Attribute Pair-Based Visual Recognition and Memory

Background: In the human visual system, different attributes of an object, such as shape, color, and motion, are processed separately in different areas of the brain. This raises a fundamental question of how are these attributes integrated to produce a unified perception and a specific response. This ‘‘binding problem’ ’ is computationally difficult because all attributes are assumed to be bound together to form a single object representation. However, there is no firm evidence to confirm that such representations exist for general objects. Methodology/Principal Findings: Here we propose a paired-attribute model in which cognitive processes are based on multiple representations of paired attributes. In line with the model’s prediction, we found that multiattribute stimuli can produce an illusory perception of a multiattribute object arising from erroneous integration of attribute pairs, implying that object recognition is based on parallel perception of paired attributes. Moreover, in a change-detection task, a feature change in a single attribute frequently caused an illusory perception of change in another attribute, suggesting that multiple pairs of attributes are stored in memory. Conclusions/Significance: The paired-attribute model can account for some novel illusions and controversial findings on binocular rivalry and short-term memory. Our results suggest that many cognitive processes are performed at the level of paired attributes rather than integrated objects, which greatly facilitates the binding problem and provides simple

Changes of Lysosomes in Autolysis. Histochemical, Biochemical and Electron Microscopic Studies in the Early Stage of Autolysis.

1.Changes of lysosomes of rat hepatic cells in the process of autolysis were investigated histochemically, biochemibally and electron microscopically on the aseptically incubated liver tissues. 2. Lysosomes identified by histochemical examinations of AcPase activity were seen as discrete granules along the bile canalicli of the hepatic cell plates. After 3 hrs. of the incubation, the granules in the hepatic cells surrounding the central vein showed poorly defined contour with decreased density, and the enzymatic activity was not confined to the granules but appeared to disperse into the cytoplasm. With the time of incubation, these changes became distinct and gradually extended to peripheral area of the lobules. 3. Biochemically the AcPase activity in the supernatant fraction and also the activity available in the homogenate showed the gradual increase in the process of incubation. The addition of ATP to the isolated lysosomes protected the membrane against the release of the enzymes concerned. 4. Electron microscopically, among the various morphological changes of the cytoplasmic organelles observed, characteristic changes of the cytoplasmic membranes on the sinusoidal border and those of bile canaliculi and certain alterations of mitochondria were conspicuously noted prior to the ultrastructural alterations of lysosomes. It is concluded that the changes in cytoplasmic membranes of the hepatic cells in the early stages of autolysis precede the release of lysosomal hydrolases, whereas the ATP-level is lowered, the releasing of lysosomal enzymes is accelerated and leads to the lytic changes of the cytoplasm in the later stages

Lysosomal and Some Other Hydrolytic Enzyme Activities in The Whole Liver and Isolated Hepatocyte Suspension.

Enzyme activities were studied with the liver tissue and isolated hepatocyte homogenates. The activities of alkaline phosphatase, 5'-nucleotidase, adenosine triphosphatase, glucose-6-phosphatase, and various lysosomal enzymes were different between the hepatocytes and non-hepatocyte components in rat liver. The significance of the isolation of hepatocytes from the liver tissue is discussed.departmental bulletin pape

An Autopsy Case of a Cavernous Hemangioma with Solitary Fibromatous Fibrosis within the Cavernous Space in the Liver of an Adult.

An autopsy case of a cavernous hemangioma in the liver found accidentally in an adult was reported. It is not so rare to find the small sized hemangioma but unusual to discover a tumorlike fibrous nodule in a solitary state in the central part of the hemangioma. The origin and formation of the fibrous nodule were discussed.departmental bulletin pape

Visual Feature Integration of Three Attributes in Stimulus-Response Mapping Is Distinct From That of Two

In the human visual system, different attributes of an object are processed separately and are thought to be then temporarily bound by attention into an integrated representation to produce a specific response. However, if such representations existed in the brain for arbitrary multi-attribute objects, a combinatorial explosion problem would be unavoidable. Here, we show that attention may bind features of different attributes only in pairs and that bound feature pairs, rather than integrated object representations, are associated with responses for unfamiliar objects. We found that in a mapping task from three-attribute stimuli to responses, presenting three attributes in pairs (two attributes in each window) did not significantly complicate feature integration and response selection when the stimuli were not very familiar. We also found that repeated presentation of the same triple conjunctions significantly improved performance on the stimulus-response task when the correct responses were determined by the combination of three attributes, but this familiarity effect was not observed when the response could be determined by two attributes. These findings indicate that integration of three or more attributes is a distinct process from that of two, requiring long-term learning or some serial process. This suggests that integrated object representations are not formed or are formed only for a limited number of very familiar objects, which resolves the computational difficulty of the binding problem

基礎および臨床的側面からみたアミノ酸投与が血管内皮機能および動脈壁硬化に及ぼす生理的影響に関する研究

学位の種別: 論文博士審査委員会委員 : （主査）東京大学教授 佐藤 隆一郎, 東京大学特任教授 加藤 久典, 東京大学准教授 戸塚 護, 東京大学准教授 三坂 巧, 東京大学准教授 井上 順University of Tokyo(東京大学

対属性仮説に基づく結合問題の解決と多次元情報統合過程のモデル化

科学研究費助成事業 研究成果報告書：挑戦的萌芽研究2014-2017課題番号 : 2659017