自闭症谱系障碍者的视运动知觉

视运动知觉是人脑对外界物体的运动特性的知觉。视运动知觉异常是自闭症谱系障碍者的一种常见表现, 其检测光流、二阶运动、协同性运动、生物运动及运动速度的能力异于健康控制组, 且过度迷恋重复性运动物体。该群体视运动知觉异常的原因探析集中于背侧/M细胞通路特定假设、复杂性假设、神经噪声假设、经验缺失假设、时空加工异常假设、极端男性脑理论和社会脑假设。但到目前为止, 尚缺乏一个统一准确的、可验证的解释。未来研究应注重考察自闭症者视运动知觉异常的个体差异和神经生理机制, 进一步整合和验证解释理论, 并着眼开发有效的视运动知觉测评工具和干预策略     

视觉运动知觉脑机制的研究现状

视觉运动是探索脑功能的一个重要研究途径,该对视觉运动通路与色彩的关系、视觉运动知觉的产生,对于视觉信息的不同阶段的处理以及立体视觉等若干问题进行了回顾与讨论,并概述了其中若干理论及其争论,提出了未来视觉研究可能存在的问题与研究方向。     

颜色词与颜色认知的关系

颜色词作为一个特殊词类,是探讨语言与认知关系的重要途径。文章综述了颜色知觉和颜色词分类等领域的研究,重点介绍了有关颜色词与认知的两种理论：颜色词的普遍进化理论和语言关联性假设,前者认为颜色词与颜色认知是相对独立的,后者认为语言与认知相互影响。文章综述了与这两种理论有关的一些最新研究进展,并对该领域研究提出一些新的研究思路,如研究颜色词的联想意义、颜色词与民族心理、复合颜色词的加工及对认知的影响、通感现象、颜色词的概念组织等。     

腹侧通路与背侧通路在词汇阅读中的作用

腹侧通路与背侧通路是视觉加工的两条通路。随着认知神经科学的发展,研究发现腹侧和背侧通路与词汇阅读有关。其中腹侧通路与词汇识别有关,背侧通路与阅读的关系比较复杂。本文简要回顾了两条通路在词汇阅读中的作用。     

颜色词与颜色认知的关系——基于民族心理学的研究视角

颜色词与颜色认知的关系是语言影响认知的重要领域.不同民族之间存在着语言和文化的差异.对于颜色词与颜色认知的关系,一直就存在着普遍进化理论和语言相对论的争论.既往研究通过哲学思辨、命名和计算、颜色分类、颜色记忆和颜色搜索等多种范式对颜色词与颜色认知的关系进行了卓有成效的探讨,使该领域的研究呈现出蓬勃发展的局面.     

场景在价值驱动注意捕获中的作用

本研究采用训练-测试范式考察场景信息在价值驱动注意捕获中的作用。实验1训练阶段将唯一性的场景信息与奖励建立联结,测试阶段发现只有当分心刺激出现在高奖励场景中才能捕获注意;实验2训练阶段将场景和颜色信息联合但分别独立预测奖励,结果发现高奖励颜色出现在任何场景中都能捕获注意。研究结果表明:(1)场景-价值联结能够引发注意捕获效应;(2)与场景相比,颜色特征在价值驱动的注意捕获中具有优势效应。     

生物运动加工特异性：整体结构和局部运动的作用

人类具有很强的识别生物体运动信息的能力, 甚至当运动信息仅是由附着在头部和一些重要关节上的光点的运动组成时, 观察者对该信息检测和编码的优势依然存在。光点生物运动信息包含整体信息(如整体形状)和局部信息(如各个点的运动轨迹)。先前的绝大部分研究强调整体形状在生物运动知觉中的作用。最近有研究表明去除了整体结构信息的局部生物运动仍然存在加工优势, 揭示了局部生物运动本身可能包含了一些特异性信息。因此生物运动知觉并非单一现象, 而是一种具有不同加工机制(基于整体结构和基于局部运动)的多水平现象。     

语言对知觉的影响—— 来自颜色范畴知觉研究的证据

介绍了近年来语言和颜色范畴知觉关系研究的新进展, 特别是颜色范畴知觉效应的偏侧化、婴幼儿颜色范畴知觉的特点等。同时指出了今后需要进一步研究的问题, 如颜色范畴知觉效应偏侧化与语言的关系、右脑语言优势者颜色范畴知觉的特点、颜色加工脑区和语言加工脑区之间的关系以及婴幼儿颜色范畴知觉特点的追踪研究等。     

威胁性信息检测的脑机制

快速而准确地检测威胁性信息是进化过程中形成的一种重要能力,是有效应对危险的前提条件,对有机体的生存具有重要价值.威胁性信息的检测由不同的神经通路合作完成.在视觉通道中,皮层通路的精确检测和皮层下通路的快速检测在杏仁核得到整合.杏仁核能接受多感觉通道的信息输入,并接受额叶的调节,是威胁性信息加工中连通自上而下加工和自下而上加工的枢纽.将来的研究需要进一步关注杏仁核的功能以及不同的神经通路如何合作完成威胁性信息的检测.     

宗教对信徒颜色认知的影响及作用机制:以中国台湾宗教信徒为例

采用自然分类法考察中国台湾佛教徒、道教徒、基督徒和非宗教信徒的基本颜色词分类,并做多维标度和聚类分析,以揭示宗教对信徒颜色认知的影响。结果发现,中国台湾三大宗教信徒对基本颜色词的分类既具有共性,又存在差异,宗教信徒与非宗教信徒的基本颜色词分类也存在着共性和差异,共性反映了汉语言和汉文化的影响,差异反映了宗教对颜色认知的影响。研究表明,颜色通过意象式传播方式影响信徒的颜色认知,支持颜色词与颜色认知的相互作用理论。     

Chromatic perception in relation to an hypothesized cerebral dominance

On the basis of the cerebral dominance, we have hypothesized an asymmetry (for saturation or brightness) between the two eyes in perception of chromatic stimuli. 51 subjects were tested on chromatic perception (green, red, yellow, blue). For each subject also an ocular-dominance score was obtained. The results substantially confirmed the hypothesis of cerebral dominance in color perception. Subjects with high ocular-dominance scores (right- or left-dominant subjects) showed for the green stimulus asymmetric behavior, while subjects with low ocular-dominance scores showed a tendency toward symmetry in perception.     

The effect of red color on perceived self‐attractiveness

Recent research showed that individuals are perceived as more attractive when presented with the color red. We seek to extend these findings by studying the effects of red color on individuals' perception of self‐attractiveness, rather than the attractiveness of others. Based on the color‐in‐context theory, we hypothesized that individuals would perceive themselves as more attractive under red chromatic conditions. In three experiments, participants were asked to wear a red or a blue shirt and rated their own attractiveness. As expected, participants in the red shirt condition indicated a higher level of self‐attractiveness than participants in the blue condition. Moreover, the results showed that the self‐perception red effect was mediated by the individuals' self‐perceived sexual receptivity and self‐perceived status.     

Hue distinctiveness overrides category in determining performance in multiple object tracking

The visual distinctiveness between targets and distractors can significantly facilitate performance in multiple object tracking (MOT), in which color is a feature that has been commonly used. However, the processing of color can be more than “visual.” Color is continuous in chromaticity, while it is commonly grouped into discrete categories (e.g., red, green). Evidence from color perception suggested that color categories may have a unique role in visual tasks independent of its chromatic appearance. Previous MOT studies have not examined the effect of chromatic and categorical distinctiveness on tracking separately. The current study aimed to reveal how chromatic (hue) and categorical distinctiveness of color between the targets and distractors affects tracking performance. With four experiments, we showed that tracking performance was largely facilitated by the increasing hue distance between the target set and the distractor set, suggesting that perceptual grouping was formed based on hue distinctiveness to aid tracking. However, we found no color categorical effect, because tracking performance was not significantly different when the targets and distractors were from the same or different categories. It was concluded that the chromatic distinctiveness of color overrides category in determining tracking performance, suggesting a dominant role of perceptual feature in MOT.     

Color correspondence in apparent motion

To maintain figural identity during motion perception, the visual system must match images over space and time. Correct matching requires a metric for identifying "corresponding" images, those representing the same physical object. To test whether matching is based on achromatic (black/white) polarity and chromatic (red/green) color, observers viewed an ambiguous motion display and judged the path of apparent motion. Matching preserved black/white identity regardless of whether frames were viewed binocularly or dichoptically. Red/green identity was also preserved, but coherence of motion depended in part on the number of frames in the motion sequence and on the background luminance. These results suggest that correspondence is computed by a weighted metric containing terms for image features coded early in visual processing.     

Richer color experience in observers with multiple photopigment opsin genes

Traditional color vision theory posits that three types of retinal photopigments transduce light into a trivariate neural color code, thereby explaining color-matching behaviors. This principle of trichromacy is in need of reexamination in view of molecular genetics results suggesting that a substantial percentage of women possess more than three classes of retinal photopigments. At issue is the question of whether four-photopigment retinas necessarily yield trichromatic color perception. In the present paper, we review results and theory underlying the accepted photoreceptor-based model of trichromacy. A review of the psychological literature shows that gender-linked differences in color perception warrant further investigation of retinal photopigment classes and color perception relations. We use genetic analyses to examine an important position in the gene sequence, and we empirically assess and compare the color perception of individuals possessing more than three retinal photopigment genes with those possessing fewer retinal photopigment genes. Women with four-photopigment genotypes are found to perceive significantly more chromatic appearances in comparison with either male or female trichromat controls. We provide a rationale for this previously undetected finding and discuss implications for theories of color perception and gender differences in color behavior.     

Fertile green: green facilitates creative performance

The present research sought to extend the nascent literature on color and psychological functioning by examining whether perception of the color green facilitates creativity. In four experiments, we demonstrated that a brief glimpse of green prior to a creativity task enhances creative performance. This green effect was observed using both achromatic (white, gray) and chromatic (red, blue) contrast colors that were carefully matched on nonhue properties, and using both picture-based and word-based assessments of creativity. Participants were not aware of the purpose of the experiment, and null effects were obtained on participants' self-reported mood and positive activation. These findings indicate that green has implications beyond aesthetics and suggest the need for sustained empirical work on the functional meaning of green.     

Purely chromatic perception of motion in depth: two eyes as sensitive as one

Motion hyperacuity (phase) thresholds were measured for both lateral and stereoscopic oscillatory motion in both luminance and equiluminant red/green gratings of 2 cycles per degree. Thresholds for lateral chromatic motion did not exhibit the inhibitory fall-off at low temporal frequencies that was found for luminance motion. Phase thresholds for purely chromatic motion were substantially higher than those for luminance gratings, in proportion to the ratio of cone signal modulation, but they could be predicted from the corresponding contrast sensitivities for both types of stimulus. Stereomovement thresholds in luminance gratings showed the stereomovement suppression effect relative to monocular motion sensitivity previously reported for line stimuli, but purely chromatic gratings did not. Together with the lack of an inhibitory fall-off, these results imply that chromatic and luminance motion are processed by different neural pathways, and that the chrominance pathway is capable of supporting a strong percept of stereoscopic motion from purely chromatic gratings.     

Perception of chromatic motion requires luminance interaction

There is an ongoing debate related to whether chromatic motion perception arises as a consequence of a chromatic signal only (eg Wandell et al 1999 Neuron 24 901-909) or a signal that is essentially based on luminance processes (luminance artifacts) (Mullen et al 2003 Vision Research 43 1235-1247). These two views conform to the idea that colour and luminance processes are physiologically independent (Livingstone and Hubel 1988 Science 240 740-749), but according to other reports many primary cortical 'V1' cells respond to both colour and luminance contrast (eg Vidyasagar et al 2002 European Journal of Neuroscience 16 945-956). A psychophysical task was designed to test whether possible interaction between luminance and chromatic contrast could account for perception of chromatic motion. It is shown that subjects respond in a manner that reflects involvement of both processes.     

Opponent chromatic response functions for an average observer

Average opponent chromatic response functions are presented for use in quantitative models of color perception. Theoretical transformations of photopigment input are related to opponent channel activity. Opponent chromatic activity is, in turn, used to describe a theoretical huenaming curve for an average observer.     

Color categories and color appearance

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue-green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses.