Previous studies on the so-called language learning skill of chimpangees were briefly reviwed and discussed. Backgrounds why we trained three young chimpangees to use lexigrams through a matching-to-sample method were explained. A skill to name 25 different colored objects developed without previous experience at requesting particular objects using the lexigrams. Future plans to study the brain mechanisms related to language acquisition are briefly mentioned.
Left-sided unilateral spatial agnosia has been considered to be a symptom which is produced by the damage in the right temporo-parieto-occipital junctional area. A regional cerebral blood flow (CBF) study was performed on 3 patiets having left-sided unilateral spatial agnosia by single photon emission computed tomography (Emission CT). Localization of lesions have been discussed. Case 1 : a 69-year-old right-handed man. A CT scan revealed an area of low density in the total territory of the right middle cerebral artery. An Emission CT showed reduction of CBF in its territory including the temporo-parieto-occipital junctional area. Case 2 : a 65-year-old right-handed woman. A CTscan showed right putaminal hemorrhage. An Emission CT revealed an ischemic area of the putamen with a surrounding white matter. It also shows an ischemic area of the posterior parietal lobe and the parieto-occipital junctional area. Case 3: a 70-year-old right-handed woman. Cerebral angiography showed the right posterior cerebral artery occlusion in its crural segment. A CTscan revealed an area of low density in the right thalamus and medial portion of the occipital lobe. An Emission CT showed, however, a reduction of CBF in the total area of the right posterior cerebral artery including the parieto-occipital junctional area. Localization of lesions common to the 3 patients obtained from the Emission CT is the right parieto-occipital junctional area. This area is suggested to have been the site of lesions producing left-sided unilateral spatial agnosia.
Standard Language Test of Aphasia (SLTA) and regional Cerebral Blood Flow (rCBF) measurement were performed in patients with aphasia fllowing hypertensive intracerebral hemorrhage and cerebral infarction. Relationship between severities of the several elements of SLTA, mean CBF and rCBF patterns were investigated and its results were as follows. 1) Relationship between correct answer rate of SLTA and mean CBF revealed various patterns: elments which contain complexed procedure showed low rate of correct answer, but one with simple procedure disclosed high rate of correct answer. However these elments did not show correlations between mean CBF, while elements with moderate procedure revealed positive correlations to mean CBF. 2) According to the percentage of correct answers in SLTA, the patients with aphasia were divided in four grades, and the following results were obtained. i) The I grade group showing more than 76% of correct answers revealed a hyperfrontal pattern in all the elements, i. e. hearing, speaking, reading, writing, and calculation. However this hyperfrontal pattern was not noted in patients with cerebal infarction at all. In IV grade group, hypofrontal pattern was seen, however it was noted only in reading. ii) If the correct answers in SLTA were less than 50% (III and IV grade groups) critical CBF was estimated to be below 25ml ˜ 20ml / 100g brain / min of mean CBF. 3) Factors which have greater influence on critical CBF were as follows: the localized sits as well as extensiveness of focal ischemi, in the latter, the inclusion of speech center or speech zone is particularly important.
Thirty-five aphasic patients and ten right brain damaged patients were given two sets of test of semantic-lexical discrimination. One is consisted of five words belonging to the same category (SCT), the other is five words of the different categories (DCT). Main results are as follows: 1) Statistical control showed that a significant difference existed between aphasic group and right-brain-damaged group on both tests. 2) The difference between correct responses in SCT and in DCT in aphasic group reached the level of statistical significance. 3) Aphasic patients who had gained high score on DCT but low score on SCT examind within three months from the onset showed poor recovery in auditory tasks of SLTA there after, on the other hand, subjects who had gained high score on SCT showed much recovery. 4) SCT showed high correlation with the subdivision of auditory command in SLTA, where as DCT highly correlated with the subdivision of a short sentence in SLTA. 5) SCT may indicate the prognosis of auditory comprehension for aphasics. 6) SCT wonld be useful as a deep test of SLTA.
We developed a new method of cortical audiometry using non-filtered Japanese CV monosyllables selected from a phonological standpoint. The test materials were recorded on magnetic tape and presented to the ear through a receiver at 50 dB above the patient's subjective threshoh at 1000 Hz. Fourty subjects including six with motor aphasia, nine with sensory aphasia, six with lesions of the right temporal lobe, nine with moderate sensorineural hearing loss and ten normal adults were tested by our method. The results obtained were as follows: 1) The discrimination of the monosyllables was poorer in the ear contralateral to the lesion of the temporal lobe. 2) Discrimination errors appeared primarily in consonants, and discrimination errors of the vowels were limitted to the patients with sensory aphasia in whom discrimination of the monosyllables was severely impaired. 3) The most prominent discrimination errors of the consonant observed in every case was confusion to/r/. 4) The syndrome of sensory aphasia was classified into two groups by qualitatively different responses obtained on our test. Specifically for one group, discrimination errors occurred primarily on the phonetic or auditory level, while for the second group discrimination errors occurred on the phonological level.
Musicians and nonmusicians were tested in the recognitions of four kinds of dichotically presented music stimuli : recorded tones, chords, rhythms and melodies. Nonmusicians were 18 subjects (A), who worked in fireman's agency in Paris, France, whose ages ranged from 18 to 28 years (average : 20.2 years) and whose years of musical experiences ranged from 0 to 5. Musicians were 8 students in musical college (Conservatoire national supérieur de Musique de Paris): 5 right-handed (B) and 3 left-handed persons (C), whose ages ranged from 18 to 25 years (average : 21.8 years), whose years of musical experiences ranged from 10 to 18 (average: 12.8 years). 1) In the tone test, the mean score for right and left ears were nearly the same for both A and B. 2) The chord test revealed a significant left ear superiority for A, and the tendency of the higher score in left ear was seen for B. 3) In the rhythm test, the score for the right ear had a tendency to be higher than the one for the left ear, both in A and B. 4) In the melody test, the score showed a tendency of left ear superiority for A, but the tendency of right ear superiority was seen for B. Bever and Chiarello (1974) found a right ear reference in the detection of musical stimuli when they used musicians as subjects. Johnson made the dichotic listening task involving violin for musicians and nonmusicians. The musicians demonstrated a right ear superiority, while the nonmusicians performed better with the left ear. He interpreted that musicians mainly used the left hemisphere to process musical stimuli, while nonmusicians used the right hemisphere. The results of Bever and Chiarello, and Johnson nearly agree with the results of our musical dichotic listening test for nonmusicians and musicians in France as well as the results of our former studies for pupils of chorus club in elementary school, stdents of philharmonic club in senior high school and students in musical college in Japan.
A case of 58-year-old Japanese-Korean bilingual presenting alexia without agraphia was studied. Clinical diagnosis of cerebral infarction in the left occipital lobe was confirmed by neuroradiological examinations. Although his native spoken language was Korean, he was educated in Japanese language at school. He spoke both the Korean and the Japanese very fluently, but was barely able to read and to write the Korean until 48 years old, when he began to study them. He mastered them quickly, and his abilities of reading and writing the Korean were the same level as the Japanese before the present illness. Although his reading was impaired in both languages, the degree of impairment was more severe and the recovery was more delayed in the Korean than in the Japanese. The rules of Ribot and Pitres in polyglot aphasia can be applied for the recovery pattern in the present case. There is no established explanation for those discrepancies between languages in polyglot alexia without agraphia. As long as the mechanism of this syndrome is explained by the visualspeech disconnexion, it is unlikely that complexity of graphemic system takes a part in presenting those discrepancies. It seems likely that several different philological factors may contribute to produce the discrepancies between languages in alexia without agraphia of polyglot, like in aphasia.
We have compared the aphasia, apraxia, and agnosia in nine cases of crossed dextral aphasia ( CDA) and six cases of sinistral aphasia(SA). The control group was twenty-two cases of dextral aphasia with mirror image lesion (CT scan) of respective CDA. The common prominent aphasic syndromes in CDA and SA were agrammatism and good naming ability. According to Hécaen and Brown(1976), CDA differs from SA in the frequency of agrammatism, anomia, and phonemic paraphasia. However, with regard to these syndromes, Our cases did not exhibit such a difference. For three cases of CA, the relation between the caudality of lesional localization (CT scan) and the types of aphasia diverged from that of DA, i. e., they displayed Wernicke's aphasia by anterior lesion or Broca's aphasia by posterior lesion. Therefore, localization of language function in CDA did not seemed to be the mirror image of DA. As to apraxia and agnosia, both dominant and non-dominant hemisphere syndromes were seen in aphasics of right hemisphere lesion. This could be interpreted that in these patints., functions of the left hemisphere overlapped, never reversed, with those of the right hemisphere.
Disorders of speech and other mental functions in eight patients with left thalamic hematoma were examined, both in their acute and chronic stage. The examinations in the acuts stage revealed a decrease of vigilance in 7 cases, fatiguability in 6 cases, a paucity of spontaneous speech in 6 cases and small vocal volume in 5 cases. In addition, 6 out of cases exhibited some speech disorders, inluding paraphasia, word-finding difficulties, circumlocution. The other two cases showed memory dis turbance and / or disorientation. Fluency, repetition and comprehension were well preserved in all cases. And, in the chronic stage, disor ders of speech and other mental functions almos disappeared in 7 cases out of the 8. Those defects were not considered as being aphasia, but as a lack of activation of higher mental functions in the dominant hemisphere.