The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics ...The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.展开更多
It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this s...It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.展开更多
Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, how...Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.展开更多
A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based...A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based model developed by self-programming can meet current requirements of most local authorities,especially in developing countries.In this model,two cases,non-source flood and source flood,are distinguished and the Seed-spread algorithm suitable for source-flood is discussed;The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data.and all thematic maps are converted to raster format before overlay analysis.Two measures are taken to improve the operation efficiency of speed seed-spread algorithm.The accuracy of the model mainly depends on the resolution and precision of the DEM data,and the accuracy of registering all raster layers and the quality of attribute data.展开更多
在中国正进一步推进以国家公园为主体的自然保护地体系建设的背景下,自然保护地社区发展研究日渐受到学界重视。运用CiteSpace软件,对2003—2023年中国知网(CNKI)数据库与Web of Science核心合集数据库中关于自然保护地社区发展研究的...在中国正进一步推进以国家公园为主体的自然保护地体系建设的背景下,自然保护地社区发展研究日渐受到学界重视。运用CiteSpace软件,对2003—2023年中国知网(CNKI)数据库与Web of Science核心合集数据库中关于自然保护地社区发展研究的相关文献进行可视化分析。研究发现:(1)2003—2023年间该领域研究总体呈增长趋势,具体可划分为“研究起步”、“研究发展”及“研究深化”3个阶段;(2)国外大部分研究机构间已形成紧密的合作网络,国内仅少部分研究机构间形成了紧密的合作网络,其余机构间合作有待深入;(3)国内外研究热点内容各有侧重但亦有相似之处。最后,提出未来的研究热点将集中于自然保护地社区参与生态旅游相关研究、自然保护地治理机制体制研究及自然保护地社区协同发展研究3个方面。展开更多
基金supported by travel grants from Monash University and the University of Sichuan(to YY)Research Grants from the Australian Research Council(No.DP0451206)(to MGPR)National Health and Medical Research Council(No.384115)(to MGPR)。
文摘The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.
文摘It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.
基金National Natural Science Foundation of China (31171082)Natural Science Foundation of Anhui Province (070413138)Key Research Foundation of Anhui Province Education Department (KJ2009A167)
文摘Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.
文摘A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based model developed by self-programming can meet current requirements of most local authorities,especially in developing countries.In this model,two cases,non-source flood and source flood,are distinguished and the Seed-spread algorithm suitable for source-flood is discussed;The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data.and all thematic maps are converted to raster format before overlay analysis.Two measures are taken to improve the operation efficiency of speed seed-spread algorithm.The accuracy of the model mainly depends on the resolution and precision of the DEM data,and the accuracy of registering all raster layers and the quality of attribute data.
文摘在中国正进一步推进以国家公园为主体的自然保护地体系建设的背景下,自然保护地社区发展研究日渐受到学界重视。运用CiteSpace软件,对2003—2023年中国知网(CNKI)数据库与Web of Science核心合集数据库中关于自然保护地社区发展研究的相关文献进行可视化分析。研究发现:(1)2003—2023年间该领域研究总体呈增长趋势,具体可划分为“研究起步”、“研究发展”及“研究深化”3个阶段;(2)国外大部分研究机构间已形成紧密的合作网络,国内仅少部分研究机构间形成了紧密的合作网络,其余机构间合作有待深入;(3)国内外研究热点内容各有侧重但亦有相似之处。最后,提出未来的研究热点将集中于自然保护地社区参与生态旅游相关研究、自然保护地治理机制体制研究及自然保护地社区协同发展研究3个方面。
