Glaucoma is closely related to elevation of intraocular pressure （IOP）. Many studies have done on the effect of chronic elevation of lOP on the retina and optic nerve, but less attention was paid to the effect of ac...Glaucoma is closely related to elevation of intraocular pressure （IOP）. Many studies have done on the effect of chronic elevation of lOP on the retina and optic nerve, but less attention was paid to the effect of acute elevated lOP. Here we briefly review experimental studies on functional changes of the visual system from the retina to the visual cortex under acute elevated lOP condition, which is similar to that of acute primary angle-closure glaucoma.展开更多
A new no-reference blocking artifact metric for B-DCT compression video is presented in this paper. We first present a new definition of blocking artifact and a new method for measuring perceptive blocking artifact ba...A new no-reference blocking artifact metric for B-DCT compression video is presented in this paper. We first present a new definition of blocking artifact and a new method for measuring perceptive blocking artifact based on HVS taking into account the luminance masking and activity masking characteristic. Then, we propose a new concept of blocking artifact cluster and the algorithm for clustering blocking artifacts. Considering eye movement and fixation, we select several clusters with most serious blocking artifacts and utilize the average of their blocking artifacts to assess the total blocking artifact of B-DCT reconstructed video. Experimental results illustrating the performance of the proposed method are presented and evaluated.展开更多
We investigated, in young healthy participants, how the affective content of subliminally presented priming images and their specific visual attributes impacted conscious perception of facial expressions. The priming ...We investigated, in young healthy participants, how the affective content of subliminally presented priming images and their specific visual attributes impacted conscious perception of facial expressions. The priming images were broadly categorized as aggressive, pleasant, or neutral and further subcategorized by the presence of a face and by the centricity (egocentric or allocentric vantage-point) of the image content. Participants responded to the emotion portrayed in a pixelated target-face by indicating via key-press if the expression was angry or neutral. Response time to the neutral target face was significantly slower when preceded by face primes, compared to non-face primes (p < 0.05, Bonferroni corrected). In contrast, faster RTs were observed when angry target faces were preceded by face compared to non-face primes. In addition, participants’ performance was worse when a priming image contained an egocentric face compared to when it contained either an allocentric face or an egocentric non-face. The results suggest a significant impact of the visual features of the priming image on conscious perception of face expression.展开更多
The time until an approaching object passes the observer is referred to as time-to-passage (TTP). Accurate judgment of TTP is critical for visually guided navigation, such as when walking, riding a bicycle, or driving...The time until an approaching object passes the observer is referred to as time-to-passage (TTP). Accurate judgment of TTP is critical for visually guided navigation, such as when walking, riding a bicycle, or driving a car. Previous research has shown that observers are able to make TTP judgments in the absence of information about local retinal object expansion. In this paper we combine psychophysics and functional MRI (fMRI) to investigate the neural substrate of TTP processing. In a previous psychophysical study, we demonstrated that when local retinal expansion cues are not available, observers take advantage of multiple sources of information to judge TTP, such as optic flow and object retinal velocities, and integrate these cues through a flexible and economic strategy. To induce strategy changes, we introduced trials with motion but without coherent optic flow (0% coherence of the background), and trials with coherent, but noisy, optic flow (75% coherence of the background). In a functional magnetic resonance imaging (fMRI) study we found that coherent optic flow cues resulted in better behavioral performance as well as higher and broader cortical activations across the visual motion processing pathway. Blood oxygen-level-dependent (BOLD) signal changes showed significant involvement of optic flow processing in the precentral sulcus (PreCS), postcentral sulcus (PostCS) and middle temporal gyrus (MTG) across all conditions. Not only highly activated during motion processing, bilateral hMT areas also showed a complex pattern in TTP judgment processing, which reflected a flexible TTP response strategy.展开更多
Objective and Impact Statement.We propose an automated method of predicting Normal Pressure Hydrocephalus(NPH)from CT scans.A deep convolutional network segments regions of interest from the scans.These regions are th...Objective and Impact Statement.We propose an automated method of predicting Normal Pressure Hydrocephalus(NPH)from CT scans.A deep convolutional network segments regions of interest from the scans.These regions are then combined with MRI information to predict NPH.To our knowledge,this is the first method which automatically predicts NPH from CT scans and incorporates diffusion tractography information for prediction.Introduction.Due to their low cost and high versatility,CT scans are often used in NPH diagnosis.No well-defined and effective protocol currently exists for analysis of CT scans for NPH.Evans’index,an approximation of the ventricle to brain volume using one 2D image slice,has been proposed but is not robust.The proposed approach is an effective way to quantify regions of interest and offers a computational method for predicting NPH.Methods.We propose a novel method to predict NPH by combining regions of interest segmented from CT scans with connectome data to compute features which capture the impact of enlarged ventricles by excluding fiber tracts passing through these regions.The segmentation and network features are used to train a model for NPH prediction.Results.Our method outperforms the current state-of-the-art by 9 precision points and 29 recall points.Our segmentation model outperforms the current state-of-the-art in segmenting the ventricle,gray-white matter,and subarachnoid space in CT scans.Conclusion.Our experimental results demonstrate that fast and accurate volumetric segmentation of CT brain scans can help improve the NPH diagnosis process,and network properties can increase NPH prediction accuracy.展开更多
Precise and continuous monitoring of biochemicals by biosensors assists to understand physiological functions for various diagnostics and therapeutic applications.For implanted biosensors,small size and flexibility ar...Precise and continuous monitoring of biochemicals by biosensors assists to understand physiological functions for various diagnostics and therapeutic applications.For implanted biosensors,small size and flexibility are essential for minimizing tissue damage and achieving accurate detection.However,the active surface area of sensor decreases as the sensor becomes smaller,which will increase the impedance and decrease the signal to noise ratio,resulting in a poor detection limit.Taking advantages of local amplification effect,organic electrochemical transistors(OECTs)constitute promising candidates for high-sensitive monitoring.However,their detections in deep tissues are rarely reported.Herein,we report a family of implantable,fiber-shaped all-in-one OECTs based on carbon nanotube fibers for versatile biochemical detection including H2O2,glucose,dopamine and glutamate.These fiber-shaped OECTs demonstrated high sensitivity,dynamical stability in physiological environment and antiinterference capability.After implantation in mouse brain,7-day dopamine monitoring in vivo was realized for the first time.These fiber-shaped OECTs could be great additions to the"life science"tool box and represent promising avenue for biomedical monitoring.展开更多
The temporal properties of pattern adaptation of relay cells induced by repeated sinusoidal drifting grating were investigated in the dorsal lateral geniculate nucleus (dLGN) of cats. The results showed that the respo...The temporal properties of pattern adaptation of relay cells induced by repeated sinusoidal drifting grating were investigated in the dorsal lateral geniculate nucleus (dLGN) of cats. The results showed that the response amplitude declined and the response latency prolonged when relay cells were pattern-adapted in dLGN, like the similar findings in visual cortex. However, in contrast to the result in cortex, the response phase of relay cells advanced. This implies that an inhibition with relatively long latency may participate in the pattern adaptation of dLGN cells and the adaptation in dLGN may be via a mechanism different from that of visual cortex.展开更多
In this paper, a content based descriptor is pro- posed to retrieve 3D models, which employs histogram of local orientation （HLO） as a geometric property of the shape. The proposed 3D model descriptor scheme consist...In this paper, a content based descriptor is pro- posed to retrieve 3D models, which employs histogram of local orientation （HLO） as a geometric property of the shape. The proposed 3D model descriptor scheme consists of three steps. In the first step, Poisson equation is utilized to define a 3D model signature. Next, the local orientation is calculated for each voxel of the model using Hessian matrix. As the final step, a histogram-based 3D model descriptor is extracted by accumulating the values of the local orientation in bins. Due to efficiency of Poisson equation in describing the models with various structures, the proposed descriptor is capable of discriminating these models accurately. Since, the inner vox- els have a dominant contribution in the formation of the de- scriptor, sufficient robustness against noise can be achieved. This is because the noise mostly influences the boundary vox- els. Furthermore, we improve the retrieval performance us- ing support vector machine based one-shot score （SVM-OSS） similarity measure, which is more efficient than the conven- tional methods to compute the distance of feature vectors. The rotation normalization is performed employing the prin- cipal component analysis. To demonstrate the applicability of HLO, we implement experimental evaluations of precision- recall curve on ESB, PSB and WM-SHREC databases of 3D models. Experimental results validate the effectiveness of the proposed descriptor compared to some current methods.展开更多
Achieving real-time,continuous and long-term monitoring of dopamine(DA)in vivo is essential for revealing brain functions and preventing and treating neurogenic diseases.However,it remains challenging to achieve a low...Achieving real-time,continuous and long-term monitoring of dopamine(DA)in vivo is essential for revealing brain functions and preventing and treating neurogenic diseases.However,it remains challenging to achieve a low limit of detection(LOD)and high neuron-compatibility at the same time for the current microsensors,resulting in the failure of long-term and accurate detection of DA in vivo.A DA-sensing fiber was achieved by the potentiometric method to possess a low LOD of 5 nM,1-3 orders of magnitude lower than amperometry and differential-pulse voltammetry.The sensing fiber showed a wide linear range from 5 to 185 nM that well matched the DA concentration(26-40 nM)in vivo.After implantation,the sensing fiber showed no influence on the firing rates of neurons with the potentiometric test,indicating high neuron-compatibility.It was then integrated with electrophysiology to simultaneously monitor DA variation and electrical signal in the brain,with stable monitoring of DA change in vivo for 8 weeks.The sensing fiber was flexible and stably worked after hundreds of bending,and it showed high sensitivity even after protein adsorption,thus offering a reliable tool for neuroscience.展开更多
Among the visual cortex areas investigated, besides areas 17, 18 and 19, the lateral suprasylvian area (LS) is best studied. The cells in this area are mainly sensitive to the visual stimuli with the preferred moving ...Among the visual cortex areas investigated, besides areas 17, 18 and 19, the lateral suprasylvian area (LS) is best studied. The cells in this area are mainly sensitive to the visual stimuli with the preferred moving direction. The responses to stationary stimuli are poor and the cells have no orientation selectivity. Most cells show spatial summation and展开更多
Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells present...Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells presented direction sensitivity.This kind of directionsensitivity was also present in LGNd neurons of decorticate cats and dark-reared cats.Zhou et al.described two different types of direction sensitive cells in展开更多
Since Levick et al. found and studied the orientation biases of retinal ganglion cells of cats, there has been increasing interest in subcortical orientation sensitivity. Shou et al. studied the orientation sensitivit...Since Levick et al. found and studied the orientation biases of retinal ganglion cells of cats, there has been increasing interest in subcortical orientation sensitivity. Shou et al. studied the orientation sensitivity of dorsal geniculate nucleus (LGNd) relay cells of the cat in details. They found that cells with similar preferred orientation are clustered in the LGNd, which is apparent for all cell types (ON, OFF, X, Y) and cells with different receptive field locations in retina. It is suggested that the initial sorting of orientation functional columns in the visual cortex may begin in the LGNd.展开更多
Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area VI in the monkey still remains unclear. We quanti...Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area VI in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.展开更多
基金grants of the National Natural Science Foundation of China （No. 90208013, No. 30170249）.
文摘Glaucoma is closely related to elevation of intraocular pressure （IOP）. Many studies have done on the effect of chronic elevation of lOP on the retina and optic nerve, but less attention was paid to the effect of acute elevated lOP. Here we briefly review experimental studies on functional changes of the visual system from the retina to the visual cortex under acute elevated lOP condition, which is similar to that of acute primary angle-closure glaucoma.
基金Project (No. YJCB2003017MU) supported by Huawei Technology Fund, China
文摘A new no-reference blocking artifact metric for B-DCT compression video is presented in this paper. We first present a new definition of blocking artifact and a new method for measuring perceptive blocking artifact based on HVS taking into account the luminance masking and activity masking characteristic. Then, we propose a new concept of blocking artifact cluster and the algorithm for clustering blocking artifacts. Considering eye movement and fixation, we select several clusters with most serious blocking artifacts and utilize the average of their blocking artifacts to assess the total blocking artifact of B-DCT reconstructed video. Experimental results illustrating the performance of the proposed method are presented and evaluated.
文摘We investigated, in young healthy participants, how the affective content of subliminally presented priming images and their specific visual attributes impacted conscious perception of facial expressions. The priming images were broadly categorized as aggressive, pleasant, or neutral and further subcategorized by the presence of a face and by the centricity (egocentric or allocentric vantage-point) of the image content. Participants responded to the emotion portrayed in a pixelated target-face by indicating via key-press if the expression was angry or neutral. Response time to the neutral target face was significantly slower when preceded by face primes, compared to non-face primes (p < 0.05, Bonferroni corrected). In contrast, faster RTs were observed when angry target faces were preceded by face compared to non-face primes. In addition, participants’ performance was worse when a priming image contained an egocentric face compared to when it contained either an allocentric face or an egocentric non-face. The results suggest a significant impact of the visual features of the priming image on conscious perception of face expression.
文摘The time until an approaching object passes the observer is referred to as time-to-passage (TTP). Accurate judgment of TTP is critical for visually guided navigation, such as when walking, riding a bicycle, or driving a car. Previous research has shown that observers are able to make TTP judgments in the absence of information about local retinal object expansion. In this paper we combine psychophysics and functional MRI (fMRI) to investigate the neural substrate of TTP processing. In a previous psychophysical study, we demonstrated that when local retinal expansion cues are not available, observers take advantage of multiple sources of information to judge TTP, such as optic flow and object retinal velocities, and integrate these cues through a flexible and economic strategy. To induce strategy changes, we introduced trials with motion but without coherent optic flow (0% coherence of the background), and trials with coherent, but noisy, optic flow (75% coherence of the background). In a functional magnetic resonance imaging (fMRI) study we found that coherent optic flow cues resulted in better behavioral performance as well as higher and broader cortical activations across the visual motion processing pathway. Blood oxygen-level-dependent (BOLD) signal changes showed significant involvement of optic flow processing in the precentral sulcus (PreCS), postcentral sulcus (PostCS) and middle temporal gyrus (MTG) across all conditions. Not only highly activated during motion processing, bilateral hMT areas also showed a complex pattern in TTP judgment processing, which reflected a flexible TTP response strategy.
基金funded by the Alzheimer’s Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904)DOD ADNI (Department of Defense award number W81XWH-12-2-0012)+1 种基金supported by the following awards:National Institutes of Health (grant numbers T32-GM08620 and 5R01NS103774)National Science Foundation (grant number 1664172).
文摘Objective and Impact Statement.We propose an automated method of predicting Normal Pressure Hydrocephalus(NPH)from CT scans.A deep convolutional network segments regions of interest from the scans.These regions are then combined with MRI information to predict NPH.To our knowledge,this is the first method which automatically predicts NPH from CT scans and incorporates diffusion tractography information for prediction.Introduction.Due to their low cost and high versatility,CT scans are often used in NPH diagnosis.No well-defined and effective protocol currently exists for analysis of CT scans for NPH.Evans’index,an approximation of the ventricle to brain volume using one 2D image slice,has been proposed but is not robust.The proposed approach is an effective way to quantify regions of interest and offers a computational method for predicting NPH.Methods.We propose a novel method to predict NPH by combining regions of interest segmented from CT scans with connectome data to compute features which capture the impact of enlarged ventricles by excluding fiber tracts passing through these regions.The segmentation and network features are used to train a model for NPH prediction.Results.Our method outperforms the current state-of-the-art by 9 precision points and 29 recall points.Our segmentation model outperforms the current state-of-the-art in segmenting the ventricle,gray-white matter,and subarachnoid space in CT scans.Conclusion.Our experimental results demonstrate that fast and accurate volumetric segmentation of CT brain scans can help improve the NPH diagnosis process,and network properties can increase NPH prediction accuracy.
基金the National Natural Science Foundation of China(2163400351673043)+3 种基金Ministry of Science and Technology of China(2016YFA0203302)Science and Technology Commission of Shanghai Municipality(17QA1400400)Shanghai Municipal Education Commission(2017-01-07-00-07-E00062)Yanchang Petroleum Group。
文摘Precise and continuous monitoring of biochemicals by biosensors assists to understand physiological functions for various diagnostics and therapeutic applications.For implanted biosensors,small size and flexibility are essential for minimizing tissue damage and achieving accurate detection.However,the active surface area of sensor decreases as the sensor becomes smaller,which will increase the impedance and decrease the signal to noise ratio,resulting in a poor detection limit.Taking advantages of local amplification effect,organic electrochemical transistors(OECTs)constitute promising candidates for high-sensitive monitoring.However,their detections in deep tissues are rarely reported.Herein,we report a family of implantable,fiber-shaped all-in-one OECTs based on carbon nanotube fibers for versatile biochemical detection including H2O2,glucose,dopamine and glutamate.These fiber-shaped OECTs demonstrated high sensitivity,dynamical stability in physiological environment and antiinterference capability.After implantation in mouse brain,7-day dopamine monitoring in vivo was realized for the first time.These fiber-shaped OECTs could be great additions to the"life science"tool box and represent promising avenue for biomedical monitoring.
基金the National NaturalScience Foundation of China (Grant Nos. 97908003 and 30070257) the Foundation of the Chinese Academy of Sciences (Grant No. 39893340-03).
文摘The temporal properties of pattern adaptation of relay cells induced by repeated sinusoidal drifting grating were investigated in the dorsal lateral geniculate nucleus (dLGN) of cats. The results showed that the response amplitude declined and the response latency prolonged when relay cells were pattern-adapted in dLGN, like the similar findings in visual cortex. However, in contrast to the result in cortex, the response phase of relay cells advanced. This implies that an inhibition with relatively long latency may participate in the pattern adaptation of dLGN cells and the adaptation in dLGN may be via a mechanism different from that of visual cortex.
文摘In this paper, a content based descriptor is pro- posed to retrieve 3D models, which employs histogram of local orientation （HLO） as a geometric property of the shape. The proposed 3D model descriptor scheme consists of three steps. In the first step, Poisson equation is utilized to define a 3D model signature. Next, the local orientation is calculated for each voxel of the model using Hessian matrix. As the final step, a histogram-based 3D model descriptor is extracted by accumulating the values of the local orientation in bins. Due to efficiency of Poisson equation in describing the models with various structures, the proposed descriptor is capable of discriminating these models accurately. Since, the inner vox- els have a dominant contribution in the formation of the de- scriptor, sufficient robustness against noise can be achieved. This is because the noise mostly influences the boundary vox- els. Furthermore, we improve the retrieval performance us- ing support vector machine based one-shot score （SVM-OSS） similarity measure, which is more efficient than the conven- tional methods to compute the distance of feature vectors. The rotation normalization is performed employing the prin- cipal component analysis. To demonstrate the applicability of HLO, we implement experimental evaluations of precision- recall curve on ESB, PSB and WM-SHREC databases of 3D models. Experimental results validate the effectiveness of the proposed descriptor compared to some current methods.
基金the National Natural Science Foundation of China(22075050,21634003)the Ministry of Science and Technology of China(2016YFA0203302)+1 种基金the Science and Technology Commission of Shanghai Municipality(20JC1414902)Shanghai Municipal Education Commission(2017-01-07-00-07-E00062)。
文摘Achieving real-time,continuous and long-term monitoring of dopamine(DA)in vivo is essential for revealing brain functions and preventing and treating neurogenic diseases.However,it remains challenging to achieve a low limit of detection(LOD)and high neuron-compatibility at the same time for the current microsensors,resulting in the failure of long-term and accurate detection of DA in vivo.A DA-sensing fiber was achieved by the potentiometric method to possess a low LOD of 5 nM,1-3 orders of magnitude lower than amperometry and differential-pulse voltammetry.The sensing fiber showed a wide linear range from 5 to 185 nM that well matched the DA concentration(26-40 nM)in vivo.After implantation,the sensing fiber showed no influence on the firing rates of neurons with the potentiometric test,indicating high neuron-compatibility.It was then integrated with electrophysiology to simultaneously monitor DA variation and electrical signal in the brain,with stable monitoring of DA change in vivo for 8 weeks.The sensing fiber was flexible and stably worked after hundreds of bending,and it showed high sensitivity even after protein adsorption,thus offering a reliable tool for neuroscience.
基金Project supported by the National Natural Science Foundation of China, and the Vision Information Processing Laboratory, Institute of Biophysics, Academia Sinica, Beijing.
文摘Among the visual cortex areas investigated, besides areas 17, 18 and 19, the lateral suprasylvian area (LS) is best studied. The cells in this area are mainly sensitive to the visual stimuli with the preferred moving direction. The responses to stationary stimuli are poor and the cells have no orientation selectivity. Most cells show spatial summation and
基金supported by the National Natural Science Foundation of China, Chinese Academy of Sciences (CAS)the State. Science and Technology Commission of ChinaLaboratory for Visual Information Processing, Institute of Biophysics, CAS.
文摘Direction sensitivity is an important receptive property of visual cortical cells.On thesubcortical visual pathways,recent studies have shown that about 32% of LGNd relay cellsand 25% of retinal ganglion cells presented direction sensitivity.This kind of directionsensitivity was also present in LGNd neurons of decorticate cats and dark-reared cats.Zhou et al.described two different types of direction sensitive cells in
基金Project supported by the National Natural Science Foundation of China, Academia Sinica, the National Science and Technology Commission of China, Huo Ying-Dong Foundation for Young Teachers and the Award for Young Teachers of the National Education Commis
文摘Since Levick et al. found and studied the orientation biases of retinal ganglion cells of cats, there has been increasing interest in subcortical orientation sensitivity. Shou et al. studied the orientation sensitivity of dorsal geniculate nucleus (LGNd) relay cells of the cat in details. They found that cells with similar preferred orientation are clustered in the LGNd, which is apparent for all cell types (ON, OFF, X, Y) and cells with different receptive field locations in retina. It is suggested that the initial sorting of orientation functional columns in the visual cortex may begin in the LGNd.
文摘Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area VI in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.
