计算机虚拟技术训练辅助盲人构建空间表征之研究

摘要 由于视觉经验的缺乏,盲人的空间认知存在一定的缺陷,尤其表现在对现实环境的空间布局认识存在困难。本研究欲探究计算机虚拟技术手段辅助盲人建构表征的成效,并在此基础上探究盲人定向行走的效果。本研究是一个现场实验,采用随机分配的方式将全盲被试分为三组,之后让被试接受三种不同的实验处理,即计算机虚拟技术、触觉地图和人导处理,最后接受空间任务测试,测试不仅考察被试对环境空间布局的认识,而且还测量了被试在现实环境的行走探路效率。结果发现,虚拟技术组的被试不仅能够对整个实验环境形成清晰整体的认识,而且还能借助形成的空间表征在测验场地有效地实施定向行走。从研究结果得知,计算机虚拟技术这一手段对应用于改善盲人空间表征系统及提高盲人定向行走训练效率具有一定的积极意义。     

认知控制在工作记忆表征引导注意中的作用:来自眼动的证据

研究同时采用首次注视点百分率与行为反应时指标,探讨了认知控制在无关工作记忆表征引导视觉注意选择过程中的作用。实验1发现:当视觉搜索容易时,首次注视点百分率和反应时指标都出现了注意引导效应;而当视觉搜索困难时,在反映早期注意定向的首次注视点百分率指标上,搜索快的被试组的注意引导效应显著大于搜索慢的被试组,而在行为反应时指标上,搜索快的被试组表现出注意引导效应,但搜索慢的被试组则表现出相反的注意拒绝效应。实验2发现当采用更为突显的靶子刺激时,首次注视点百分率指标上表现出的注意引导效应并未受到视觉搜索靶子显著性的影响,甚至还表现出一定的优先性。这些结果表明认知控制在工作记忆表征引导视觉注意的过程中所起的作用是动态变化的,视觉搜索早期注意定向阶段的注意引导效应比较稳健,认知控制只能减弱其效应的量值,而在随后的视觉搜索过程中,当视觉搜索比较缓慢时,认知控制可能会将注意引导效应反转为相反的注意拒绝效应。     

盲人的时间水平方向隐喻的通道特异性

通过2个实验, 考察了感觉通道对盲人的时间水平方向隐喻的影响。实验1发现, 盲人只在动作水平上存在同阅读方向一致的时间水平方向隐喻, 对表征过去的词或句子按左键反应和对表征将来的词或句子按右键反应时更快, 表明盲人用于隐喻时间的空间信息是知觉性的。实验2比较了明眼人可视组被试和明眼人遮眼组被试的时间空间隐喻, 发现明眼人可视组被试只在动作水平上存在时间水平方向隐喻, 明眼人遮眼组被试只在刺激在右侧时呈现才出现动作水平的时间水平方向隐喻。综合分析表明, 盲人和明眼人可视组被试的反应更为接近, 表明盲人的时间空间隐喻未受听觉信息的影响。盲人通过运动通道获得的空间认知代偿了视觉通道信息的缺失。     

右视野颜色范畴知觉是长期习得语言范畴还是即时分类颜色的结果?

本研究探讨了右视野颜色范畴知觉是由长期习得语言范畴还是即时分类颜色引起的。实验1让被试先将深绿、浅绿、浅蓝和深蓝四种颜色分为四种范畴,再接受视觉搜索任务。结果发现,视觉搜索任务中出现了与颜色分类相应的右视野颜色范畴知觉,且这一效应在任务的早段就表现出来,提示右视野颜色范畴知觉并非由分类颜色所引起。实验2让被试将四种渐进的蓝色分为两种范畴,并在之前与后接受视觉搜索任务。结果表明,分类后的视觉搜索中并未出现右视野颜色范畴知觉。先前研究表明,习得语言范畴使四种颜色为两种范畴后,颜色辨别会出现右视野范畴效应。因此,这一结果提示右视野颜色范畴知觉并非由分类颜色,而是由习得语言范畴所引起的。总体上,本研究提示右视野颜色范畴知觉是由长期习得语言范畴,而非即时分类颜色引起的,进一步揭示了语言与颜色知觉的关系。     

汉语句子理解中物体隐含颜色心理模拟的ERPs研究

当前研究采用事件相关电位(ERPs)技术,同时沿用经典的句图匹配范式,考察句子理解中物体典型颜色与非典型颜色的心理加工过程在脑电活动上的反映。实验中被试先阅读句子再判断句子后呈现的图片物体是否在句子中出现过,句子中隐含的物体颜色或是关键物体的典型颜色或是非典型颜色。实验结果发现,典型颜色句子版本下句图不匹配条件比句图匹配条件引发了更大的N400效应;而非典型颜色句子版本下两者N400差异不显著。研究结果表明,人们在汉语句子理解过程中会实时对隐含的物体颜色信息进行心理模拟。并且,句子隐含物体颜色的典型性是造成匹配易化或不匹配易化的关键因素之一。     

盲童心中的颜色概念及其组织

以黑、白、红、橙、黄、绿、蓝、紫、棕、灰、粉红11种基本颜色词为材料,运用颜色概念测试和颜色词分类的方法,研究了盲童的颜色概念及其组织。被试是85名盲校学生。结果表明：（1）盲童的颜色概念测试通过的顺序和明眼儿童的颜色命名的顺序既相似,又存在着差异;（2）盲童的基本颜色词的语义空间中有两个维度：①“彩色/非彩色”;②“实物色/背景色”。(3)盲童的颜色概念组织具有主题关联和slot-filler联系的性质,即根据自身的知识和经验,强调事物的功能、语境以及事件之间的联系     

偏侧化颜色范畴知觉不依赖于语言?

本研究探讨了偏左脑颜色范畴知觉依赖于语言还是范畴。三组被试分别完成无干扰、语言加工干扰和范畴加工干扰视觉搜索任务。结果发现：无干扰组、语言加工干扰组和范畴加工干扰组的视觉搜索任务中分别出现了偏左脑颜色范畴知觉、左脑劣势颜色范畴知觉和无偏侧化颜色范畴知觉。此结果表明,偏左脑颜色范畴知觉可能主要是语言范畴作为一种范畴对颜色知觉的影响效应,但语言范畴的语言属性也会对颜色知觉产生影响。     

文化差异影响彝、白、纳西和汉族大学生对黑白的认知

以彝族、白族、纳西族和汉族的大学生为被试,采用颜色相似性判断和颜色再认任务,考察了彝族、白族、纳西族和汉族的大学生对于黑色和白色的认知,意在探究不同民族的黑、白文化是否影响人们对黑、白颜色的认知。结果发现：⑴彝族、白族、纳西族和汉族的黑、白文化影响四个民族的大学生对于黑色和白色的认知;⑵语言和文化对于颜色认知的影响包括间接效应和直接效应。整个研究表明,语言和文化对颜色认知有重要影响     

刻板印象激活的无意图性及其大脑神经活动特征

采用启动Stroop范式, 对刻板印象激活的无意图性及其大脑神经活动特征进行了探讨。操纵了启动和“无启动”条件以及与启动所激活的刻板印象一致、冲突和无关的3类靶子词, 记录了36名大学生被试对靶子词进行颜色判别的行为反应和脑电图(EEG, electroencephalogram)。结果发现：(1)“无启动”条件下对3类靶子的反应时基本一致; 启动条件下对一致靶子做出颜色判别的反应时显著快于对冲突靶子的, 对无关靶子的反应时介于两者之间。(2)“无启动”条件下无关靶子诱发的N400波幅最大--显著大于一致和冲突靶子诱发的, 后两者诱发的N400无差异; 启动条件下一致靶子诱发的N400波幅显著小于冲突和无关靶子诱发的N400波幅, 无关靶子诱发的N400波幅也小于冲突靶子诱发的N400波幅。这表明刻板印象激活是一个发生在知觉后加工阶段的具有无意图性的自动化加工过程, 刻板印象激活效应具有抑制冲突信息加工同时促进一致信息加工的“双刃剑”模式, N400可以作为考察这一认知过程特征的电生理学指标。     

认知控制对基于位置和颜色返回抑制的影响

采用带颜色的字母为靶刺激.通过操纵被试任务.考察辨别任务中认知控制对基于位置和颜色IoR的影响.结果发现:要求被试辨别带颜色的字母,没有出现基于颜色的IoR;要求被试辨别颜色.出现了基于颜色的IoR.说明.自上而下的认知控制是基于颜色IoR产生的关键因素之一.其内在机制可用抑制模型和注意资源分配理论从不同角度解释.同时,两种任务均未要求被试辨别靶刺激的位置,却都出现了基于位置的IoR,验证了Russell"注意可能存在对位置信息自动加工"的假说.     

The role of visual experience on the representation and updating of novel haptic scenes

We investigated the role of visual experience on the spatial representation and updating of haptic scenes by comparing recognition performance across sighted, congenitally and late blind participants. We first established that spatial updating occurs in sighted individuals to haptic scenes of novel objects. All participants were required to recognise a previously learned haptic scene of novel objects presented across the same or different orientation as learning whilst they either remained in the same position to moved to a new position relative to the scene. Scene rotation incurred a cost in recognition performance in all groups. However, overall haptic scene recognition performance was worse in the congenitally blind group. Moreover, unlike the late blind or sighted groups, the congenitally blind group were unable to compensate for the cost in scene rotation with observer motion. Our results suggest that vision plays an important role in representing and updating spatial information encoded through touch and have important implications for the role of vision in the development of neuronal areas involved in spatial cognition.     

Haptic object matching by blind and sighted adults and children

The present study describes a tactual object matching task based on the study of Lederman and Klatzky (1987) for the dimensions Exact shape, Weight, Volume and Texture. Participants were congenitally blind children and their sighted classmates, congenitally blind adults and sighted adults. To study a possible effect of familiarity the task was performed four times. Based on Millar's CAPIN (Convergent Active Processes in Interrelated Networks) model of spatial processing (Millar, 1994) it was thought that this manipulation would add redundant information to the experiment from which the children and blind participants could benefit. The results showed that accuracy was affected more by age than visual status, especially for the dimension Exact Shape. With regard to response times, children were in most cases faster than adults, especially the sighted adults. Familiarization had a significant effect on response times for all dimensions. Extra exercise only increased accuracy for the dimension Texture. These results were generally in line with the CAPIN model.     

Sequential vs simultaneous encoding of spatial information: a comparison between the blind and the sighted

The aim of this research is to assess whether the crucial factor in determining the characteristics of blind people's spatial mental images is concerned with the visual impairment per se or the processing style that the dominant perceptual modalities used to acquire spatial information impose, i.e. simultaneous (vision) vs sequential (kinaesthesis). Participants were asked to learn six positions in a large parking area via movement alone (congenitally blind, adventitiously blind, blindfolded sighted) or with vision plus movement (simultaneous sighted, sequential sighted), and then to mentally scan between positions in the path. The crucial manipulation concerned the sequential sighted group. Their visual exploration was made sequential by putting visual obstacles within the pathway in such a way that they could not see simultaneously the positions along the pathway. The results revealed a significant time/distance linear relation in all tested groups. However, the linear component was lower in sequential sighted and blind participants, especially congenital. Sequential sighted and congenitally blind participants showed an almost overlapping performance. Differences between groups became evident when mentally scanning farther distances (more than 5m). This threshold effect could be revealing of processing limitations due to the need of integrating and updating spatial information. Overall, the results suggest that the characteristics of the processing style rather than the visual impairment per se affect blind people's spatial mental images.     

Superior haptic perceptual selectivity in late-blind and very-low-vision subjects

Blindfolded sighted, congenitally blind, late-blind, and very-low-vision subjects were tested on a tangible version of the embedded-figures test. The results of ANOVAs on accuracy measures yielded superior performance by the very-low-vision and late-blind subjects compared with the blindfolded sighted and congenitally blind participants. Accuracy of the congenitally blind subjects was similar to that of the blindfolded sighted participants. However, all groups of blind subjects were significantly faster than the blindfolded sighted subjects. It is suggested that experience with pictures combined with haptic skill aid perceptual selectivity in touch.     

Hearing cheats touch, but less in congenitally blind than in sighted individuals

Abstract— The principles of cross-modal integration were investigated with an auditory-tactile illusion in sighted and congenitally blind adults. Participants had to judge the number of rapidly presented tactile stimuli, which were presented together with task-irrelevant sounds. When one tactile stimulus was accompanied by more than one tone, participants reported perceiving more than a single touch. This illusion was more pronounced in sighted than congenitally blind participants. Given that the congenitally blind were more precise in judging the number of tactile stimuli in a control condition without tones, the present data are in accordance with a modality-appropriateness account suggesting that interference by a task-irrelevant modality is reduced if processing accuracy of the task-relevant modality is high.     

Haptic perception of the horizontal by blind and low-vision individuals.

We examined haptic perception of the horizontal in visually impaired people. Blind people (late blind and congenitally blind), persons with very low vision, and blindfolded sighted individuals felt raised-line drawings of jars at four angles. They had to demonstrate their understanding that water remains horizontal, despite jar tilt, by selecting the correct raised-line drawing given four choices. Low-vision subjects, with near perfect scores, performed significantly better than the other groups of subjects. While the late-blind and blindfolded sighted subjects performed slightly better than the congenitally blind participants, the difference between the late-blind and congenitally blind groups was nonsignificant. The performance of the congenitally blind subjects indicates that visual experience is not necessary for the development of an understanding that water level stays horizontal, given container tilt.     

Mental imagery,reasoning, and blindness

Although reasoning seems to be inextricably linked to seeing in the “mind's eye”, the evidence is equivocal. In three experiments, sighted, blindfolded sighted, and congenitally totally blind persons solved deductive inferences based on three sorts of relation: (a) visuo-spatial relations that are easy to envisage either visually or spatially, (b) visual relations that are easy to envisage visually but hard to envisage spatially, and (c) control relations that are hard to envisage both visually and spatially. In absolute terms, congenitally totally blind persons performed less accurately and more slowly than the sighted on all such tasks. In relative terms, however, the visual relations in comparison with control relations impeded the reasoning of sighted and blindfolded participants, whereas congenitally totally blind participants performed the same with the different sorts of relation. We conclude that mental images containing visual details that are irrelevant to an inference can even impede the process of reasoning. Persons who are blind from birth—and who thus do not tend to construct visual mental images—are immune to this visual-impedance effect.     

Mental imagery, reasoning, and blindness

Although reasoning seems to be inextricably linked to seeing in the “mind's eye”, the evidence is equivocal. In three experiments, sighted, blindfolded sighted, and congenitally totally blind persons solved deductive inferences based on three sorts of relation: (a) visuo-spatial relations that are easy to envisage either visually or spatially, (b) visual relations that are easy to envisage visually but hard to envisage spatially, and (c) control relations that are hard to envisage both visually and spatially. In absolute terms, congenitally totally blind persons performed less accurately and more slowly than the sighted on all such tasks. In relative terms, however, the visual relations in comparison with control relations impeded the reasoning of sighted and blindfolded participants, whereas congenitally totally blind participants performed the same with the different sorts of relation. We conclude that mental images containing visual details that are irrelevant to an inference can even impede the process of reasoning. Persons who are blind from birth—and who thus do not tend to construct visual mental images—are immune to this visual-impedance effect.