• 双眼的神经机制与知觉学习效应

    分类: 心理学 >> 认知心理学 提交时间: 2020-08-15

    摘要: 双眼瞳距使得空间某物体在左右眼视网膜的成像存在微小位置差异,这种差异被称为双眼视差(binocular disparity),是立体视知觉的重要信息来源。对双眼视差的心理物理学研究始于十八世纪初,迄今已有接近两百年的历史。近年来,双眼视差研究主要集中在两方面。其一是用电生理、脑成像技术考察双眼视差在视觉背、腹侧通路的模块化表征,其脑区表征反映出视觉系统的层级式、平行式加工规律。其二是应用知觉学习范式研究双眼视差的可塑性。未来研究应综合脑成像和神经调控技术考察双眼视差的神经机制及其学习效应,包括双眼视差与多种深度线索间的信息整合和交互作用。应用方向上,可结合虚拟现实等技术优化训练范式,实现立体视力的康复和增强。

  • 利用测地观测中搭载式相位参考模式观测射电星Del Lib和HR 1099

    分类: 天文学 >> 天文学 提交时间: 2023-11-24 合作期刊: 《天文研究与技术》

    摘要: 基于盖亚( Gaia) 天体测量数据建立的盖亚天体参考系( Gaia Celestial Reference Frame,GCRF)与基于甚长基线干涉测量(Very Long Baseline Interferometry,VLBI)建立的国际天球参考系(International Celestial Reference Frame,ICRF)具有一定的系统差异,需要对盖亚的数据进行外部的独立评估,以建立光学和射电参考架连接。国际上对参考架的连接普遍采用在光学和射电波段都有辐射的天体,在暗端(星等G15)使用类星体,在亮端( G13) 使用射电星。由于普通VLBI 观测申请批准的周期长,难度大,因此,我们尝试将一部分射电星的观测转向数量较多的测地观测,在测地观测中搭载相位参考模式来观测射电星。为了测试这种观测的可行性,我们在IVS(The International VLBI Service for Geodesy and Astrometry)和LBA(Large Baseline Array)的测地观测中搭载相位参考观测,选取Del Lib和HR 1099 作为实验的目标源。观测得到了这两颗射电星的VLBI图像、流量和单历元坐标,且坐标精度高于前人;同时结合前人的数据,对这两颗射电星进行了视差和自行拟合,结果与前人和盖亚的结果相符,且部分精度更高。验证了测地模式中搭载相位参考观测射电星的可行性, 为后续丰富射电星VLBI 天体测量样本,连接光学与射电参考架奠定了一定的基础。

  • 基于自适应权重的遮挡信息立体匹配算法

    分类: 计算机科学 >> 计算机科学的集成理论 提交时间: 2019-01-03 合作期刊: 《计算机应用研究》

    摘要: 针对传统局部立体匹配算法在深度不连续区域误匹配率高的问题,提出一种基于自适应权重的遮挡信息立体匹配算法。首先,采用左右一致性检测算法检测参考图像与目标图像的遮挡区域;然后利用遮挡信息,在代价聚合阶段降低遮挡区域像素点所占权重,在视差优化阶段采用扫描线传播方式选择水平方向最近点填充遮挡区域的视差;最后,根据Middlebury数据集提供的标准视差图为视差结果计算误匹配率。实验结果表明,基于自适应权重的遮挡信息匹配算法相对于自适应权重算法误匹配率降低了16%,并解决了局部立体匹配算法在深度不连续区域误匹配率高的问题,提高了算法的匹配精确性。

  • The effect of perceptual learning on the sensitivity and stability of double fusion in Panum’s Limiting Case

    分类: 心理学 >> 实验心理学 提交时间: 2021-03-08

    摘要: Panum’s limiting case is a typical phenomenon of monocular occlusion in binocular vision. It occurs naturally when one object is occluded by another object for one eye, but in the other eye the two objects are located in different directions. Only recently has it been found that in addition to horizontal disparity, the vertical disparity gradient and cue conflict are two important determinants for double fusion. Therefore, the current study aims to determine the relationship between the two determinants and perceptual learning in Panum’s limiting case. Twenty-six observers were trained for five days. Meanwhile, the RTs and duration of double fusion was measured when the participants viewed several versions of Panum’s configuration. In these stimuli, vertical disparity gradient was varied from 0.1 to 0.6 and cue conflict was manipulated from low to high. The results revealed that for each level of these factors, the RTs of double fusion decreased and the duration of double fusion increased with each training session. Moreover, there were significant differences among different levels of vertical disparity gradient and cue conflict. Lastly, there was also a significant interaction effect between the two determinants in Panum’s limiting case. These results suggest that there is perceptual learning for each level of the two determinants in monocular occlusion and these factors jointly affect the sensitivity and stability of double fusion.