Perceptual learning without perception.

The brain is able to adapt rapidly and continually to the surrounding environment, becoming increasingly sensitive to important and frequently encountered stimuli. It is often claimed that this adaptive learning is highly task-specific, that is, we become more sensitive to the critical signals in the tasks we attend to. Here, we show a new type of perceptual learning, which occurs without attention, without awareness and without any task relevance. Subjects were repeatedly presented with a background motion signal so weak that its direction was not visible; the invisible motion was an irrelevant background to the central task that engaged the subject's attention. Despite being below the threshold of visibility and being irrelevant to the central task, the repetitive exposure improved performance specifically for the direction of the exposed motion when tested in a subsequent suprathreshold test. These results suggest that a frequently presented feature sensitizes the visual system merely owing to its frequency, not its relevance or salience.     

Predictable eye-head coordination during driving.

Large changes in the direction of gaze are made with a combination of fast saccadic eye movements and rather slower head movements. Since the first study on freely moving subjects, most authors have agreed that the head movement component of gaze is very variable, with a high 'volitional' component. But in some circumstances head and eye movements can be quite predictable, for example when a subject is asked to shift gaze as quickly as possible. Under these conditions, laboratory studies have shown that the eye and head motor-systems both receive gaze-change commands, although they execute them in rather different ways. Here I reconsider the way gaze direction is changed during free movement, but in the performance of a task where the subject is too busy to exert conscious control over head or eye movements. Using a new portable and inexpensive method for recording head and eye movements, I examine the oculomotor behaviour of car drivers, particularly during the large gaze changes made at road junctions. The results show that the pattern of eye and head movements is highly predictable, given only the sequence of gaze targets.     

Perceptual learning of dot pattern

Dot pattern is a type of pattern defined by specific spatial relationship among some dots. As a compensation for concrete and meaningful visual stimuli, meaningless dot pattern can be used as stimuli in learning tasks. We performed an experiment for exploring the perceptual learning process of dot pattern against random-dot background. Participants were required to learn two types of dot patterns (9-dot and 11-dot). They were assigned to two groups: participants in Group 1 learned 9-dot pattern first and 11-dot pattern later, while those in Group 2 learned 11-dot pattern first and 9-dot pattern later. The results showed that participants could acquire the spatial relationship of dot pattern through perceptual learning in relatively short learning time. In comparison with 9-dot pattern, learning time of 11-dot pattern was slightly longer and its accuracy rate lower, but there was significant positive transfer effect from 11-dot pattern learning to 9-dot learning.     

Perceptual learning of dot pattern

Dot pattern is a type of pattern defined by specific spatial relationship among some dots. As a compensation for concrete and meaningful visual stimuli, meaningless dot pattern can be used as stimuli in learning tasks. We performed an experiment for exploring the perceptual learning process of dot pattern against random-dot background. Participants were required to learn two types of dot patterns (9-dot and 11-dot). They were assigned to two groups: participants in Group 1 learned 9-dot pattern first and 11-dot pattern later, while those in Group 2 learned 11-dot pattern first and 9-dot pattern later. The results showed that participants could acquire the spatial relationship of dot pattern through perceptual learning in relatively short learning time. In comparison with 9-dot pattern, learning time of 11-dot pattern was slightly longer and its accuracy rate lower, but there was significant positive transfer effect from 11-dot pattern learning to 9-dot learning.     

思维分类理论研究述评

分类是一项非常重要的认知活动。通过分类活动,人们能够在一定程度上推知某一事物的未知特征,并作出预测。因而分类研究一直是现代心理学研究的重点和热点。回顾分类研究的历程,可把分类研究划分为两个领域。一是从实证的角度探讨分类活动内部的心理机制;一是从理论的角度概括分类活动的研究成果,提出分类的理论依据和模型。这些理论和模型主要围绕相似观和解释观来建构的,这两种观点都有一些实验证据的支持,但也都存在一些不足。因此,近年来,研究者又提出一些新的分类理论与模型。     

加强对学生感性认识的培养

让一年级的学生在入学的第一学期就来实验室做一些简单的基础性实验,对培养学生科学求实的学习态度,保持良好的工作作风,增强安全意识,以及激发学生浓厚的学习兴趣,给后续实验打下良好的基础等方面均收到了良好的效果。     

不同知觉负载条件下的无意视盲

采用静态研究范式研究无意视盲的负载问题。结果发现:(1)在低负载和高负载的条件下都有无意视盲现象出现,而且二者的比例无显著性差异;(2)出现无意视盲的被试,其主任务完成情况不受非预期刺激的影响,而注意到非预期刺激的被试则因非预期刺激的出现,反应时延长,正确率下降。     

基于视觉颜色聚类的彩色图像分割

根据视觉的颜色聚类特性，提出一种图像分割算法．根据从色彩空间(RGB)到(HLC)的变换公式和NBS颜色距离的概念，首先将彩色图像量化为256或更少量化级，而不使图像质量降低；然后依据NBS颜色距离的概念将色彩分类；最后，根据某种规则将颜色区域进行分块，并删除小的颜色块．给出了静物图像和自然景物图像的实验结果。     

论广告创意的感性诉求

创意是广告的灵魂,广告创意是对广告作家能力的挑战,它要求广告作家要思考而不能只乞求于灵感,并要符合创意的基本要求.商业广告中的感性诉求是根植于受众的情感,为达到迎合受众情感的目的,提出了一些感性诉求广告创作的新思维及其遵循的一般原则.     

马克思的感性自然观与环境伦理学

当代环境伦理学存在的主要问题是：没有摆脱合法性困境;在人学和自然问题上存在双重误读。马克思的感性自然观从人与自然的对象性关系出发,能够为环境伦理学摆脱合法性困境寻求一条可能的逻辑通道。     

语音合成中基于听辨指导的权重训练算法

针对语音合成的基元选取中权重设定的问题提出了一种基于人工听辨指导的权重自动训练的方法。该方法首先通过人工听辨对现有的基元选取结果进行评测打分,然后采取韵律逼近的方法对人工评测的结果进行学习,进而对权重进行调整修正,从而实现权重的自动训练。实验表明:该方法较好地解决了权重设定的问题,使得合成语音的自然度听辨得分由3.49提高到4.02。同时,该方法还使得语音合成系统在使用过程中根据用户反馈自动进行优化成为可能。     

面向基于内容图像检索的图像感知Hash

提出一种建立在HSV空间颜色分类和形态特征基础上的图像Hash方法,用于图像检索.将图像尺寸规格化,并根据HSV空间中各分量的取值范围,将像素归为11类,在各类颜色成分中提取亮度、大小、形态等特征,加权得到Hash值以构成图像库的索引表,从而实现基于内容的图像检索(content-based image retrieval,CBIR).与其他方法相比,用该方法提取的图像特征除颜色外还包含形态特征,能较好地体现图像内容.实验结果表明,该方法具有良好的性能.     

基于感性意象的投影仪造型设计

以投影仪的产品外观造型为例,通过语义差异法研究用户对产品造型风格的感性认知,并对用户感性认知进行因子分析,找出影响用户感性认知的主成分因子.通过口语分析、形态分析法,找出影响投影仪外观造型的权重因子:机身外壳、镜头、散热格栅/孔、辅助线面、红外接收器.研究表明,用户的内隐性感性认知可以通过语义差异方法外显化.     

Neurophysiological investigation of the basis of the fMRI signal.

Functional magnetic resonance imaging (fMRI) is widely used to study the operational organization of the human brain, but the exact relationship between the measured fMRI signal and the underlying neural activity is unclear. Here we present simultaneous intracortical recordings of neural signals and fMRI responses. We compared local field potentials (LFPs), single- and multi-unit spiking activity with highly spatio-temporally resolved blood-oxygen-level-dependent (BOLD) fMRI responses from the visual cortex of monkeys. The largest magnitude changes were observed in LFPs, which at recording sites characterized by transient responses were the only signal that significantly correlated with the haemodynamic response. Linear systems analysis on a trial-by-trial basis showed that the impulse response of the neurovascular system is both animal- and site-specific, and that LFPs yield a better estimate of BOLD responses than the multi-unit responses. These findings suggest that the BOLD contrast mechanism reflects the input and intracortical processing of a given area rather than its spiking output.