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1.
人类颜色视觉的计算理论   总被引:2,自引:0,他引:2  
该文有机地结合了计算视觉理论和生态学视觉理论,指出颜色信息处理的根本任务是检测环境中的光不变量。在此基础上,作者提出了颜色视觉的计算理论以及计算理论本身的生物学标准。初级视觉计算是典型的不适定问题,动物的视觉系统则利用视环境中存在的条件将该不适定问题转化为定解问题。本文引入颜色视觉计算的免要条件,客观性约束,以及颜色认知的神经表象,证明了上述约束下颜色算法的存在性。本文给出了构造颜色知觉的基本假设。同时,该文还讨论了与上述问题密切相关的几个基本问题:神经表象的完备性,主观色觉的客观性,明度知觉和颜色知觉的统一,人类主观色觉的实现方式。  相似文献   
2.
This study examined how preschool inattention-hyperactivity is related to elementary school reading achievement. Prereading skills were hypothesized to be a link between them. This link was explored using longitudinal data on 105 low-socioeconomic-status (SES) children's inattentive-hyperactive behavior and prereading skills in Head Start and in kindergarten and their inattentive-hyperactive behavior and reading skills in first grade. A model of this relationship was tested using structural equation modeling. The results failed to show a significant path between inattention-hyperactivity and prereading skills at both the Head Start and kindergarten levels. A significant path was found between first grade inattention-hyperactivity and reading skills, confirming that the strong relationship between inattention-hyperactivity and poor reading achievement commonly found in children from other SES levels was also significant in this low-SES sample. Strong relationships were found between pre-reading skills and reading skills, as well as among hyperactivity levels at the three grades. The issue of the direction of the path of influence between attention-behavior and reading achievement is addressed briefly; however, the results indicate that further longitudinal work is necessary to resolve this issue.  相似文献   
3.
The advantages of presenting sensory data in terms of stimulus variables are stressed. Spectral sensitivity plots of local electroretinograms and ganglion cell discharges from the dark-adapted rabbit retina illustrate the utility of using this kind of procedure. Spectral data agreed with the literature demonstrating two cone and one rod process in this animal. The spectral sensitivities of both the local electroretinogram and ganglion cell spikes were closely similar. Data pertaining to pattern vision may also be subjected to the same type of analysis and described in terms of stimulus variables.  相似文献   
4.
Key pecking and treadle pressing in pigeons were compared under concurrent (key-treadle) and single-operant differential-reinforcement-of-low-rate schedules of food reinforcement ranging from 5 to 60 sec (concurrent procedure) or 5 to 120 sec (single-operant procedure). Under both procedures, the two operants followed the same general law: decreasing response rate and reinforcement rate and increasing number of responses per reinforcement as a function of increasing schedule interval. High correlations were found between key pecking and treadle pressing for the measures of response rate, reinforcement rate, and responses per reinforcement. Regression equations allowed the prediction of treadle pressing from key pecking. More bursting occurred in responding to the key, and key pecking showed a more precise temporal discrimination than treadle pressing. A test for sequential dependencies between key and treadle responses showed significant dependencies not only under the concurrent procedure but also in data created artificially by merging key and treadle sequences from different pigeons under the concurrent procedure and from the same pigeon under the single-operant procedure. It seems likely that the sequential dependencies found were due to the independent action of the schedule on each operant and that behavioral dependencies did not occur with the concurrent training procedure. The key-peck operant does not appear to have any special qualities that preclude its use in discovering general laws of behavior, at least under the differential-reinforcement-of-low-rate schedule. The usefulness of the key peck in other situations requires direct experimental study.  相似文献   
5.
A paradigm for the control of visual fixation of the macaque monkey in vision experiments was described. Using a Maxwellian view, the procedure permits the placement of discrete test-light stimuli in a specific area of the retina as the monkey fixates a primary target. This procedure holds foveal fixation as other behaviorally significant visual stimuli are presented to the visual field. By a methods-of-limits procedure, the sensitivity of the monkey eye was measured at different retinal locations under both photopic and scotopic visual adaptation.  相似文献   
6.
生命教育作为高等医学教育的一个重要组成部分,已经得到了广泛认可。然而,在现阶段由于实践上的片面强调以及理论上的粗浅阐释,关于生命教育的研究仍是处在一个有待深化与拓展的层次。而从哲学的视野开拓对生命教育的认知,进而从中西方哲学会通的视野深化这一认知并挖掘其思想传统与相互的共鸣之处,则是对这一现状的积极回应。它具有非常重要的必要性,也有助于深化对生命教育的认知与提升对生命教育的实践。  相似文献   
7.
Under numerous circumstances, humans recognize visual objects in their environment with remarkable response times and accuracy. Existing artificial visual object recognition systems have not yet surpassed human vision, especially in its universality of application. We argue that modeling the recognition process in an exclusive feedforward manner hinders those systems’ performance. To bridge that performance gap between them and human vision, we present a brief review of neuroscientific data, which suggests that considering an agent’s internal influences (from cognitive systems that peripherally interact with visual-perceptual processes) recognition can be improved. Then, we propose a model for visual object recognition which uses these systems’ information, such as affection, for generating expectation to prime the object recognition system, thus reducing its execution times. Later, an implementation of the model is described. Finally, we present and discuss an experiment and its results.  相似文献   
8.
刘洪广  周琳 《心理科学》2006,29(2):366-369
研究视觉分别搜索在左右视野靶时,脑两侧前额叶视觉加工的机制。14名有偿被试参加实验。实验任务是从正圆中所存在的垂直方向的箭头,搜索出水平方向箭头,并判断箭头方向。靶所在左右视野经过镜面处理完全对应。结果发现当靶出现约220ms后左右两侧脑区ERP出现分叉点,靶对侧与靶同侧的前脑区相比有非常显著的负向电位活动,对侧和同侧的N2延续40-80ms。分析认为靶对侧前额脑区N2负向活动增强是注意的等级提高,聚焦点收窄,使所要加工的靶在主效应脑区(靶视野对侧脑区)“跃显”出来,在得到正反馈诱导的同时,也得到更多的资源,靶同侧脑区N2可能与中断或阻止其他无关信息的涌入有关。  相似文献   
9.
低出生体重是发生成年期代谢综合征的高危因素。“代谢程序化”与“营养程序化”概念的提出对人们从多层面认识该现象的内在机制有重要指导作用。随着对发生机制研究的深入,人们终将找到预防低出生体重发生成年期代谢综合征的早期干预措施。  相似文献   
10.
This study examined adolescents with low vision (LV) compared to students without disabilities regarding their cyberbullying experiences, as related to perceived social support. Sample consisted of 407 students (61 with LV) who completed self-reported questionnaires. Findings revealed that students with LV are using the computer and the Internet as much as the typical students, but students with LV had less frequent Internet interactions with friends. Students with LV reported being more involved in cyberbullying as cybervictims, cyberperpetrators, cyberwitnesses, knowing someone and telling their online experience to another, and having lower social support compared to students without disabilities. Students with LV are more willing to report and to share their online experiences with another person. The findings add to our knowledge about students’ experiences of cyberbullying and suggest implementing effective coping strategies programs to raise the awareness of cyberbullying risky behavior.  相似文献   
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