视觉搜索中等概率目标觉察的扫视模式

视觉搜索是许多作业活动中的重要组成成份,对视觉搜索中扫视策略的研究有助于了解人的信息加工过程。本实验利用眼动测量技术记录了等目标概率下视觉搜索的眼动过程,以了解目标觉察时的扫视模式。结果表明,当目标概率相等时,注视点的分布与目标概率的分布一致,平均注视时间主要在240-320ms 之间。被试的扫视模式存在着统计依存性,即具有固定的扫视模式。时间序列分析结果表明扫视模式也表现在下一个注视点的位置取决于以前数个注视点的位置,可用 ARMA(2.2)或 ARMA(3.3)拟合。频谱分析结果表明被试使用相同的低频扫视模式。     

道路交通标志中对称结构效应的眼动研究

本研究考察了道路交通标志中路名信息对称结构效应的眼动模式。实验采用眼动跟踪技术和视觉搜索范式,共有16名被试参加。实验结果表明：（1）在对称结构路名信息的视觉搜索中,被试的反应正确率明显优于非对称结构条件下的正确率;（2）对称结构条件下,被试的注视点和回扫次数明显较少,凝视时间明显较短;（3）在以道路交通标志为视觉搜索材料时,搜索区有无路名目标对视觉搜索绩效没有影响。可以认为：在道路交通标志中存在对称结构效应;眼动模式的差异是引起对称结构效应的认知机制。     

目标概率对视觉搜索中扫视模式的影响

对扫视模式的研究有助于了解人类信息加工过程。本研究利用眼动测量技术记录了视觉搜索中的眼动过程,以了解目标概率对目标觉察中扫视模式的影响。实验结果表明不同的目标概率会引起平均注视时间长短的变化;注视点分布不但与目标概率有关,而且受被试所用的扫视策略影响;时间序列分析结果表明以前数个注视点的位置对下一个注视点位置的影响可用低阶的 AR 或 ARMA 过程来表示。频谱分析结果表明在目标概率不同时被试会使用不同的扫视模式,扫视模式在 X 方向和 Y 方向也不相同。研究表明时间序列分析是一种分析扫视模式的较好方法。     

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。     

人脸图形识别取样的眼动特征

通过眼动数据的分析,探讨人脸图形识别的取样特征。实验为2×2的被试内设计,自变量为显示条件（良好显示和不良显示）和显示方式（旋转显示和非旋转显示）。实验的因变量有反应时、总注视时间、注视比率、首视点注视时间、注视点数量、扫视总距离、扫视平均距离、正确率等8个指标。被试为12名大学生,刺激材料为10幅中国人脸部图形,主要实验设备是一台Eyelinkll型服动仪。结果发现,显示条件和显示方式对人脸图形识别绩效的影响显著;随着作业难度加大,被试图形识别的首视点注视时间显著增加;人脸图形识别中,显示条件对信息取样注视比率影响显著．而显示方式显著影响信息取样点数量．     

彩色背景下的颜色突显研究

颜色突显是指在与视觉搜索任务有关的视觉显示中,采用颜色突出显示多个项目中的目标项目,从而提高视觉搜索效率的一种方法或技术。本文采用视觉搜索任务,以正确率和反应时为指标对单彩色和复杂彩色背景下不同颜色突显的视觉搜索绩效进行了研究。结果表明：（1）在单彩色背景和复杂彩色背景下,颜色突显条件视觉搜索绩效显著优于非突显条件;（2）在浅蓝或浅绿的单彩色背景下,四种颜色突显绩效中,红色突显绩效最好,紫色最差,而在随机彩色背景和复杂彩色背景下,颜色突显绩效差异并不显著;（3）在彩色背景下的颜色突显绩效会受到干扰数字的颜色的影响,其中在单色和随机彩色背景下,干扰目标颜色为黑色时的视觉搜索绩效优于干扰目标颜色为白色时的情景,而在自然彩色背景下,这种视觉搜索优势并不存在。     

比较视觉搜索任务中工作记忆最小化的眼动研究

采用比较视觉搜索任务和眼动追踪技术,通过增加组成图片的图形数量和改变不同图形的特征属性,考察比较视觉搜索任务是否遵循工作记忆最小化原则以及图形特征加工的优先性问题。结果表明图形数量的增加不影响平均每次注视的图形数量,被试平均每次注视1.65个图形,即比较视觉搜索任务仍遵循工作记忆最小化原则。不同图形中颜色和形状都不同的注视时间最短,颜色不同和形状不同在注视时间上差异不显著,表明比较视觉搜索任务中特征维度数量比特征性质在引导注意上具有优先性。事先不规定搜索路径的情况下,被试主要采用系统搜索策略完成比较搜索任务。     

不同背景下不同频率闪烁的突显工效研究

本实验对黑、白背景下高频、中频、低频三种闪烁的突显工效进行了比较研究。实验结果表明：闪烁作为突显类型可以提高视觉搜索的绩效,而且,在闪烁的频率较高时（２７Ｈｚ以上）,这种闪烁的突显工效更为明显。视觉材料的呈现背景对闪烁突显视觉搜索绩效没有明显的影响,但在白背景下采用闪烁效果较好。     

识图方式与地图难度对定向运动员识图决策绩效与视觉搜索特征的影响

目的：研究旨在探究定向运动员在识别定向运动地图时的决策绩效与视觉搜索特征。方法：研究采用组内设计，操控地图难度（简单和复杂）和运动员识图方式（精确识图和概略识图）对高水平定向运动员进行实验研究。结果：（1）随着地图难度的加大，定向运动员识图准确性下降，概略识图反应时增加。（2）识图时，简单地图比复杂地图注视频率和眼跳距离更大，注视次数更少；概略识图比精确识图注视次数更多、注视频率更高、眼跳距离更大；概略识图时，简单地图条件下运动员从起点开始正向搜索，复杂地图条件下从终点开始逆向搜索，注视区域面积大且分散；精确识图时，无论是简单地图还是复杂地图，所有运动员均首先搜索检查点说明表和终点，注视区域面积小且集中。结论：地图难度制约着定向运动员的识图决策绩效。定向运动员识图的视觉搜索特征受识图方式与地图难度影响，表现出不同的视觉搜索策略。     

眼见为实?视觉搜索的证实反应与策略反应

为检验视觉搜索加工过程中目标驱动与刺激驱动的制约关系,本研究采用视觉搜索范式,操作靶目标颜色与样例颜色是否匹配,以及搜索刺激集的样例颜色比例两个搜索难度变量;并根据靶目标兴趣区注视点情况,把搜索策略划分为证实反应与策略反应。结果表明,在搜索难度增加时,证实反应的比例下降,而策略反应的比例上升,这表明搜索策略的转换优化了注意选择功能。     

汉语发展性阅读障碍儿童的视知觉学习*

研究采用知觉学习经典范式中的视觉搜索任务探讨汉语发展性阅读障碍儿童的知觉学习过程。研究考察了阅读障碍儿童与正常儿童在简单搜索任务、复杂搜索任务和限制时间的复杂搜索任务上的知觉学习特点。结果发现,阅读障碍儿童在复杂搜索任务中初始搜索时间显著长于正常控制组;在限制时间的复杂搜索任务中更进一步发现阅读障碍儿童的反应正确率显著低于正常控制组儿童;而且两组儿童视觉搜索任务的正确率与汉语阅读的识字量成绩存在显著相关。上述结果表明,汉语发展性阅读障碍儿童存在复杂搜索的知觉学习缺陷,这种缺陷可能在某种程度上与儿童的阅读技能发展有关。     

Driving forces in free visual search: An ethology

Visual search typically involves sequences of eye movements under the constraints of a specific scene and specific goals. Visual search has been used as an experimental paradigm to study the interplay of scene salience and top-down goals, as well as various aspects of vision, attention, and memory, usually by introducing a secondary task or by controlling and manipulating the search environment. An ethology is a study of an animal in its natural environment, and here we examine the fixation patterns of the human animal searching a series of challenging illustrated scenes that are well-known in popular culture. The search was free of secondary tasks, probes, and other distractions. Our goal was to describe saccadic behavior, including patterns of fixation duration, saccade amplitude, and angular direction. In particular, we employed both new and established techniques for identifying top-down strategies, any influences of bottom-up image salience, and the midlevel attentional effects of saccadic momentum and inhibition of return. The visual search dynamics that we observed and quantified demonstrate that saccades are not independently generated and incorporate distinct influences from strategy, salience, and attention. Sequential dependencies consistent with inhibition of return also emerged from our analyses.     

Prevalence-based decisions undermine visual search

In visual search, observers make decisions about the presence or absence of a target based on their perception of a target during search. The present study investigated whether decisions can be based on observers’ expectation rather than perception of a target. In Experiment 1, participants were allowed to make target-present responses by clicking on the target or, if the target was not perceived, a target-present button. Participants used the target-present button option more frequently in difficult search trials and when target prevalence was high. Experiment 2 and 3 employed a difficult search task that encouraged the use of prevalence-based decisions. Target presence was reported faster when target prevalence was high, indicating that decisions were, in part, cognitive, and not strictly perceptual. A similar pattern of responses were made even when no targets appeared in the search (Experiment 3). The implication of these prevalence-based decisions for visual search models is discussed.     

比较视觉搜索任务的认知老化研究

本研究通过增加组成图片的图形数量和改变目标图形的特征,考察老年人和大学生在比较视觉搜索任务中的眼动特点和图形特征加工的优先性。结果表明与青年人相比,老年人在比较视觉搜索过程中总注视时间和注视次数增加,平均眼跳幅度减少,对目标刺激的注视时间增加。老年人和青年人在目标刺激的注视过程中都表现出图形维度数量的优先性,即表现为颜色和形状都不同的目标刺激注视时间最短,颜色不同和形状不同的目标刺激在注视时间上差异不显著。说明老年人在比较视觉搜索过程中存在认知老化,在图形特征加工的优先性上结果和青年人一致,以上结果与年龄和研究任务有关。     

Haptic pop-out in a hand sweep

Visually, a red item is easily detected among green items, whereas a mirrored S among normal Ss is not. In visual search, the former is known as the pop-out effect. In daily life, people often also conduct haptic (tactual) searches, for instance, when trying to find keys in their pocket. The aim of the present research was to determine whether there is a haptic version of the pop-out effect. Blindfolded subjects had to search for a target item which differed in roughness from the surrounding distractor items. We report reaction time slopes as low as 20 ms/item. When target and distractor identities were interchanged the slopes increased indicating a search asymmetry. Furthermore, we show that differences in search slope were accompanied by search strategy differences. In some conditions a single-hand sweep over the display was sufficient, while in others a more detailed search strategy was used. By relating haptic search slopes to parallel and serial search strategies we show, for the first time, that pop-out effects occur under free manual exploration.     

Search, enumeration, and aging: eye movement requirements cause age-equivalent performance in enumeration but not in search tasks

Response time (RT) and fixation frequency were measured for young and older adults in search and enumeration tasks under high- and low-attentional competition conditions. There was an age-related decrement in search rates for single targets both for RT and fixation frequency, but there was no deficit in enumeration rates either with or without distractors even though serial enumeration rates were much slower than single target search rates. Fixation frequency per item in serial enumeration was much greater than in serial visual search for a single target. Enumerating targets with distractors produced an overall increase in RT and fixation frequency that was greater for older adults. The data are contrary to a generalized slowing account, and an alternative is proposed on the basis of the need to make eye movements in enumeration but not in search tasks.     

Implications of search accuracy for serial self-terminating models of search

In two experiments, the data from a total of 35 participants was compared to predictions from two competing serial search models, one with perfect memory and one with no memory. Reaction times were collected from an unlimited exposure duration, 4-alternative, target identification search task with array sizes of 8, 12, or 16 items. From the linear function relating RT to number of distractors a hypothetical “inspection time/item” was computed under the assumption of SSTS. Target identification accuracy was obtained from the same participants using the same displays, but with pre- and post-masks used to limit total inspection time (to 120, 180, 300, and 540 ms). Neither the memoryful nor memoryless model provided a good enough fit to the data to support the assumption that serial inspection is the primary process determining search time. Despite direct evidence for serial allocation of attention in visual search, these results suggest that scholars should seriously consider the possibility of hybrid search models in which serial and parallel strategies operate jointly.     

场景情境和目标模板在视觉搜索中的交互作用

以真实场景图像中的物体搜索为实验任务, 操纵场景情境和目标模板, 采用眼动技术将搜索过程分为起始阶段、扫描阶段和确认阶段, 考察场景情境和目标模板对视觉搜索过程的影响机制。结果发现, 场景情境和目标模板的作用方式及时间点不同, 二者交互影响搜索的正确率和反应时, 仅场景情境影响起始阶段的时间, 随后二者交互影响扫描阶段和确认阶段的时间及主要眼动指标。作者由此提出了场景情境和目标模板在视觉搜索中的交互作用模型。