Recent advancements in functional imaging have revealed two information streams. In repetition/auditory comprehension, a dorsal route plays the part of phonology to articulation conversion, travelling through the arcuate fasciculus, whereas a ventral route plays the part of phonology to semantics, proceeding from the superior temporal gyrus to the orbitofrontal gyrus via the uncinate fasciculus. In reading/written comprehension, on the other hand, the authors suggested another dual-route: a dorsal route goes from the visual cortex to the posterior superior temporal gyrus, and converts graphemes to phonemes successively, whereas a ventral route goes from the visual cortex to the posterior inferior temporal cortex, and plays the part of whole-word recognition. Besides, in writing to dictation, the authors proposed the other dual-route hypothesis: a phonological route conveys phonological information on words proceeding from the auditory cortex to the frontal lobe via the arcuate fasciculus, whereas an orthographic route conveys orthographic images of words, going from the posterior inferior temporal cortex to the frontal hand area through the parietal lobe. These dual-route hypotheses should be validated further with the development of neuroimaging techniques.

Evolutionary neuropsychology is an integrative research field of the various cognitive functions of human beings based on classical neuropsychology, developmental neuropsychology, cognitive archaeology and comparative animal behaviology, etc. The present article is a study of art, which is a specific behavior unique to human beings, basing upon the evolutionary neuropsychology of drawing behavior.

The first half of this article outlines the history of discussion about the fluent/non-fluent dichotomy for aphasia, which is an issue that can be traced back to Jackson or Wernicke in the late 19th century. Researchers realized that there were two types of aphasia: one in which speech is mostly or completely lost (speechlessness), and one in which errors occur in the use of words despite an abundant vocabulary (defective speech). During the 1960s and 1970s, the concept of fluency in aphasia was clarified by Boston scholars, and the discussion evolved to include typology that mainly divided aphasia into fluent aphasia and non-fluent aphasia on a scale. At that time, the fluent/non-fluent dichotomy attracted considerable attention because the site of the lesion could be approximately estimated. On the other hand, some researchers opposed the adoption of this dichotomy, such as Poeck. While the importance of fluency in aphasia was being debated, Jakobson (1963) proposed a linguistic solution, suggesting that two basic linguistic operations (referred to as "selection" and "binding" ) divided the speech pathology of aphasia into two parts. Jakobson proposed that disorders of selection corresponded to aphasia and disorders of binding corresponded to expressive aphasia. This perspective is still important today when conducting qualitative evaluation of aphasia. Based on the discussion in the first half of the article, the second half addresses problems with categorizing aphasia as fluent/non-fluent from the perspective of treating patients. Using four cases as examples, it is suggested that speech training for patients referring to disability structures cannot necessarily be planned appropriately when actual patients are evaluated by using a fluency scale. For Case A, there was a problem with comprehensive assessment due to debate over evaluation because inner speech was fluent, while narrowly defined speech demonstrated non-fluency due to anarthria. With regard to Case B, even though the disability structure remained the same, the profile showed a transition from "non-fluent" to "fluent" over the course of time. Case C was considered to be non-fluent based on factors associated with other inner speech, even though anarthria was not observed. Case D had transcortical sensory aphasia due to an anterior lesion, raising the issue of "fluency evaluation" as a method of estimating the lesion location. In summary, the underlying mechanism that leads to fluency/non-fluency of a patient's speech needs to be clarified to plan speech training correctly, because the training adopted may vary depending on the details of the mechanism. Quantitative evaluation based on a "fluency scale profile" can be useful for general understanding of the clinical picture. However, it is essential to advance further to qualitative evaluation for performance of rehabilitation. The fluent/non-fluent approach to aphasia might well have outlived its usefulness in the current environment, particularly when speech training for patients is planned, although the fluent/non-fluent dichotomy remains historically significant.

In order to explore the essential deficits which cause the non-fluent speech in aphasic patients with anterior cerebral lesions, recordings of speech samples and neuroimaging data in the transcortical aphasics due to frontal lobe damage were retrospectively reevaluated. Mesial frontal lobe lesions caused transcortical motor aphasia with severe aspontaneity of speech. Dorsolateral frontal lobe lesions were divided into two types. If the lesions spread anteriorly into the anterior portion of frontal lobe such as frontal pole or orbital portion of the inferior frontal gyrus, they caused typical transcortical sensory aphasia with fluent jargon-like speech backed by euphoria, inattention, and disinhibition. In cases with focal dorsolateral frontal lobe damage, some patients showed severe non-fluent speech with much hesitation and discontinuation. Their ability of naming objects were relatively preserved, and therefore, the association between meaning and lexical items was presumed to be spared. They were not able to, however, select one of multiple competitors all of which are properly activated, nor align them in good order. I speculate that severe non-fluent speech is attributable to the impairment of selection and sequencing that are served by dorsolateral frontal lobes.

Apraxia of speech (AOS)/anarthrie is a motor speech disorder characterized by core symptoms of distorted articulation and segmentation of syllables. However, little is understood with regard to the nature of AOS. We explained the neuropsychological and neuroanatomical features of patients with stroke-induced pure AOS (sAOS), patients with primary progressive apraxia of speech (PPAOS), and normal control adults. Based on the previous reports, all patients with sAOS could be classified into four subtypes: type I with prominent distorted articulation; type II with prominent segmentation of syllables; type III with similarly prominent distorted articulation and segmentation of syllables; or type IV with prominent distorted articulation and no signs of segmentation of syllables. In the investigation of PPAOS using the same methods as the above report, PPAOS with prominent distorted articulation. However, it was only PPAOS that the reduction of speech rate was prominent even though segmentation of syllables was not remarkable. The lesions of a patient with type I was located in the left precentral gyrus, type II in both the left precentral gyrus and left premotor cortex, type III in the white matter of the left periventricular region, type IV in the white matter of the left periventricular region and left striatum. Patients with PPAOS demonstrated significant reduction of regional cerebral blood flow in the left superior premotor cortex and bilateral supplementary motor area. We speculate that a focus on the contrast between distorted articulation, segmentation of syllables, and speech rate could be useful for sub-classification of AOS.

The foreign accent syndrome (FAS) is a rare speech disorder characterized by the emergence of foreign accent. Until now, more than 100 cases of FAS have been reported and the impression of accent change is regarded to be the result of a combination of segmental deficits (i.e., phonetic distortions and phonemic paraphasias), and supra-segmental changes (i.e., stress, pitch, or rhythm variation known as disprosody). The most common etiology for FAS involves a stroke, followed by other causes. As for the anatomical substrate for FAS, most of the cases involve the lesion in the left frontal lobe, especially in the left pre-central gyrus. However, various lesions were reported to develop FAS, including the right hemisphere, the brain stem, and the cerebellum. Because of such a heterogeneous etiology and lesion location, it is controversial whether there is consistency or universality enough to treat it as a "syndrome".

Here, we reviewed the literature of FAS with a neurogenic origin to elucidate the characteristics and mechanism of FAS. As a result, we suggested that the Japanese FAS cases could be classified into two subtypes, i.e., the "English accent type" and the "Chinese/Korean accent type" depending on the types of speech error. In addition, the lesion network mapping analysis using the lesions of the previous FAS cases without aphasia suggested that the common disrupted functional network might be localized to the middle portion of the precentral gyrus, known as the larynx / phonation area.

A 79-year-old right-handed man who is a retired accountant developed alexia specific to single kana (syllabogram) letters following a cerebral infarction in the left medial occipitotemporal region. Neurological examinations revealed right upper quadrantanopia, alexia, agraphia, and color anomia. The patient could read kana words and kanji (logogram) words correctly but not a single kana letter or kana non-words. Tracing a kana letter with his finger did not improve his reading performance. Following the auditory presentation of a syllable, the patient was unable to point to the corresponding single kana letter. He also had difficulty writing kana letters that overlapped with those he could not read. Thus, his ability to read and write single kana letters was severely impaired, whereas his ability to read kana words was preserved. These findings suggest that the patient retained intact word forms but had impaired representations of kana letters. He may be able to read kana words using word forms as a whole, even though he cannot read individual letters with confidence.

Patients with Alzheimer's disease exhibit memory disturbance from an early stage, and later show difficultly using everyday objects. In addition, their impaired usage of electrical appliances is drawing attention. In this study, we conducted two investigations of Alzheimer's disease outpatients:an investigation into their ability to use everyday objects, and the evaluation of a task using a simple television remote controller (remote-control task).

In the initial investigation of their ability to use everyday objects, the patients frequently showed difficulty using electrical appliances, especially a television remote controller.

In the remote-control task, one quarter of the Alzheimer's disease patients showed an incorrect usage. The Alzheimer's disease patients could push the buttons of the remote controller without any difficulty, and the score of the remote-control task was also correlated with that of the MMSE. Overall, the results suggest that impaired remote controller usage is associated with the severity of dementia and another non-apraxic factor.