A large proportion of right-hemisphere stroke patients exhibit unilateral neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. Unilateral neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task with base-left wedge prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least two hours after adaptation. Effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of prism adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which each structure plays a specific role, though not necessarily one that is crucial for adaptation. Prism adaptation could act specifically not only on the ipsilesional bias characteristic of hemineglect but rehabilitates more generally the other spatial cognition deficits due to damage of the right hemisphere.

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We reconstructed the mechanism of impaired language domain on the basis of cognitive neuropsychology, functional imaging and the latest findings of molecular biology. Especially, we focused on syntax processing, and sentence understanding and production. The relation between FOXP2 gene mutation and specific language impairment (SLI) was investigated based on molecular biology findings. In SLI, the morphemic disorder influenced sentence understanding and production. However, SLI due to FOXP2 gene mutation was thought to be different from the dysfunction of syntactic structure generation or vocabulary selection. Subsequently, involvement of the temporal lobe in syntax processing was investigated based on the function imaging and findings of the damage brain. There was no doubt that the left frontal lobe, especially the Brodmann's areas 44 and 45, were closely taking part in the function of syntactic structure generation, vocabulary selection and grammatical morphemes acquisition. However, generation and understanding of the predicate-argument structure were assumed to originate at the semantic role of the verb, and involvement of the temporal lobe was suggested. These results gave an important suggestion for training patients with speech disorder whose chief complaint was language disorder of the grammar.

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This paper is devoted to the reconsideration of the “classical ” nosological ideational / ideomotor apraxia classification, and proposes the dissection of them from three points of view. First, it was described that the tests for apraxia and the patterns of these disorders must be carefully considered in three points : action category, input-stimulus / output combinations, and error pattern analysis. Second, Liepmann's model has been recently expanded, and apraxia could be caused by seven possible reasons. The expanded Rothi-Ochipa-Heilman's model is helpful for comprehending the patterns of disorders and the pathogenetic mechanism. Lastly, relationships between apraxia and other neuropsychological deficits were mentioned, and these other deficits must not to be excluded, but to be included for understanding the praxis-processing completely. Overall, for these reasons, ideational / ideomotor apraxia simplistic nosological classification should be practically nullified.

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Visual agnostic symptom is classically divided into two types ; apperceptive and associative type. Based on pathological visual form information process, the term of integrative type had been added to those two classical types and new classification by three types was recently proposed. Lesion analyses leveled that the bilateral medial occipital cortices are responsible for apperceptive type. Integrative and associative types are related to damage in the medial temporo-occipital cortex though it is not clear yet which part in this area is responsible for each type. Results of brain imaging studies, however, showed that activation in the lateral occipital cortex during visual form processing task. Putting together these clinical and experimental findings, it may be possible to account for those three types in terms of visual processing neural route as follows ; apperceptive visual agnosia could occur if visual information process from the medial to the lateral occipital cortex is severely damaged. If this route works partially, visual agnosia could be regarded as integrative type. Damaged in the following rostral route but not in the lateral and the medial occipital area, the symptom could be associative type. Thus by suggesting the neural route for visual form information, responsible area for each of three types of visual agnosia was explained theoretically.

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   Working memory (WM) refers to the system that comprises of the central executive and two subsidiaries or ‘slave systems ’, one of which is the phonological store for maintaining verbal information, another of which is the visuospatial sketchpad for visual and spatial information. The central executive is considered to play important roles such as supervising, integrating and processing information stored in the slave systems during the cognitive activities. The current WM model also assumes the episodic buffer which is responsible for binding information from different kinds of sources in the long-term memory (Baddeley, 2000). A functional magnetic resonance imaging or fMRI study (Prabhakaran et al.,2000) suggested that right frontal areas play an important role in integrating different forms (e. g., verbal and spatial) of information.
   This study investigated how the normal subjects and a patient with a right frontal lesion performed on tasks regarding the maintenance of integrated information derived from two different domains. The nature and mechanisms of memory binding were discussed.

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Depression is a common neuropsychiatric consequence of stroke. Apathy is also often observed after stroke and is defined as reduced motivation or lack of initiative and motivation, and used commonly in the neurological field. However, in psychological field, apathy (loss of interest) is thought to be a partial symptom of depression. In this way, depression and apathy has been confused from department to department. Previously we examined neuroanatomical finding as concerned with the depressive and apathetic dimensions of post-stroke depression (PSD) separately, demonstrated that the severity of depression (SDS score) was associated with left frontal lobe (but not basal ganglia) damage, and that of apathy (AS score) was related to damage to the bilateral basal ganglia (but not to the frontal lobe) . We also examined the effect of depression and apathy on the functional recovery after stroke, suggested that the apathy was a predictor of poor functional recovery after stroke. Thus it is thought that after a stroke there are two separate core symptoms (“ depressed mood ” or “ loss of interest ”) with different underlying neuroanatomical mechanisms. After stroke, emotional response is also important factor for understanding the mechanisms of the post-stroke depression. Insistence on recovery is thought to be a sign of denial and thus is regarded as an irrational belief. However, our previous study demonstrated that the appropriate level of insistence on recovery reduced depression and apathy, resulting in enhanced improvement of disability after a stroke. When caring for patients, we should inform them of their prognosis in such a way that they do not give up hope.

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This paper discusses the required inspection procedures for evaluation of higher brain function. In order to obtain the accurate status of a patient, an appropriate inspection, a detailed observation and a correct interpretation of it are necessary. For higher brain dysfunction, it is a matter of importance that not only results of neuropsychological test should be shown but also the processes during which how a patient reacts specifically to what issue should be grasped. Among other things, the most important approach is to listen attentively to opinions of patients' family members with the patients' daily living and social life in view.

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In aphasia speech therapy, it is important to stimulate brain to reorganize involved functions. However, aphasic syndrome includes various symptoms which should be not only stimulated, but also be inhibited (such as jargon, perseveration, and so on). The purpose of speech therapy is to achieve the improvement of linguistic competence and communication skills. To aim to reorganize brain functions and to improve communications skills of aphasics', speech therapists would be required to compose flexibe and smart interactive communications with aphasics. That is, appropriate “stimulation (or inhibition)-reaction” might bring effectiveness of speech therapy.

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   This study investigated the regions of brain damage affecting prospective memory (PM) in patients with traumatic brain injury (TBI). The subjects were 55 TBI patients who had sustained brain contusions and intracerebral hematomas involving the prefrontal cortex and the temporal lobe. The self-initiated PM task described by Umeda et al (2000) was used to evaluate PM. Based on the results of the PM task, patients were classified into 2 groups : (1) the group able or unable to remember the intention to remember, and (2) the group able or unable to remember the contents of the intention. Furthermore, all instances of damage to areas of the frontal lobe (dorsolateral, ventrolateral, medial, and orbital) and the temporal lobe (lateral and medial) were totaled. The influence of each brain lesion on the results of the PM task was analyzed using discriminant analysis.
   The results of the analysis were as follows. (1) The brain lesions with the greatest effect on remembering the intention to remember were those of the medial temporal lobe (MTL), followed by those of the medial frontal lobe (MFL). (2) The brain lesions with the greatest effect on remembering the contents of the intention to remember were those of the MTL, followed by those of the dorsolateral frontal and lateral temporal lobes ; the influence of the MFL was low.
   These results suggest that the MTL contributes most to both remembering the intention to remember and remembering the contents of the intention to remember, and that each region of the frontal lobe differs in degree of involvement in remembering.

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Recent neuropsychological and neuroimaging studies have suggested that faces were “ special ” for the human visual system. In this argument, a case of prosopagnosia without object and picture agnosia who had a highly specific deficit for faces, could provide the critical evidences, because many prosopagnosic patients have some difficulties with the visual processing of non-face stimuli such as objects. In the present study, we reported the case of 69-years old right-handed female who was unable to recognize faces whilst retaining the ability to recognize other objects after damages to bilateral lateral occipital cortex including occipital face area (OFA) and right lateral fusiform gyrus involving fusiform face area (FFA). She complained of difficulty in recognizing familiar faces. The results of Visual Perception Test for Agnosia (VPTA) suggested a restricted problem in the face recognition. Her ability to name line drawings of common objects and photographs of famous buildings is intact. Verbal biographic information of famous people was also preserved. She had no deficits of retrieving the name and semantic information of famous people from the verbal stimuli. Her performance on the naming test with visual modality (used face photographs) was remarkably decreased. These results demonstrated that she was a case of pure prosopagnosia. She could distinguish and recognize unfamiliar faces without external features such as hair, suggesting the intact perceptual process of faces. Thus, this patient had associative prospagnosia (De Renzi et al.,1991) without object agnosia, which indicted that faces were “ special ” for visual recognition in human. Furthermore, the lesion analysis suggested that damages to occipital face area (OFA) have a critical role in the development of pure prosopagnosia.

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In order to consider rehabilitation for disorders of tool use, we assigned 20 kinds of tool use tasks to 16 right-handed, left brain-damaged patients with disorders of tool use, and attempted to classify them by error type. Furthermore, we considered the relationship between error types and tool feature and associated lesion. Based on tool use process, errors were divided into 8 types : I : understanding of tool use, II : movement preparations, III : way of holding, IV : target choice, V : temporal sequence, VI : way of tool manipulation, VII : effect verification, and VIII : recognition of the end. The findings suggested that the number of errors depended on tool features such as high-frequency use, recognition of dangerous materials, and the appearance of the tool. Understanding of tool use error appeared with all tools, but errors relating to way of holding and way of manipulation were thought to be influenced by tool shape. We found relationships between error types and lesions : I : temporal lobe, III : basal nuclei, V : communication tract to frontal lobe, and VI : parietal lobe. We concluded that adopting the method suitable for the tool use disorder which could be supposed from the lesion would advance rehabilitation of tool use disorders one step further.

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Perceiving one's own bodily state had been proposed as the origin of feeling emotions. Insular cortex is considered to play a critical role in integrating interoception (perception of the internal bodily state) and perception of on-going environmental information regarding emotions. This brain region is also known as the neural substrate of recognition and experience of disgust. In the present study, we compared emotional processing abilities for a male patient A, who had right anterior insular damage due to viral encephalitis. The photographs depicting facial expressions were presented to this patient and age-matched controls, and they were requested to make judgments for the categories and intensities of the facial emotion on each picture. During the judgments, skin conductance responses (SCR) were recorded to examine how the insular damage affects regulation and perception of internal bodily states. Although patient A showed correct judgments on happy and neutral faces, he had difficulties to discriminate negative facial expressions such as angry and disgust. Furthermore, patient A underestimated the intensity of the angry faces compared with controls. However, we observed no significant differences on SCR to facial expressions between Patient A and controls. These results indicate that the right insular cortex is not unique to recognize disgust, but have an important role to discriminate the negative emotions in general. Our findings also support the notion that this area is the critical for receiving internal bodily states and interpreting the sensation to make subjective feeling.

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