Since there are accumulating evidences to show that Homo sapiens neanderthalensis could possibly speak in a primitive way, the author have proposed the term “Homo loquens” as the name of animal family including Homo sapiens sapiens and Home sapiens neanderthalensis. Recent technological advances have enabled us to investigate more accurately than ever the neural organization of the brain of Homo loquens. Through the clinico-anatomical correlation studies of the patients combined with the functional imaging studies upon normal subjects, cortical areas responsible for certain aspects of language functions have been discovered other than classical language areas. One of these areas is the left inferior temporal area including Areas 38, 21 and 37 of Brodmann which is now thought to be the cortical area of lexicon. Another new-face cortical area participating in the language function of Homo loquens is the left posterior inferior temporal area which was revealed to be the crucial cortical area responsible for semantic reading process. On the other hand, the role of the left angular gyrus which had been regarded as the center of reading and writing is now to be seriously doubted, because our PET activation studies revealed thet the cortical area which is activated while reading phonograms is not the angular gyrus but the left lateral occipital area.

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    We reported a case of peculiar reiterative speech following encephalitis. The patient was a right-handed male who had been afflicted with encephalitis when he was 22 years old. When we examined him about 7 years later, he suffered consciousness-impairing seizures several times a day. He also showed apathy, unawareness of his deficits and a tendency toward dysinhibition. MRI revealed atrophy in the right fronto-temporo-parietal lobe and left temporal lobe, and enlarged lateral ventricles especially in the right hemisphere. In neuropsychological evaluation, he demonstrated aphasia and auditory agnosia (word deafness, sound agnosia and amusia) and reiterated his speech quite frequently. The characteristics of his reiterative speech were as follows : a) the most frequent repetition unit was one syllable, followed in descending order by single words and multi-syllables ; b) repetitions were frequent at the last and middle syllables of words, while less frequent at the first syllable. We suggested that his reiterative speech may be mostly closely associated with logoclonia, and that logoclonia is not a symptom manifested only in patients with Alzheimer's disease.

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    We reported a case of Gerstmann's syndrome and discussed one of four points at issue concerning Gerstmann's syndrome as summarized by Benton (1992) : whether the combination of the syndrome's four symptoms is behavioral expression of a single underlying basic deficit (Grundstorung). The reported case was a 47-year-old right-handed male afflicted with left parietal hemorrhage who exhibited finger agnosia and right-left disorientation for others and himself, acalculia accompanied by deficit of understanding numerical conceptions, and agraphia mainly in the form of disturbed reminiscence of kanji. Moreover, he was unable either to draw pictures of objects from visual memory or to describe their features verbally, though he could copy pictures and letters and recite long sentences (imitation). In addition, he complained that he was unable to use a Japanese dictionary because he could not recall the order of the Japanese syllabary. On subtests of standardized batteries, he was poor at picture completion, picture arrangement, block design and word similarities on the WAIS-R, and poor at paired associations on the WMS-R. These findings suggest the following. First, the patient is unable either to understand the order and correlation of objects in series, or to manipulate their arrangement mentally. Second, he cannot describe objects without visual stimuli. These traits include the four symptoms composing Gerstmann's syndrome, and they correspond to the process of arranging parts of an object into their proper configuration of mental imagery as described by Kosslyn (1988). We concluded that deficit of mental imagery manipulation is the “Grundstorung” of Gerstmann's syndrome.

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