Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual a...Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual acuity testing. Moreover, in 3 out of the 4, the process of reading a text appeared cognitively impaired. Methods: As a supplement to conventional visual field testing, the present analysis focus was on microperimetry by Scanning Laser Ophthalmocopy (SLO). Our aim was to identify the perceptual retinal counterparts to the temporally located visual field defects as caused by the visual pathway lesion on a chiasmal level, possibly also to indicate the apparently ineffective saccadic movements underlying that only part of the line on the chart could be given. Results and Conclusions: The central retinal areas with lacking recognition by SLO testing were given by black rectangles expressing scotomatous points;they clustered in a zone extending nasally from the fixation area, as expected. The methodology further depicted an orderly fixation in two cases, and only minor deviation in two. Fixation saccades thus were considered by and large within normal and with only exceptional outlier points recorded. All considered, the shortcomings of the perceptual mechanisms underlying the lateralised visual inattention as observed in the four patients have remained without a satisfactory explanation.展开更多
Objective:To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat,and visual development plastic stage and visual plasticity in adult rats.Methods:A ...Objective:To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat,and visual development plastic stage and visual plasticity in adult rats.Methods:A total of 60 SD rats ages 13 d were randomly divided into A,B,C three groups with 20 in each group,group A was set as the normal control group without any processing,group B was strabismus amblyopic group,using the unilateral extraocular rectus resection to establish the strabismus amblyopia model,group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection+lid suture.At visual developmental early phase(P2S),meta phase(P3S),late phase(P45)and adult phase(P120),the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry.Neuron morphological changes in lateral geniculate body and visual cortex was observed,the positive neurons differences of C-fos expression induced by light stimulation was measured in each group,and the condition of radiation development of P120 amblyopic adult rats was observed.Results:In groups B and C,C-fos positive cells were significantly lower than the control group at P25(P<0.05),there was no statistical difference of C-fos protein positive cells between group B and group A(P>0.05),C-fos protein positive cells level of group B was significantly lower than that of group A(P<0.05).The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35,P4S and P120 with statistically significant differences(P<0.05).Conclusions:The increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.展开更多
Purpose/Aim: We aimed to investigate the effect of monocular blur on the binocular visual field. Materials and Methods: A total of 13 healthy young volunteers participated in this study. The mean subjective refractive...Purpose/Aim: We aimed to investigate the effect of monocular blur on the binocular visual field. Materials and Methods: A total of 13 healthy young volunteers participated in this study. The mean subjective refractive error of the dominant eye (DE) was -3.33 ± 1.65D, and the non-dominant eye (NDE) was -3.15 ± 2.84D. The DE was determined by using the hole-in-the-card test. The visual field was examined by the Humphrey Visual Field Analyzer using the 30-2 SITA Standard program. The visual field was measured while wearing soft contact lens under three conditions;① both eyes: near vision correction;② DE: near vision correction +3.00D added, NDE: near vision correction;and ③ DE: near vision correction, NDE: near vision correction +3.00D added. The foveal threshold, mean deviation (MD), and pattern standard deviation (PSD) values were investigated. Results: The foveal threshold value (dB) at ①, ②, and ③ was 41.2, 37.8, and 38.1, respectively. The values at ② and ③ were both significantly lower than that at ① (p Conclusion: These results suggest that monocular blur reduced the sensitivity within the binocular visual field.展开更多
Background Based on the seminal work proposed by Zhou et al., much of the recent progress in learning monocular visual odometry, i.e., depth and camera motion from monocular videos, can be attributed to the tricks in ...Background Based on the seminal work proposed by Zhou et al., much of the recent progress in learning monocular visual odometry, i.e., depth and camera motion from monocular videos, can be attributed to the tricks in the training procedure, such as data augmentation and learning objectives. Methods Herein, we categorize a collection of such tricks through the theoretical examination and empirical evaluation of their effects on the final accuracy of the visual odometry. Results/Conclusions By combining the aforementioned tricks, we were able to significantly improve a baseline model adapted from SfMLearner without additional inference costs. Furthermore, we analyzed the principles of these tricks and the reason for their success. Practical guidelines for future research are also presented.展开更多
目的探讨经颅直流电刺激(transcranial direct current stimulation,tDCS)对单眼剥夺(Monocular deprivation,MD)大鼠初级视皮层(V1)中CAMKⅡ、CREB和SYN1蛋白表达及视觉能力的影响,为弱视治疗提供理论基础。方法55只SPF级新生SD大鼠,...目的探讨经颅直流电刺激(transcranial direct current stimulation,tDCS)对单眼剥夺(Monocular deprivation,MD)大鼠初级视皮层(V1)中CAMKⅡ、CREB和SYN1蛋白表达及视觉能力的影响,为弱视治疗提供理论基础。方法55只SPF级新生SD大鼠,从中选取43只于出生后14 d缝合右侧上下眼睑以建立单眼剥夺模型,单眼剥夺2周后选取36只缝合严密不漏光的大鼠随机分为模型组(MD)、阳极治疗组(anodaltDCS,a-tDCS)、假治疗组(shamtDCS,s-tDCS)。模型建立后进行为期14 d的tDCS治疗,对a-tDCS组每天施以1mA直流电刺激,每天1次,每次20 min;s-tDCS组只在刺激开始后1 min和结束前1 min给予电流刺激。视觉水迷宫用于测试视觉辨别能力和选择行为。图形视觉诱发电位(Pattern visual evoked potential,P-VEP)检测各组大鼠P100波振幅和潜伏期;HE染色观察V1中细胞形态和排列情况;Westernblot法检测V1中CaMKⅡ、CREB和SYN1蛋白表达水平;免疫组织化学染色观察SYN1阳性细胞数量。结果与Control组比较,MD组大鼠视觉辨别能力降低,选择正确率显著下降(P<0.0001);P100波振幅显著降低(P<0.001),潜伏期延长(P<0.001);V1中核仁皱缩,细胞排列不规整;CaMKⅡ、CREB和SYN1蛋白表达量下降(P<0.001);SYN1蛋白的平均阳性细胞数量减少(P<0.0001)。a-tDCS组与MD组相比,大鼠视觉辨别能力显著改善,选择正确率升高(P<0.0001);P100波振幅升高(P<0.001),潜伏期缩短(P<0.001);V1神经元排列规整,皱缩有所减少;CaMKⅡ、CREB和SYN1蛋白表达量显著升高(P<0.001);V1中SYN1蛋白的平均阳性细胞数量增加(P<0.05)。s-tDCS对MD组无治疗作用。结论a-tDCS可改善单眼剥夺大鼠的视觉能力,其机制可能与a-tDCS通过CaMKⅡ/CREB通路调节V1神经元突触可塑性有关。展开更多
文摘Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual acuity testing. Moreover, in 3 out of the 4, the process of reading a text appeared cognitively impaired. Methods: As a supplement to conventional visual field testing, the present analysis focus was on microperimetry by Scanning Laser Ophthalmocopy (SLO). Our aim was to identify the perceptual retinal counterparts to the temporally located visual field defects as caused by the visual pathway lesion on a chiasmal level, possibly also to indicate the apparently ineffective saccadic movements underlying that only part of the line on the chart could be given. Results and Conclusions: The central retinal areas with lacking recognition by SLO testing were given by black rectangles expressing scotomatous points;they clustered in a zone extending nasally from the fixation area, as expected. The methodology further depicted an orderly fixation in two cases, and only minor deviation in two. Fixation saccades thus were considered by and large within normal and with only exceptional outlier points recorded. All considered, the shortcomings of the perceptual mechanisms underlying the lateralised visual inattention as observed in the four patients have remained without a satisfactory explanation.
文摘Objective:To explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat,and visual development plastic stage and visual plasticity in adult rats.Methods:A total of 60 SD rats ages 13 d were randomly divided into A,B,C three groups with 20 in each group,group A was set as the normal control group without any processing,group B was strabismus amblyopic group,using the unilateral extraocular rectus resection to establish the strabismus amblyopia model,group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection+lid suture.At visual developmental early phase(P2S),meta phase(P3S),late phase(P45)and adult phase(P120),the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry.Neuron morphological changes in lateral geniculate body and visual cortex was observed,the positive neurons differences of C-fos expression induced by light stimulation was measured in each group,and the condition of radiation development of P120 amblyopic adult rats was observed.Results:In groups B and C,C-fos positive cells were significantly lower than the control group at P25(P<0.05),there was no statistical difference of C-fos protein positive cells between group B and group A(P>0.05),C-fos protein positive cells level of group B was significantly lower than that of group A(P<0.05).The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35,P4S and P120 with statistically significant differences(P<0.05).Conclusions:The increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.
文摘Purpose/Aim: We aimed to investigate the effect of monocular blur on the binocular visual field. Materials and Methods: A total of 13 healthy young volunteers participated in this study. The mean subjective refractive error of the dominant eye (DE) was -3.33 ± 1.65D, and the non-dominant eye (NDE) was -3.15 ± 2.84D. The DE was determined by using the hole-in-the-card test. The visual field was examined by the Humphrey Visual Field Analyzer using the 30-2 SITA Standard program. The visual field was measured while wearing soft contact lens under three conditions;① both eyes: near vision correction;② DE: near vision correction +3.00D added, NDE: near vision correction;and ③ DE: near vision correction, NDE: near vision correction +3.00D added. The foveal threshold, mean deviation (MD), and pattern standard deviation (PSD) values were investigated. Results: The foveal threshold value (dB) at ①, ②, and ③ was 41.2, 37.8, and 38.1, respectively. The values at ② and ③ were both significantly lower than that at ① (p Conclusion: These results suggest that monocular blur reduced the sensitivity within the binocular visual field.
文摘为提高6轴机器人的运动学绝对定位精度,提出了一种闭环校准方法.首先,通过视觉位姿测量方法,建立多点位姿约束;其次,利用差分方法构建辨识方程;最后,采用加权最小二乘法对机器人运动学参数进行辨识.测量设备为安装在机器人末端的相机,其与固定的高精度标定板配合使用,以实现多点位姿约束.根据工业应用中的逆解参数约束条件和手眼系统的运动学耦合关系,确定了包含14个参数的最小校准参数集.基于此参数集,应用加权最小二乘法进行参数辨识,从而完成了机器人的运动学参数校准.采用该方法对华数HSR-JR605机器人进行校准后,机器人末端绕点运动的平均距离误差显著降低,从2.77 mm降低到0.42 mm.
文摘Background Based on the seminal work proposed by Zhou et al., much of the recent progress in learning monocular visual odometry, i.e., depth and camera motion from monocular videos, can be attributed to the tricks in the training procedure, such as data augmentation and learning objectives. Methods Herein, we categorize a collection of such tricks through the theoretical examination and empirical evaluation of their effects on the final accuracy of the visual odometry. Results/Conclusions By combining the aforementioned tricks, we were able to significantly improve a baseline model adapted from SfMLearner without additional inference costs. Furthermore, we analyzed the principles of these tricks and the reason for their success. Practical guidelines for future research are also presented.
