The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation, but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown....The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation, but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown. Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes, and thus may carry accurate stimulus-related information. Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus. The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency (bursts/s) and burst length (spikes/burst), but increased burst duration and the interspike interval within bursts. These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections, which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.展开更多
The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation,but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown.C...The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation,but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown.Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes,and thus may carry accurate stimulus-related information.Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus.The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency(bursts/s)and burst length(spikes/burst),but increased burst duration and the interspike interval within bursts.These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections,which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.展开更多
Adaptive rendering large and complex spatial data has become an important research issue in a 3DGIS application. In order to transmit the data to the client efficiently, this paper proposes a node-layer data model to ...Adaptive rendering large and complex spatial data has become an important research issue in a 3DGIS application. In order to transmit the data to the client efficiently, this paper proposes a node-layer data model to manage the 3D scene. Because the large spatial data and limited network bandwidth are the main bottlenecks of web-based 3DGIS, a client/server architecture including progressive transmission methods and multiresolution representations, together with the spatial index, are developed to improve the performance. All this makes the application quite scalable. Experimental results reveal that the application works appropriately.展开更多
3D city models,which are important items of content on the virtual globe,are characterized by complicated structures and large amounts of data.These factors make the visualization of 3D city models highly dependent up...3D city models,which are important items of content on the virtual globe,are characterized by complicated structures and large amounts of data.These factors make the visualization of 3D city models highly dependent upon the performance of computer hardware.Thus,achieving the efficient rendering of 3D city models using different hardware performance levels represents one of the key problems currently facing researchers.This paper proposes a time-critical adaptive visualization method that first estimates the possible rendering time for each model according to the data structure of the model in addition to the CPU/GPU performance of the computer.It then dynamically adjusts the rendering level for each model based on the results of an estimation of the rendering time to ensure that the final scene can be completed within a given time.To verify the effectiveness and flexibility of this method,it is applied using different computers.The results show that the adaptive visualization method presented in this paper not only can adapt to computers with different levels of performances but also demonstrates an obvious improvement in the time estimation precision,visual effects,and optimization speed relative to existing adaptive visualization methods.展开更多
An objective visual performance evaluation with visual evoked potential (VEP) measurements was first inte- grated into an adaptive optics (AO) system. The optical and neural limits to vision can be bypassed throug...An objective visual performance evaluation with visual evoked potential (VEP) measurements was first inte- grated into an adaptive optics (AO) system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.展开更多
基金supported by the National Natural Science Foundation of China (31171082)the Natural Science Foundation of Anhui Province (070413138)+1 种基金the Key Research Foundation of the Anhui Provincial Education Department (KJ2009A167)the Foundation of Key Laboratories of Anhui Province and the Anhui Provincial Education Department
文摘The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation, but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown. Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes, and thus may carry accurate stimulus-related information. Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus. The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency (bursts/s) and burst length (spikes/burst), but increased burst duration and the interspike interval within bursts. These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections, which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.
基金This work was supported by the National Natural Science Foundation of China(31171082)the Natural Science Foundation of Anhui Province(070413138)+1 种基金the Key Research Foundation of the Anhui Provincial Education Department(KJ2009A167)the Foundation of Key Laboratories of Anhui Province and the Anhui Provincial Education Department.
文摘The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation,but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown.Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes,and thus may carry accurate stimulus-related information.Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus.The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency(bursts/s)and burst length(spikes/burst),but increased burst duration and the interspike interval within bursts.These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections,which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.
基金the National High-Tech Research & Development Program of China (Grant Nos. 2006AA12Z220, 2006AA12Z114)the National Basic Research Program of China (Grant No. 2007CB714403)the National Natural Science Foundation of China (Grant No. 60502008)
文摘Adaptive rendering large and complex spatial data has become an important research issue in a 3DGIS application. In order to transmit the data to the client efficiently, this paper proposes a node-layer data model to manage the 3D scene. Because the large spatial data and limited network bandwidth are the main bottlenecks of web-based 3DGIS, a client/server architecture including progressive transmission methods and multiresolution representations, together with the spatial index, are developed to improve the performance. All this makes the application quite scalable. Experimental results reveal that the application works appropriately.
基金the National Key R&D Program of China[grant number 2017YFB0503703]The Nature Science Foundation Innovation Group Project of Hubei Province,China[grant number 2016CFA003]The LIESMARS Special Research Funding。
文摘3D city models,which are important items of content on the virtual globe,are characterized by complicated structures and large amounts of data.These factors make the visualization of 3D city models highly dependent upon the performance of computer hardware.Thus,achieving the efficient rendering of 3D city models using different hardware performance levels represents one of the key problems currently facing researchers.This paper proposes a time-critical adaptive visualization method that first estimates the possible rendering time for each model according to the data structure of the model in addition to the CPU/GPU performance of the computer.It then dynamically adjusts the rendering level for each model based on the results of an estimation of the rendering time to ensure that the final scene can be completed within a given time.To verify the effectiveness and flexibility of this method,it is applied using different computers.The results show that the adaptive visualization method presented in this paper not only can adapt to computers with different levels of performances but also demonstrates an obvious improvement in the time estimation precision,visual effects,and optimization speed relative to existing adaptive visualization methods.
基金supported by the National Natural Science Foundation of China (No. 61378064)the National High Technology Research and Development Program of China (No. 2015AA020510)
文摘An objective visual performance evaluation with visual evoked potential (VEP) measurements was first inte- grated into an adaptive optics (AO) system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.