a ... (camel) - This animal lives in the desert. It carries people or bundles. It goes for a long time without water. It's a ... Timing began after the last phrase. The subject was informed if a response was incorrect, and asked to continue trying. If no correct response was given after thirty seconds had elapsed, the picture of the object was presented as a visual cue. If this aid failed to elicit the correct response within 15 seconds, a phonemic cue was given as described above. Minor inaccuracies in the articulation of individual sounds were not penalized. Subjects were tested on two separate days, all twenty items being presented each day. For the first session, the first ten trials were administered either to visual confrontation or oral description, the remaining ten given in the other modality. On the second day, the same twenty items were administered, the order of the modality presentation being reversed. Results from both days were summed, yielding a total of 20 trials in each modality. Order of modality presentation was randomized across subjects. Correct responses were subdivided according to the following arbitrarily selected time intervals, reflecting the latency to correct response after stimulus presentation: 0-5, 6-10, 11-20, and 21-30 seconds. In addition, the last three intervals were combined for certain analyses. For each modality, three types of percentage scores were used in the computations. The most comprehensive was Total Correct/Total Trials, or the number of items correct within 30 seconds, divided by 20. Thus a total of 15 items correct within the 30 second time limit rated 75 percent. The number of correct responses within any specified time interval was treated in two ways. A percentage based on the number correct for a time interval over the total number of 20
Naming to picture versus description
203
trials for that modality reflected an absolute ability to name in relation to speed. This was labeled Correct/Total Trials for each specific interval. Thus, if ten responses to visual confrontation were correct within the first five seconds after stimulus presentation, the 0-5 Correct/Total Trials percentage for the visual modality would be 10/20 = 50%. The second time-interval treatment was a percentage based on the number correct in a given time interval over the total number of correct responses, and was labeled Correct/Total Correct. This percentage compares an individual's naming ability in a given time interval to only those responses that he named correctly within the 30 second time limit. Since the total correct in the previous example had been 15 out of the 20 trials, the 0-5 Correct/Total Correct score would be 10/15 = 66%. Statistical analyses
Two factor ANOVA's compared the three diagnostic groups on their ratings on the comprehension scores and severity ratings from the BDAE. Each dependent measurement was then analyzed in a Condition (oral or vispal) by Group analysis of variance with repeated measures across conditions. To ensure that possible naming differences were not due solely to comprehension or severity variability, the same dependent measurements were analyzed in Condition by Group analyses of covariance using the BDAE comprehension and severity scores as covariates. Finally t tests were used to assess group differences in responsiveness to cues. Required level of significance for all tests was arbitrarily set at .05. Maximum group discrimination and percentage of correct case classification were analyzed by multivariate discriminant function analysis. Using a direct solution method, the following variables selected from the oral modality were analyzed: (1) Total Correct for the entire 30 sec. period; (2) 0-5" Correct/Total Trials; (3) 6-30" Correct/Total Trials; (4) 0-5" Correct/Total Correct; (5) 6-30" Correct/ Total Correct. A second discriminant function employed the same variables from the visual presentation. Comparison with a stepwise solution was made by combining the above variables from both modalities.
RESULTS
When the three groups were compared on their comprehension scores, the Wernicke's aphasics had a significantly worse comprehension deficit than the Broca's aphasics (F = 5.4; do£. = 2, 20; P = .014). Significance was not reached between Anomics and Wernicke's due to the smaller N (See Table I). In addition, the Broca's aphasics were significantly lower than the anomies on the severity rating of the BDAE (F = 10.2; d.£. = 2, 20; P < .001), no other group differences being significant.
H. Goodglass and D. T. Stuss
204
Differences in naming
Two-factor ANOV AS yielded a significant Group X Modality interaction effect for the total number of items correctly named (F = 10.29; d.£. = 2, 20; P = .001). Comparison of groups in overall success in naming (see Figure 2) revealed that, on the whole, naming to visual confrontation was .""".""•• BROCA'S APHASICS •.•••• WERNICKE'S APHASICS -
80
60
B~" " " " " " " " " " " ' ' ' ' ' ' ' ' ' ' ' ' ' "' 'B W..
A~'~~'~'~---------------------A
TOTAL CORRECT TOTAL
TRIALS
..,.,.•.•.•.,.
40
...........
"""',
'.
""'W
20
VISUAL
Fig. 2 -
ANOMIC APHASICS
ORAL
Interaction between type of aphasia and modality of testing.
easier than naming to oral associative description. However, this result was due to the differential performance of the Broca's and especially that of the Wernicke's aphasics, both post hoc measurements significant at p. < .05; the anomies performed identically in the two conditions. In spite of the Broca's aphasics' significantly more severe aphasia they were somewhat more proficient than the other two groups in both naming conditions. This group difference did not reach significance in visual naming. In naming to oral stimulation, however, the Wernicke's differed significantly only from the Broca's, the post hoc test again significant at p < .05. Given the fact that response to oral stimulation is dependent on auditory comprehension, it could be reasoned that the disproportionate drop of the Wernicke's aphasics in the oral condition was due to their imperfect comprehension of the stimuli. However, when the factor of auditory comprehension was introduced in an analysis of covariance, there was no significant change in the F value for the interaction between groups and conditions (F = 9.78; d.£. = 2, 19; P = .002). Post hoc t tests were similarly unchanged. Use of the severity of aphasia as a covariate also yielded unchanged
Naming to picture versus description
205
results. Comparison of the F values for the ANOV A and ANCOV A, for Total Correct and other significant measurements, are presented in Table II. The ANOVA based on the percent Correct/Total Trials in the first 5 seconds is similar to that for Total Correct and post-hoc testing of interactions yielded identical results for the two ANOVA's. TABLE II
Comparison of Significance Levels Obtained by ANOVA to Levels Obtained by Analysis of Covariance with Comprehension or Severity as Co variates
Variable
p levels by ANOVA
p levels by ANCOVA Comprehension
Severity
Total Correct/Total Trials Group Condition Interaction
.012 .001 .001
.038 .001 .002
.006 .001 .001
.015 .001 .048
.042 .001 .056
.003 .001 .048
.385 .020 .307
.467 .024 .326
.105 .020 .307
.381 .028 .354
.469 .032 .373
.102 .028 .354
0-5" Correct/Total Trials Group Condition Interaction 0-5" Correct/Total Correct Group Condition Interaction 6-30" Correct/Total Times Group Condition Interaction
Further differences between the groups and conditions were apparent when we compared short latency « 5 sec) and long latency (6-30 sec) responses (see Figure 3). Here the analysis based on the percent of correct responses produced during the given time interval was similar to that for the total correct. All groups produced a greater proportion of short latency responses to visual than to oral presentation (F = 6.40; d.f. = 1, 20 ; P = .02). That is, visual presentation came close to eliciting either an immediate response or no response for all three groups. By the same token, the proportion of long latency responses was greater under oral than visual stimulation (F = 5.68; d.£. = 1, 20, P = .03).
H. Goodglass and D. T. Stuss
206
.............. BROCA 'S APHASICS •• _,_ .• WERNICKE ' S APHASICS
~'~ """' '' ' ' ' ' ' ' ' ' ' ' 'B
80
W,
- - ANOMIC APHASICS
" .
'110 "
" ,
.... ,. "" ........... A
60
"W
CO RRECT TOTAL CORR ECT
.W
49
20
ORAL
VISU AL
0-5
0/
Fig. 3 - Comparison testing.
0/
VISUAL
Se c
short and long latency responses by type
ORAL
6-30
0/
Sec
aphasia and modality
Inspection of this figure suggests that the increased proportion of correct delayed responses to oral presentation is determined by the anomic and Wernicke's aphasics, while Broca's aphasics show almost no change between presentation modalities with respect to the distribution of immediate versus delayed responses. However, when the results were treated as coming from three separate groups, the inter-group differences did not reach significance. Consequently a series of one factor ANOVAS was used to compare the 10 Broca's aphasics and the 13 combined posterior (Wernicke's and Anomie) aphasics in percent correct delayed responses falling in the several response latency ranges under visual and auditory stimulation. Again, comparing only modality differences for all aphasics as one group, overall percent response to oral stimulation was greater than visual in the entire 6-30 second interval (F = 4.33; d.f. = 1, 22; P = .05). This was due to the fact that posterior aphasics had a greater proportion of responses to oral stimulation in each delayed response interval, although only one of these intervals taken alone (11-20 sec), gave a significant F value (F = 4.4; d.£. = 1, 21; P = .048) (see Figure 4).
Classification of subjects Multivariate discriminant function analyses comparing the three groups by either combining the two modalities of presentation in a step-wise so-
Naming to picture versus description
207 • -
BROC'A 'S APHASICS
• "... ,," POSTERIOR APHASICS
80
•
60 CORRECT TOTAL CORRECT 40
20
0-5
6~10
11-20
21-30
0-5
VISUAL
Fig. 4 modalities.
6-lIi
11-20
21-30
ORAL
Breakdown of naming responses by latency interval for visual and oral stimulation
lution or using the oral and visual measurements separately in a direct solution indicated that the groups could be significantly separated using the naming results, and that the individuals could be classified into their diagnostic categories with a high degree of accuracy. Anomies were most difficult to classify. Using the visual modality alone yielded a lower level of confidence that the classification of the patient was made correctly. These results are summarized in Table III.
Responsiveness to cueing Cues were given under the three conditions described in the methodology: (1) a visual cue was given after failure to name to oral associative description; (2) a phonemic cue was given if this visual cue failed to elicit a correct response; (3) a phonemic cue was given after failure to name to visual confrontation. Results for each cueing condition were tabulated as percentages of correct responses over the number of errors. These are summarized in Table IV. Comparisons of the responsiveness to different types of cues revealed that phonemic cueing after failure to name to visual confrontation resulted in a higher proportion of correct names than a visual cue after failure to name to oral associative description. This difference reached significance for the Broca's (t = 2.84, P < .02) and anomie aphasics (t = 2.25, P = .05). Comparison of the groups showed that, for all cueing condition, the Broca's
H. Goodglass and D. T. Stuss
208
TABLE III
Discrimination and Classification Percentages, for Three Discriminant Function Analyses
Broca
Predicted category Wernicke
Anomic
Averageb probability
Broca (10) Wernicke (7) Anomics (6)
70 (7)a (0) 33.3 (2)
20 (2) 85.7 (6) (0)
10 (1) 14.3 (1) 66.7 (4)
.717 .855 .801
Broca (10) Wernicke (7) Anomics (6)
80 (8) (0) 16.7 (1)
(0) 85.7 (6) 50.0 (3)
20 (2) 14.3 (1) 33.3 (2)
.894 .861 .651
80 (8) (0) 33.3 (2)
20 (2) 71.4 (5) (0)
(0) 28.6 (2) 66.7 (4)
Diagnostic category Combined modalities
o
o
Oral
o
o
Visual Broca (10) Wernicke (7) Anomics (6)
o
o
o
.611 .686 .730
a The values reflect the percent of subjects correctly classified into their a priori diagnostic category, on the basis of specific naming abilities. Actual numbers of subjects are given in parenthesis. b The average probability is an index of the overall confidence of the classification decision based on the measurements used.
TABLE IV
Percent Correct Responses to Cueing
For items failed on oral description Visual cue Phonemic cue Wernicke'1 Broca's Anomics
38.3 28.3 11.4
91.0 53.8 34.7
For items failed on visual confrontation Phonemic cue 76.5 44.8 27.7
aphasics responded with a higher proportion of correction to cues than both other aphasics groups, the Wernicke's aphasics having the second largest percentage. Broca's aphasics had a significantly higher proportion than did anomics for correct responses both to phonemic cues after failure to name to visual presentation (t = 3.23, P < .01) and for visual cues after failure to name to oral description (t = 2.42, P < .05). Finally, when given a phonemic cue after a visual cue had failed, Broca's aphascis were almost perfect in responding to the cue, and had a significantly higher proportion of correct responses than either anomics (t = 7.13, P < .001) or Wernicke's aphasics (t = 4.07, P < .01).
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DISCUSSION
This study was designed on the presumption that naming to visual confrontation and naming to associative description differentially evoked two different paths to the target response; that the first facilitated an immediate and direct association, while the second led to the convergence of peripheral associations to trigger the desired response. The validity of this assumption is supported by the finding that short latency responses predominated in the visual confrontation over the associative description condition, for all aphasic subgroups. It was further expected that Broca's aphasics would have relatively more success than the posterior aphasics on reaching the target response via the route of peripheral associations, but that the two groups would be more alike in response to visual confrontation. Here again the results are, at least partially, in accord with expectations. Broca's aphasics were insignificantly superior to the posteriors in naming to visual confrontation, but significantly superior to the Wernicke's group in naming to oral association. Anomics were unchanged in their total correct responses under the two conditions. A corrollary prediction, concerning the distribution of latencies was not borne out. It had been reasoned that long latency responses were an index of the extent to which naming took place via the medium of converging peripheral associations to arouse the target word, and it was expected that Broca's aphasic would achieve the greatest number of successes by this strategy. In fact, however, both Wernicke and anomie aphasics exceeded Broca's aphasics in their proportion of long latency responses under the oral association condition. However, there is no compelling reason to assume that response via peripheral assocition needs to take more than 5 seconds. The elevated proportion of delayed responses made by both groups of posterior aphasics in this condition may merely signify that they are deficient and therefore slower in responding via the peripheral associative channel. It is noted that while the anomics achieved the same total mean correct responses to oral associations as to visual confrontation, they, like the Wernicke aphasics, had a large proportion of long latency responses to oral associa tions. The most severe criticism possible for the approach used in this experiment is that the oral associative stimuli might selectively penalize the Wernicke's aphasics, who were the most deficient in auditory comprehension. However, the fact that covariance on the factor of auditory comprehension did not change the outcome would seem to answer this criticism. The oral associations used were evidently sufficiently easy auditorily so as not to influence the performance of the \Vernicke's aphasics as a function of their deficit in comprehension.
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H. Goodglass and D. T. S'uss
The present results are consistent with Barton et al.'s (1969) comparison between visual confrontation and oral description as stimuli for a naming response, in that the overall efficiency of visual confrontation exceeds that of oral definitions. However, by examining latencies and the differential behavior of Broca's, Wernicke's, and anomie aphasics we have been able to show that the relative drop in naming to auditory stimulation is due primarily to Wernicke's aphasics and that this condition also results in a large proportion of long latency responses by posterior, but not by Broca's aphasics. Facilitation of naming by cueing further differentiated between the Broca's aphasics and the two posterior aphasic groups. When cued pictorially after failure to oral associates, the Broca's aphasics responded correctly more than three times as often as the anomics. When cued phonemic ally after failure to name a picture, Broca's aphasics responded significantly more often than either of the other groups. These results confirm those recently reported by Pease and Goodglass (1978). As these authors found, the order of responsiveness to cueing by the several groups is the same as their original order of proficiency in naming. However, in the present results, the superiority of the Broca's aphasics in responding to phonemic cueing appears to be disproportionate to their superiority in naming, suggesting that a qualitative as well as a quantitative factor is at work. These results are consistent with prior evidence that the mechanism of disordered naming by Broca's aphasics is different from that of Wernicke's and anomie aphasics.
SUMMARY
Twenty-three male aphasics, classified as Broca's, Wernicke's and anomic, were tested on their ability to name objects to either visual confrontation or oral associative description. For the Broca's and Wernicke's aphasics, naming to visual confrontation was significantly better than to oral description. Broca's aphasics tended to produce more correct names than both other groups in both conditions, although significance was reached only in oral description. Differences were not significantly affected by the comprehension deficit or severity of aphasia. With picture naming, all groups tended to name immediately or not at all. For oral description, there was a greater proportion of long latency responses for the posterior patients. When given phonemic or visual cues to assist naming, Broca's aphasics benefited the most, the anomics performing most poorly. All these results suggest qualitative differences in naming ability in aphasic subgroups. Acknowledgments. The authors gratefully acknowledge Errol Baker for his assistance with the statistical analyses and Mary Hyde for the computer analysis of the data.
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REFERENCES BARTON, M. 1., MARUSZEWSKI, M., and URREA, D. (1969) Variation of stimulus context and its effect on word-finding ability in aphasics, Cortex, 5, 351-365. BENSON, D. F. (in press) Neurologic correlates of anomia, in Studies in Neurolinguistics, Vo. IV, ed. by H. A. Whitaker and H. Whitaker, Academic Press, New York. GOODGLASS, H., and BAKER, E. (1976) Semantic field, naming, and auditory comprehension in aphasia, Brain and Language, 3, 359-374. - , BARTON, M., and KAPLAN, E. (1968) Sensory modality and object-naming in aphasia, J. Speech Hear. Res., 11, 488-496. - , KAPLAN, E., WEINTRAUB, S., and ACKERMAN, N. (1976) The "tip-of-the-tongue" phenomenon in aphasia, Cortex, 12, 145-153. - , KLEIN, B., CAREY, P., and JONES, K. (1966) Specific semantic word categories in aphasia, Cortex, 2, 74-89. HOWES, D. (1967) Some experimental investigations of language in aphasia, in Research in Verbal Behavior and Some Neuropsysiological Implications, ed. by K. Salzinger and S. Salzinger, Academic Press, New York. KAPLAN, E., GOODGLASS, H., and WEINTRAUB, S. (1978) The Boston Naming Test, Boston. LURIA, A. R. (1970) Traumatic Aphasia, Mouton, The Hague. NEWCOMBE, F., OLDFIELD, R. c., and WINGFIELD, A. (1965) Object-naming by dysphasic patients, Nature, 207, 1217-1218. PEASE, D., and GOODGLASS, H. (1978) The effects of cueing on picture-naming aphasia, Cortex, 14, 178-189. ROCHFORD, G., and WILLIAMS, M. (1965) Studies in the development and breakdown of the use of names. IV. The effects of word frequency, J. Neurol. Neuros. Psychiat., 28, 407-413.
H. Goodglass, Ph. D., Psychology Service, Veterans Administration Hospital, 150 S. Huntington Ave., Boston, Mass. 02130.
