大学生运动知觉能力的测定研究

体育运动与运动知觉是分不开的，为了研究和探索运动训练对运动知觉能力的影响，我们测定了有训练——体育系学生的运动知觉能力，与无训练——普系学生的运动知觉能力，进行对比分析和研究．     

图像序列中运动目标深度估计

通过对生物视觉深度运动知觉机理的研究，推导出基于深度运动知觉提取三维运动目标深度信息的数学模型和计算公式．研究结果表明，根据三维运动目标在二维成像平面上的运动可以判断是否存在深度方向变化以及大致区分目标运动的方向．同时如果假定已知运动目标的大小，根据它们在像平面上ｘ或ｙ方向的相对运动变化可以对于目标的深度运动进行估计．经过采用实际图像序列所进行的实验，获得了令人满意的结果．     

图像序列中运动目标深度估计

通过对生物视觉深度运动知觉机理的研究，推导出基于度运动知觉提取三维运动目标深度信息的数学模型和计算公式，研究结果表明，根据三维运动目标在二维成像平面上的运动可以判断是否存在深度方向变化以及大致区分目标运动的方向，同时如果假定已知运动的大小，根据它们在像平面上ｘ或ｙ方向的相对运动变化可以对于目标的深度运动进行估计，经过采用实际图像序列所进行的实验，获得了令人满意的结果。     

外部噪音对弱视运动知觉影响的研究

以水平方向运动的垂直光栅作为视觉刺激,在对比了15名屈光参差性弱视患者和19名正常对照被试的运动方向辨别成绩后发现,弱视眼和非弱视眼的对比敏感度比值在添加噪音前后均不随时间频率变化,且在各个时间频率下外部噪音对弱视患者和正常人运动知觉的影响大致相当.这表明弱视运动知觉时间信息处理系统大致完好,对于理解弱视损伤机制和制定治疗方案都具有启示意义.     

知觉运动技能训练在排球运动中的应用

排球运动知觉学习是专门化的知觉技能训练过程,对该主题的研究有利于排球运动员认知运动技能的提高与发展.在前期文献基础上,对知觉技能进行了分类,探究了排球运动知觉学习的实质,整理并提出有关排球运动知觉学习的机制,对未来排球运动相关发展的影响因素进行了讨论.提出了针对排球知觉运动技能训练开展专门化知觉学习应着重解决的问题.     

软件人机界面设计的认知基础

从人类认知规律出发探讨了计算机软件界面的设计问题。分别介绍了软件界面设计中应考虑的刺激的颜色特性；运动知觉规律对软件界面设计的约束；刺激在软件界面上的呈现方式；视觉搜索的特点对软件界面上刺激布置的影响；短时记忆容量和软件界面设计的关系。     

助力法在智能训练中的作用

就如何馒体操运动知觉由模糊状态转化为明确状态提出了助力法智化训练。通过实验性研究，取得了比较显著的效果。     

男女大学生运动知觉能力的测定研究

本文研究结果表明:体育系学生无论男女,运动知觉能力明显高于普系学生,而且差异非常显著;只有上肢定位一项测验中,体育系男生与普系男生相比无明显差异。     

视觉伺服分类及其动态过程

对视觉伺服进行了综述性的介绍,系统地介绍了机器人视觉伺服控制的发展历史以及现状·从控制模型给出了视觉伺服控制系统的分类·针对两种最基本的分类方式基于位置的视觉伺服和基于图像的视觉伺服进行了重点介绍·对于视觉系统和图像特征的选取问题进行了讨论,此外还对视觉伺服系统的动态过程进行了分析,指出视觉系统的延时是目前伺服控制的研究所面临的最大问题·对未来视觉伺服研究的方向进行了总结·     

一种基于物联网的视觉系统设计

视觉系统主要是对运动物体或目标的检测和识别,如校园、交通、家庭等。该文主要是针对一种基于物联网的视觉系统采用模块化方法进行设计研究,并根据各个模块之间的逻辑工作顺序确定研究顺序。整体设计中,主要分为两大部分,一类是针对视觉系统的算法研究,另一类是系统硬件平台的设计研究。     

Hysteresis in the perception of motion direction as evidence for neural cooperativity

When elements of a parallel network, such as the human brain, are extensively interconnected, the network can exhibit 'cooperative behaviour'. Such behaviour, which is characterized by order-disorder transitions, multi-stable states, and a form of memory called 'hysteresis', has been observed in human stereopsis and has motivated models of stereopsis that incorporate cooperative networks. More recently, cooperative phenomena have also been observed in human visual motion perception. This report strongly supports a cooperative interpretation of motion perception by demonstrating hysteresis in the perception of motion direction. The results agree quantitatively with a mathematical model incorporating nonlinear excitatory and inhibitory interactions among direction-selective elements.     

Creating Autonomous, Perceptive and Intelligent Virtual Humans in a Real-Time Virtual Environment

Creating realistic virtual humans has been a challenging objective in computer science research for some time. This paper describes an integrated framework for modeling virtual humans with a high level of autonomy. The framework seeks to reproduce human-like believable behavior and movement in virtual humans in a virtual environment. The framework includes a visual and auditory information perception module, a decision network based behavior decision module, and a hierarchical autonomous motion control module. These cooperate to model realistic autonomous individual behavior for virtual humans in real-time interactive virtual environments. The framework was tested in a simulated virtual environment system to demonstrate the ability of the framework to create autonomous, perceptive and intelligent virtual humans in real-time virtual environments.     

Segregation of global and local motion processing in primate middle temporal visual area.

The early stages of primate visual processing appear to be divided up into several component parts so that, for example, colour, form and motion are analysed by anatomically distinct streams. We have found that further subspecialization occurs within the motion processing stream. Neurons representing two different kinds of information about visual motion are segregated in columnar fashion within the middle temporal area of the owl monkey. These columns can be distinguished by labelling with 2-deoxyglucose in response to large-field random-dot patterns. Neurons in lightly labelled interbands have receptive fields with antagonistic surrounds: the response to a centrally placed moving stimulus is suppressed by motion in the surround. Neurons in more densely labelled bands have surrounds that reinforce the centre response so that they integrate motion cues over large areas of the visual field. Interband cells carry information about local motion contrast that may be used to detect motion boundaries or to indicate retinal slip during visual tracking. Band cells encode information about global motion that might be useful for orienting the animal in its environment.     

Self-motion and the perception of stationary objects

One of the ways that we perceive shape is through seeing motion. Visual motion may be actively generated (for example, in locomotion), or passively observed. In the study of the perception of three-dimensional structure from motion, the non-moving, passive observer in an environment of moving rigid objects has been used as a substitute for an active observer moving in an environment of stationary objects; this 'rigidity hypothesis' has played a central role in computational and experimental studies of structure from motion. Here we show that this is not an adequate substitution because active and passive observers can perceive three-dimensional structure differently, despite experiencing the same visual stimulus: active observers' perception of three-dimensional structure depends on extraretinal information about their own movements. The visual system thus treats objects that are stationary (in an allocentric, earth-fixed reference frame) differently from objects that are merely rigid. These results show that action makes an important contribution to depth perception, and argue for a revision of the rigidity hypothesis to incorporate the special case of stationary objects.     

Visual motion and cortical velocity

Recent studies have revealed some remarkably simple relationships between visual performance and the neuroanatomy of the visual pathways. The visual field is mapped topographically on the surface of the striate cortex in man; the projection is large for the central visual field and is progressively compressed towards the periphery. Visual acuity decreases with distance from the fovea in proportion to the estimated cortical magnification factor, M (the extent of striate cortex in millimetres corresponding to a degree of arc in visual space). If a stimulus is magnified at peripheral locations in proportion to 1/M, it becomes equally resolvable across the visual field. This scaling procedure (M-scaling) maintains equivalence of the cortical projection of stimuli with different visual field loci. We have used M-scaling to investigate motion perception as a visual field variable. We report here that both the lower threshold of motion and adaptation to motion are uniform for M-scaled stimuli, and are related to the velocity of the 'cortical image'.     

Hearing visual motion in depth

Auditory spatial perception is strongly affected by visual cues. For example, if auditory and visual stimuli are presented synchronously but from different positions, the auditory event is mislocated towards the locus of the visual stimulus-the ventriloquism effect. This 'visual capture' also occurs in motion perception in which a static auditory stimulus appears to move with the visual moving object. We investigated how the human perceptual system coordinates complementary inputs from auditory and visual senses. Here we show that an auditory aftereffect occurs from adaptation to visual motion in depth. After a few minutes of viewing a square moving in depth, a steady sound was perceived as changing loudness in the opposite direction. Adaptation to a combination of auditory and visual stimuli changing in a compatible direction increased the aftereffect and the effect of visual adaptation almost disappeared when the directions were opposite. On the other hand, listening to a sound changing in intensity did not affect the visual changing-size aftereffect. The results provide psychophysical evidence that, for processing of motion in depth, the auditory system responds to both auditory changing intensity and visual motion in depth.     

视觉神经表征中底-顶和顶-底的双向激活——来自人与猴的实验证据

长期以来,建立在坚实生理学证据之上的底-顶加工说和特征检测理论在视觉研究中占主导地位。对于顶-底加工人们只能靠一般常识,即知识或经验通过激活记忆中的神经表征影响视觉过程。但是近年来,来自人和猴的研究为顶-底的加工提供了实验证据。 首先位于猴腹侧加工系统内的物体和面孔视觉记忆表征,提供了神经编码是怎样创立、组织和再激活的最佳实验证据。联想性编码是通过学习由一些具有特殊功能的神经元建立的,这些神经元具有将时间性关联刺激的表征联系起来的能力。其次,不仅来自视网膜的底-顶信号,而且来自前额叶的顶-底信号都能触发联想性编码的提取,既可以作为有意识回忆的神经基础,又是顶-底加工影响视觉过程的基础。脑损伤病人研究、具有高时间分辨率的人类功能性核磁共振成像(functional magnetic resonance imaging, fMRI)和猴fMRI研究以及猴细胞电生理分析相结合,将进一步加强人们对视觉脑机制的全面理解。     

A neural representation of depth from motion parallax in macaque visual cortex

Perception of depth is a fundamental challenge for the visual system, particularly for observers moving through their environment. The brain makes use of multiple visual cues to reconstruct the three-dimensional structure of a scene. One potent cue, motion parallax, frequently arises during translation of the observer because the images of objects at different distances move across the retina with different velocities. Human psychophysical studies have demonstrated that motion parallax can be a powerful depth cue, and motion parallax seems to be heavily exploited by animal species that lack highly developed binocular vision. However, little is known about the neural mechanisms that underlie this capacity. Here we show, by using a virtual-reality system to translate macaque monkeys (Macaca mulatta) while they viewed motion parallax displays that simulated objects at different depths, that many neurons in the middle temporal area (area MT) signal the sign of depth (near versus far) from motion parallax in the absence of other depth cues. To achieve this, neurons must combine visual motion with extra-retinal (non-visual) signals related to the animal's movement. Our findings suggest a new neural substrate for depth perception and demonstrate a robust interaction of visual and non-visual cues in area MT. Combined with previous studies that implicate area MT in depth perception based on binocular disparities, our results suggest that area MT contains a more general representation of three-dimensional space that makes use of multiple cues.     

Parallel processing of motion and colour information

When the two eyes are confronted with sufficiently different versions of the visual environment, one or the other eye dominates perception in alternation. A similar situation may be created in the laboratory by presenting images to the left and right eyes which differ in orientation or colour. Although perception is dominated by one eye during rivalry, there are a number of instances in which visual processes nevertheless continue to integrate information from the suppressed eye. For example the interocular transfer of the motion after-effect is undiminished when induced during binocular rivalry. Thus motion information processing may occur in parallel with the rivalry process. Here we describe a novel example in which the visual system simultaneously exhibits binocular rivalry and vision that integrates signals from both eyes. This apparent contradiction is resolved by postulating parallel visual processes devoted to the analyses of colour and motion information. Counterphased gratings are viewed dichoptically such that for one eye the grating is composed of alternating yellow and black stripes (luminance) while for the other it is composed of alternating red and green stripes (chrominance). When the gratings are fused, a moving grating is perceived. A consistent direction of motion can only be achieved if left and right monocular signals are integrated by the nervous system. Yet the apparent colour of the binocular percept alternates between red-green and yellow-black. These observations demonstrate the segregation of processing by the early motion system from that affording the perception of colour. Although, in this stimulus, colour information in itself can play no part in the cyclopean perception of motion direction, colour is carried along perceptually (filled in) by the moving pattern which is integrated from both eyes.     

一种基于线性回归模型的运动矢量重估算法

针对H.264/AVC空间分辨率缩减的视频转码,提出一种基于线性回归模型的运动矢量重估计算法.它利用原始视频流的运动矢量与下采样视频流的运动矢量之间的相关性,运用线性回归模型建模,得到下采样视频的运动矢量.仿真实验结果表明:在保持率失真性能的同时,计算复杂度明显降低.