Clinical Validation of an Auditory Language Comprehesion Test for Aphasia: a Quantitative and Qualitative Study on the Token Test

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A full length version of the Token Test (Japanese edition) and WAIS were adminstered to 32 aphasics, 23 non-aphasic brain-demaged patients and 20 controls. The diagnostic aphasia test (SLTA or Rohken's) was also administered to aphasic patients. The results are as follows :1) The Token Test could discriminate satisfactorily between aphasic and non-aphasic brain-damaged patients. On the cut-off score of 48 (lowest score shown by the control group) in the pass-fail scoring, 89.1% of all the patients were correctly classified while 6.2% of the aphsic patients and 17.4% of the non-aphasic patients were classified incorrectly.2) In the control group the influence of age and IQ on the Token Test scores was investigated. No significant correlation was found. On the other hand, in the aphsic and the non-aphasic groups some significant correlations were found : in the non-aphasic group a moderate influence of VIQ (at the time of examination) on the Token Test scores was found ; in the aphasic group a slight influence of age (negative correlation), and moderate influence of VIQ and PIQ (at the time of examintion) on the Token Test scores were found.3) In Parts (I-V), semantic errors were examined concerning shape, color, and size. In the aphasic group the highest error rate was shown with shape, the second with color and the least error rate with size. In the other two groups, those error rates were less than those concerning size made by the aphasic group. Syntactic errors were committed more frequently than semantic errors in Part V. The aphasic group had higher error rates than the other groups. But, the patterns of difficulty the aphasic group felt were similar to those the other two groups felt trying to respond correctly to each item of the Test.4) In the aphasic group significant correlations were found between the Token Test scores and the scores of both auditory comprehension ability and speaking ability assessed by the differential diagnostic aphasia test.The Token Test seemed to have about the same discriminating power in an Italian, an English, a German and a Dutch speaking group of neurological patients.And, it was demonstrated that there was a close relationship between the severity of aphasia and the Token Test score. The implications of these results were also discussed.