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。     

平滑运动条件下的图形颜色及形状加工特性的研究

本研究对在运动图形识别过程中,有关图形的不同特征（颜色、形状等）的加工特性、方向性效应以及不同空间位置（或时间间隔）对图形识别的影响了探讨。结果发现,视觉系统在运动信息加工时,对目标的不同特征的加工存在不均衡性,加工的难度有差异。颜色的加工难度要比形状的加工难度小。视觉系统对不同运动方向上的图形匹配反应特性也存在差异,图形匹配过程受时间或距离因素的影响,匹配的反应时随着两个比较图形之间的空间距离的增加而减少。     

视野位置及刺激特征对目标搜索影响的眼动研究

在视觉搜索中,注意受多种因素的影响。本研究控制了刺激呈现的3种视野位置,旨在研究在不同视野位置上,各种因素发挥作用的情况。要求被试在4个项目中搜索某一特定的靶子,记录了反应时和多种眼动指标。结果发现,在不同的视野位置上,视觉搜索过程受目标状态和刺激特征的影响程度发生了变化。并且对形状和颜色特征的加工存在时间和加工位置上的差异。     

时-空整合影响图形识别的眼动研究

采用眼动追踪的方法对在不同方向(上、下、左与右)及距离(2.0°‘和4.0°视角)上先后出现的特征组合不同的图形识别过程进行了研究。结果表明。首先,对由不同颜色和形状构成的图形的识别受到图形特征组合的影响,视觉系统对颜色和形状的加工存在明显差异,与颜色加工相比,视觉系统需要更多的时间才能完成形状识别。此外,虽然图形识别的速度和准确性受运动方向与距离的影响较小,但在不同运动方向和距离上,视觉系统是通过改变眼动的时间和空间特性来完成识别任务的,视觉系统在识别过程中的这种时间与空间的整合特点还有待于进一步研究。     

客体和空间工作记忆中三维图形的特征加工时程

采用单探测变化觉察范式，对三维图形的特征在客体和空间工作记忆中的加工时程进行了探讨。实验一的材料是由不同颜色和形状组成的规则立体图形。实验二的材料是由不同颜色和图案组成的六棱柱。实验结果显示：（1）客体和空间工作记忆绩效均随识记项目数的增加而显著下降；（2）随着刺激呈现时间的延长，客体工作记忆绩效显著提高，空间工作记忆绩效无明显增加；且在三种呈现时间条件下，空间工作记忆绩效均高于客体工作记忆；（3）三维图形中颜色特征的检测绩效优于形状、图案和特征捆绑。这些结果表明，视觉工作记忆中三维图形的特征加工存在显著的时程效应，空间位置加工最早完成，其次是颜色加工，然后是形状与颜色-形状的捆绑，最后是图案与颜色-图案的捆绑。     

颜色对基于时间的视觉选择的影响

旨在探讨颜色属性对基于时间的图形预览搜索的影响及其机制。实验采用视觉标记实验范式的变式考察三种颜色的图形刺激的预览收益。结果发现:搜索与旧干扰物相同颜色的靶子和搜索新异颜色刺激并未出现反应时的差异,而且,两者都快于搜索与新干扰物颜色相同的靶子。这说明,在图形刺激的预览搜索中,观察者没有主动抑制旧干扰物的颜色,而是主动加工新出现的刺激。还探讨了基于颜色标记的抑制机制和主动非抑制机制。     

任务难度对自闭症儿童视觉搜索优势显现的影响

探究自闭症谱系障碍(ASD)儿童视觉搜索优势的显现是否受任务难度影响及优势存在机理。本研究采集ASD和正常发育(TD)儿童完成不同难度等级视觉搜索任务的行为和眼动数据。结果发现：在高难度等级任务中ASD组的准确率显著高于TD组;ASD组在任务中对目标刺激的回视次数、对靶子和外周感兴趣区的注视时间显著少于TD组,且ASD组偏好注视刺激的右侧区域。结果表明ASD儿童视觉搜索优势显现受任务难度影响,且可能与其对干扰刺激增强的知觉能力有关。     

视觉客体工作记忆中图形特征存储与捆绑时程

采用单探测变化检测范式,考察了形状和颜色客体在工作记忆中的表征方式、特征检测类型及初始刺激呈现时间对工作记忆表征的影响。结果表明:(1)视觉客体工作记忆的表征包括两个水平,首先是对客体的特征进行加工存储,其次才是对特征的捆绑;(2)不同特征的加工时间不同,颜色的加工完成的较早,记忆效果好,而形状的加工完成的较晚,记忆效果也差,表现出颜色的子系统优势;(3)特征的捆绑不是必需的,只有在任务需要时才进行,并且捆绑的过程符合特征捆绑的双阶段理论。     

词汇视觉复杂性和词频对不同难度汉语搜索阅读的影响

采用眼动记录法,控制词汇视觉复杂性和词频变量,考察词汇视觉特征和语言学特征对汉语搜索阅读的影响。让被试完成简单和复杂搜索任务,结果发现在首次注视时间、凝视时间和跳读率上,复杂性变量主效应显著;词频变量主效应不显著。结果表明:不同任务难度条件下,词汇视觉复杂性影响汉语搜索阅读,词频不影响汉语搜索阅读。汉语搜索阅读对文本的加工可能没有达到词汇语言学水平,而是通过视觉匹配完成搜索阅读。     

三维图形的客体和空间工作记忆存储时程研究

研究采用单探测变化检测范式,探讨了三维图形在视觉客体和空间工作记忆中的存储时程。实验一的三维图形由不同颜色、形状组成,实验二的图形由不同颜色、图案组成。两个实验的结果均发现:被试的正确率随刺激间隔时间的延长而显著下降; 空间工作记忆任务的正确率显著高于客体工作记忆任务。研究结果表明,视觉刺激消失后,不论是客体信息还是空间信息,均随间隔时间的延长而逐渐衰退,且客体信息衰退的速度比空间信息快。总体来看,三维图形的客体和空间信息在视觉工作记忆满负荷条件下能保持大约3～5秒的时间。     

Aging and capacity in the same-different judgment

The same-different judgment was used in two experiments to investigate age-group differences in visual processing. Two targets next to fixation were presented; the targets on one-half of the trials were the same, and on the other half of the trials, the targets differed by color, shape, or color and shape (redundant). Response times were lower for redundant trials than for color-only and shape-only trials; this redundancy gain was greater for older observers than for young observers. Capacity measures based on the integrated hazard functions indicated that young adults, but not older adults, experienced a slowing of processing (reduction of capacity) in the redundant condition. These capacity measures may provide a method for interpreting age-group effects in the presence of overall response-time differences.     

Salience drives overt selection of two equally relevant visual targets

In the present study, we investigated whether salience determines the sequence of selection when participants search for two equally relevant visual targets. To do this, attentional selection was tracked overtly as observers inspected two items of differing physical salience: one a highly salient color singleton, and the other a less salient shape singleton. Participants were instructed to make natural eye movements in order to determine whether two line segments contained within the two singletons were oriented in the same or in different directions. Because both singleton items were task-relevant, participants had no reason to inspect one item before the other. As expected, observers fixated both targets on the majority of trials. Critically, saccades to the color singleton preceded saccades to the less salient shape singleton on the majority of trials. This demonstrates that the order of attentional object selection is largely determined by stimulus salience when task relevance is equated.     

Aging and comparative search for feature differences

In a comparative visual search experiment, two halves of a display contained visual primitives of various shapes and colors. These halves were identical (50% of trials) or contained a non-matching pair (50% of trials). Response time (RT), accuracy, and eye movements were measured in both young and older adults. There were Age Group x Display Size interactions found for RT, with older adult RT affected more than younger adult RT by increases in display size. This interaction was consistent with predictions generated by sequential-sampling models for RT. There were age group main effects on fixation number and fixation duration, but no age group main effects on accuracy, saccade amplitude, or measures of scan-path efficiency; this indicated that search strategies were similar across age groups. Overall, the results showed no special age group deficits for comparative visual search.     

Aging and Comparative Search for Feature Differences

ABSTRACT

In a comparative visual search experiment, two halves of a display contained visual primitives of various shapes and colors. These halves were identical (50% of trials) or contained a non-matching pair (50% of trials). Response time (RT), accuracy, and eye movements were measured in both young and older adults. There were Age Group × Display Size interactions found for RT, with older adult RT affected more than younger adult RT by increases in display size. This interaction was consistent with predictions generated by sequential-sampling models for RT. There were age group main effects on fixation number and fixation duration, but no age group main effects on accuracy, saccade amplitude, or measures of scan-path efficiency; this indicated that search strategies were similar across age groups. Overall, the results showed no special age group deficits for comparative visual search.     

Age differences in the distractor-ratio effect as a function of contrast level

Latencies (RT) and eye movement measures were used to examine the effects of age and contrast on the distractor-ratio effect (DRE) in visual search. Younger and older adults performed a contrast x orientation conjunction search task where the ratios of white to black distractors and luminance contrast levels were varied. The distractor-ratio manipulation had similar effects for older and younger adults on both RT and the number of fixations required to find the target. Both measures were largely independent of distractor ratio on target-present trials, while both RTs and the fixation number increased with the number of items sharing the target's contrast polarity on target-absent trials. A more detailed analysis of eye movements suggested that younger adults were a bit more adept at attending to the smaller set of distractors, which presumably facilitated both overt and covert search. Generalized slowing can account for the age differences in RT, but the fixation number data speak to another mechanism, perhaps increased cautiousness on the part of the elderly when signal strength is low.     

Age Differences in the Distractor-Ratio Effect as a Function of Contrast Level

ABSTRACT

Latencies (RT) and eye movement measures were used to examine the effects of age and contrast on the distractor-ratio effect (DRE) in visual search. Younger and older adults performed a contrast × orientation conjunction search task where the ratios of white to black distractors and luminance contrast levels were varied. The distractor-ratio manipulation had similar effects for older and younger adults on both RT and the number of fixations required to find the target. Both measures were largely independent of distractor ratio on target-present trials, while both RTs and the fixation number increased with the number of items sharing the target's contrast polarity on target-absent trials. A more detailed analysis of eye movements suggested that younger adults were a bit more adept at attending to the smaller set of distractors, which presumably facilitated both overt and covert search. Generalized slowing can account for the age differences in RT, but the fixation number data speak to another mechanism, perhaps increased cautiousness on the part of the elderly when signal strength is low.     

Aging affects the balance between goal-guided and habitual spatial attention

Visual clutter imposes significant challenges to older adults in everyday tasks and often calls on selective processing of relevant information. Previous research has shown that both visual search habits and task goals influence older adults’ allocation of spatial attention, but has not examined the relative impact of these two sources of attention when they compete. To examine how aging affects the balance between goal-driven and habitual attention, and to inform our understanding of different attentional subsystems, we tested young and older adults in an adapted visual search task involving a display laid flat on a desk. To induce habitual attention, unbeknownst to participants, the target was more often placed in one quadrant than in the others. All participants rapidly acquired habitual attention toward the high-probability quadrant. We then informed participants where the high-probability quadrant was and instructed them to search that screen location first—but pitted their habit-based, viewer-centered search against this instruction by requiring participants to change their physical position relative to the desk. Both groups prioritized search in the instructed location, but this effect was stronger in young adults than in older adults. In contrast, age did not influence viewer-centered search habits: the two groups showed similar attentional preference for the visual field where the target was most often found before. Aging disrupted goal-guided but not habitual attention. Product, work, and home design for people of all ages––but especially for older individuals––should take into account the strong viewer-centered nature of habitual attention.     

工作记忆表征捕获眼动中的颜色优先性

刺激属性所具有的引导效力在工作记忆表征自上而下地引导注意捕获过程中起重要作用, 已有研究表明工作记忆表征的颜色属性在引导注意时具有一定的优势。研究采用工作记忆任务与视觉搜索任务相结合的双任务范式, 结合眼动追踪技术, 通过设置具有较强引导效力的颜色属性与朝向属性进行直接竞争的实验条件, 进一步考察工作记忆表征的颜色属性是否依然具有优先性。实验1发现工作记忆表征的颜色属性与朝向属性同时竞争眼动捕获时, 颜色属性表现出较强的优势, 而朝向属性单独呈现时并未表现出任何捕获效应。实验2与3进一步证实了颜色属性捕获眼动的优先性, 即当颜色属性在面临作为靶子属性的朝向属性的竞争时, 依然能捕获更多的注视点。这些结果直接证实了工作记忆表征的颜色属性在工作记忆表征的捕获眼动的过程中具有较强的引导效力, 相对于其他刺激属性(如朝向、形状)更具有优先性。     

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.     

Effects of age on detection of emotional information

Age differences were examined in affective processing, in the context of a visual search task. Young and older adults were faster to detect high arousal images compared with low arousal and neutral items. Younger adults were faster to detect positive high arousal targets compared with other categories. In contrast, older adults exhibited an overall detection advantage for emotional images compared with neutral images. Together, these findings suggest that older adults do not display valence-based effects on affective processing at relatively automatic stages.