This article examines the nature of syntactic disorders in agrammatic aphasics from the viewpoint of current linguistic theory, i. E. the generative grammar (Chomsky, 1993, 1995). It is shown that Hagiwara (1995) 's generalization on grammatical disorders, which state that the lower the functional projections are, the more accessible they are to an agrammatic aphasic, has been replicated by the experiments on many languages including Hebrew, Arabic, Dutch, and French and that cumulative evidence shows the validity of the hypothesis. The explanation of this phenomena is proposed in Hagiwara (1995) in that agrammatics's grammar allows convergence, i. E. successful computation at lower functional projections, because such structure are less costly from a global economy perspective (i. E. comparing different syntactic derivations : Chomsky, 1993). We maintain that this Economy Principle on agrammatism is more highly adequate than the other proposals with respect both to its coverage of the modality of patients' performance and to the level of explanatory adequacy. The last part of this article discusses the assessment of grammatical disorders along the line of hierarchical syntactic structures and its application to language therapy.

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    In this paper, first, we introduced our results of two fMRI studies : sentence comprehension task and prediction task of action sequence. Second, we considered the role of the loop between frontal and parietal cortex. Our results suggested that image generation and manipulation for articulation and hand movement is implemented by this loop. For sentence processing, articulation and internal auditory image was generated by the forward and backward transformation of information between Broca's area and supramarginal gyrus. On the basis of the processing, syntactic knowledge, stored in Broca's area and precentral gyrus, and semantic information, retrieved by the interaction between BA 45 and temporal cortex, are integrated. Furthermore, image generation and manipulation for sentence understanding would be implemented by the interaction among dorso-lateral frontal lobe, supplementary motor cortex, intra-parietal sulcus, and inferior parietal lobe. Finally, it was shown that this model could be interpreted on the extensive framework of the motor sequence prediction hypothesis.

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    It is thought that verb deficits are always associated with syntactic agrammatism, and cause sentence comprehensions and productions. This association led us to adominister two speech therapies centering upon verbs to two subjects (AK and AH) with syntactic agrammatism. The first one is verb therapy, which aims to facilitate the verb comprehension and the verb production. Another one is mapping therapy, which aims to identify the thematic roles decided by a verb and to map them to the syntactic structure. The result showed that AK didn't so benefit by both therapies. This was thought to be caused by the fact that AK's aphasic disorders might be generally sever too much. AH benefited by both therapies ; verb therapy being more effective than mapping. The first resulted in better verb retrieval and improved sentence production with verbs. The second resulted in improved sentence production with verbs. These improvements were considered not to be caused by spontaneous recovery nor by activeness of general language faculties, but by effectiveness of each therapy.

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    Although the recent brain activation studies utilizing positron emission tomography (PET) have provided important neurophysiological informations concerning the functional neuroanatomy of language processing, the results of those studies differed each other possibly due to the variability in the paradigm designs. This article reviews the results of selected PET activation studies using verb generation tasks based on the right-handed normal subjects in the past 10 years. In the verb generation tasks, subjects were asked to think of verbs as many as possible which are associated to the visually or auditorily given nouns. Resting state or word repetition was often used as control condition. The image subtraction of the control condition from the verb generation demonstrated consistent activation foci in the left middle frontal gyrus, inferior frontal gyrus including Broca's area, anterior cingulate gyrus, superior temporal gyrus including Wernicke's area, and supplementary motor area, whereas there were less consistent activation foci in the insula, parietal cortex, thalamus and basal gagnlia on the left hemisphere. Activation foci were also seen in the right frontal, temporal and occipital cortices although the degree of activation was less significant as compared to the left hemisphere. In the infratentorial structures, activation was observed in both cerebellar hemispheres with a predominancy of the right side, vermis and brain stem. From the results the previous studies, retrieval of verbs in response to the presentation of nouns reuuired activation in the extensive brain areas involving the left frontal and temporal lobes as well as cerebellar hemisphere. There was no significant difference in the activation patterns for verb generation in Japanese language as compared with English or other European languages. This may indicate that the verb generation processing shares fundamentally the common brain areas regardless of language.

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    Recent development of neural networks for reading words, such as the framework called the “triangle model” proposed by Seidenberg and McClelland (1989) , makes it possible to simulate reading processes of not only normal subjects but also patients with various dyslexia (or alexia) like deep, surface and phonological dyslexia. In this paper I first describe the outline of dual route models, as opposed to the triangle model, which possess lexical and non-lexical (rule) systems. Then, I will give a general description of a single route model (the triangle model) , e. G., the network's constituent “unit,” the basic structure of a three-layered feedforward network, a learning procedure called back propagation, etc. This type of a model is called the connectionist model. Interestingly, the neural network has a high ability to read words and nonwords despite of its simple structure, and it sometimes shows unpredictable behaviors due to intuition. While most research is being done in English speaking countries, it has been shown that, even in Japanese which has a more complex character system than English, the triangle framework can simulate performances on reading of Kana and Kanji words and nonwords in normal and dyslexic people. Moreover, it is mentioned that the point at issue is not in the number of routes of the models but in the “rule/lexicon” vs. “consistency” for reading. The challenge of the connectionists against the rule/lexicon approach is now made for spelling, verb inflection (generation of past tense of verbs) , and generative grammar (the stronghold of the rule/lexicon approach).

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    A Test of Lexical Processing in Aphasia (TLPA) was developed by the Japan Logopedics and Phoniatrics Association Committee on Speech and Language : Subcommittee on Aphasia. It forms the core of a battery that has been developed to the present. It consists of lexical decision tests (visual and auditory), noun and verb tests (naming and comprehension), synonym judgment tests (visual and auditory), and a test of nouns in ten semantic categories (naming and comprehension). The TLPA is designed to assess closely the performance of lexical processing in patients with brain damage. We have already reported its outline and the performance of 50 non-brain-damaged normal subjects.
    In this paper, lexical deficits in aphasic patients were analyzed with TLPA. In result, (1) the dissociation in functions of processing phonology, orthography and meaning, (2) specificity of naming and comprehension in semantic categories in nouns, (3) and specificity in grammatical classes of word (nouns and verbs) were verified. TLPA should be a valuable resource for analyzing characteristics and underlying mechanisms of lexical deficits in aphasic patients, planning their treatment programs and measuring efficacy of the treatment.

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    The functional brain imaging techniques have potential for making major contribution to understanding of the functional organization of the human brain involved in cognitive function. The combination of at least two imaging modalities, e. G. functional MRI and EEG, can achieve sufficient both temporal and spatial resolutions to identify specific brain network involved in cognitive tasks. In this manuscript, I will present some of the results from our recent functional imaging studies investigating human brain activity in relation to the recognition of familiar faces, and to the auditory processing of onomatopoeia.

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    To clarify the nature of deficits in verbal short-term memory in brain-damaged patients, weexamined two patients with mild aphasia. Case 1 had transcortical aphasia after damage to the Broca's area and case 2 had conduction aphasia after temporo-parietal lesion. Both patients showed almost the same performances in the forward digit span task and various subtasks for single words in the Standard Language Test of Aphasia (SLTA).
    The following four tasks were used : a serial word repetition task, a serial pointing task from auditorily presented words, a serial oral recall task, and a serial pointing task from visually presented words. Case 1 exhibited graver impairment in the serial pointing task than in the serial word repetition task from auditorily presented words. She also showed impairments in the two tasks in which stimuli were presented visually. By contrast, case 2 demonstrated no differences among all the four tasks.
    These results indicate that impaired processes in verbal short-term memory are different between case 1 and case 2. Case 1, who had damage to the left frontal lobe, may have impairments in the semantic storing system or in translating plural stimuli from the phonological short-term store to the semantic storing system, as well as in phonological recoding from the visual short-term store. The impairments of case 2, who had damage to the left temporo-parietal lobe, may reflect reduced capacity of the phonological short-term store, despite ability to translate phonological information to the semantic storing system.
    We propose a model in which there exist two parallel storing systems for verbal information in the human brain : a phonological loop and a semantic short-term store.

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    A 46-year-old right-handed Japanese woman demonstrated right grasp reflex and right compulsive manipulation of tools associated with cerebral hemorrhage. Magnetic resonance imaging revealed a lesion involving the medial aspect of the frontal lobe, part of the anterior cingulate gyrus, and the body of the corpus callosum on the left.
    It was notable that the patient's grasp reflex and compulsive manipulation of tools occurred without damage of the supplementary motor area. Her compulsive manipulation of tools was triggered by obsessive intent to use the objects against her will.
    The mechanisms behind these signs and symptoms were speculated as follows. Her grasp reflex and compulsive manipulation of tools may be the result of damage to the pre-supplementary motor area in the left frontal lobe. We speculate that neural disconnections between the thalamic and motor areas in the left frontal lobe are crucial for producing grasp reflex and compulsive manipulation of tools.

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