Eye movements blink the attentional blink

When presented with a sequence of visual stimuli in rapid succession, participants often fail to detect a second salient target, a phenomenon referred as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992; Shapiro, Raymond, & Arnell, 1997). On the basis of a vast corpus of experiments, several cognitive theories suggest that the blink results from a discrete structuring of attention, sampling information from temporal episodes during which several items can access encoding process (Wyble, Bowman, & Nieuwenstein, 2009; Wyble, Potter, Bowman, & Nieuwenstein, 2011). The objective of this work is to explore the AB when multiple items are presented at the fovea during ocular movements. The authors reasoned that each fixation may cohesively form an episode and hence expected that the blink may vanish within a single fixation. In turn, they expected saccades to accentuate episodic borders and hence shorten the regime of interference when 2 targets are presented fovealy in successive fixations. Evidence is provided in favor of this hypothesis, showing that the blink vanishes when both targets are presented in the core of a single fixation (far from the saccadic boundaries) and that it recovers more rapidly in successive fixations. These studies support current views that episodes should have an effect on the AB and provide evidence that eye movements play an important role in the formation of episodes.     

Scene exploration with Fourier-filtered peripheral information.

In a previous moving-window study it was found that scene exploration benefits more from peripheral information of high spatial frequency than of low spatial frequency. In the present study, degraded versions of realistic scenes were presented peripherally during the initial 150 ms of fixations, while the undegraded scene was presented foveally. The undegraded version of the scene was visible both foveally and peripherally during the later part of fixations. During the initial 150 ms, the peripheral part of scenes was low-pass, bandpass, or high-pass filtered, blanked, or decreased in luminance. In a no-change condition, the undegraded scene was presented throughout the whole fixation. Participants freely explored the scenes in the context of an object-decision task. It was found that degrading peripheral information during the initial part of fixations had minimal effect on scene exploration. No reliable differences were found among the three filter types. The results indicate that, in the context of an object-search task, peripheral information is of minor importance during the initial part of fixations.     

Towards an express-diagnostics for level of processing and hazard perception

The analysis of eye movements can provide rich information about driver's attention and the course of behaviour in hazardous situations. We present data from a driving simulation study showing that the switching between preattentive and attentive processing is reflected in visual fixations. For this initial analysis, we considered fixations from the perspective of their duration and the amplitude of related saccades. Since fixation durations may change instantaneously from one fixation to the next, we further selected the temporal vicinity of the emerging hazard for a closer analysis of fixations around this time. With this second type of analysis, the fixations that actually “detect” a critical event can be discovered and their duration measured. Upon detection of an immediate hazard, there is an increase in fixation duration and a corresponding increase in occurrence of attentive fixations on the cost of preattentive ones. This switching from one level of processing to another is recognisable on a short, phasic time scale. We finally discuss attentional conditions where overlooked or not sufficiently processed hazards do not lead to the appropriate breaking reaction on the part of the driver.     

Information influences the pattern of eye fixations during sentence comprehension

How does the pattern of eye fixation vary as an informative part of a word is encountered? If the processing of information lags behind the movement of the eyes, then we should expect no variation in the pattern; but if processing is immediate, then the movements of the reader's eyes should correspond to the distribution of information being inspected. An experiment is reported which examined the ways that the text ahead of the point of current fixation can be used to guide the eyes to future fixations, by monitoring fixations during a sentence comprehension task. The patterns of eye fixations upon words with uneven distributions of information (where, for example, words predictable from the sight of their first few letters but not from their last few letters are defined as containing informative beginnings) were observed, and it was found that more and longer fixations were produced when subjects looked at the informative parts of words, particularly at the informative endings of words. The results support the suggestion that eye movements are under the moment-to-moment control of cognitive mechanisms.     

不规则几何图形识别取样特征的眼动研究

探讨不规则几何图形识别中取样的眼动特征。被试为12名大学生,刺激材料为20个不规则几何图形,采用EyelinkII型眼动仪。结果发现,随作业难度加大,被试在认知加工中的有效取样时间比显著下降。在不良视觉条件下,图形信息的取样点数量显著减少,眼动扫视路径显著增长。在识别旋转图形时,有效取样时间下降,取样点数量增加,眼动扫视路径增长。图形信息的显示条件与显示方式的交互作用对图形识别的反应时、取样点的数量和眼动扫视路径长度的影响显著。     

Visual scanning during pattern recognition in children and adults

Eye movement and fixation responses of 3- to 6-year-old children and adults were recorded during a pattern recognition task. During familiarization, fixations were more repetitive and less extensive for older subjects. The fixation patterns of older children who were consistently able to solve the recognition problems were like those of the adults. Unsuccessful 4- to 6-year-olds spent more time fixating the modified area of the nonstandard pattern presented in paired comparison with the standard, even though their final decision was false. Thus, preschool children were able to locate relevant visual information even when they did not use this information to solve tasks. The results suggest that visual fixations do not always reflect active attention, and that direct fixations of visual information are clearly not sufficient and may not be necessary for problem solving.     

Fixation durations before word skipping in reading

We resolve a controversy about reading fixations before word-skipping saccades which were reported as longer or shorter than control fixations in earlier studies. Our statistics are based on resampling of matched sets of fixations before skipped and nonskipped words, drawn from a database of 121,321 single fixations contributed by 230 readers of the Potsdam sentence corpus. Matched fixations originated from single-fixation forward-reading patterns and were equated for their positions within words. Fixations before skipped words were shorter before short or high-frequency words and longer before long or low-frequency words in comparison with control fixations. Reasons for inconsistencies in past research and implications for computational models are discussed.     

Areas of Interest as a Signal Detection Problem in Behavioral Eye‐Tracking Research

Decision researchers frequently analyze attention to individual objects to test hypotheses about underlying cognitive processes. Generally, fixations are assigned to objects using a method known as area of interest (AOI). Ideally, an AOI includes all fixations belonging to an object while fixations to other objects are excluded. Unfortunately, due to measurement inaccuracy and insufficient distance between objects, the distributions of fixations to objects may overlap, resulting in a signal detection problem. If the AOI is to include all fixations to an object, it will also likely include fixations belonging to other objects (false positives). In a survey, we find that many researchers report testing multiple AOI sizes when performing analyses, presumably trying to balance the proportion of true and false positive fixations. To test whether AOI size influences the measurement of object attention and conclusions drawn about cognitive processes, we reanalyze four published studies and conduct a fifth tailored to our purpose. We find that in studies in which we expected overlapping fixation distributions, analyses benefited from smaller AOI sizes (0° visual angle margin). In studies where we expected no overlap, analyses benefited from larger AOI sizes (>.5° visual angle margins). We conclude with a guideline for the use of AOIs in behavioral eye‐tracking research. Copyright © 2015 John Wiley & Sons, Ltd.     

The effect of target specification on objects fixated during visual search

When a person searches for a target in a cluttered visual field his eye fixations typically fall on objects. The effect of target specification on the probability of fixating different classes of objects was studied. For fields containing objects differing widely in size, color, and shape: a high proportion of searchers’ fixations were on objects of a specified color, a moderate proportion of their fixations were on objects of a specified size, and a s light proportion of their fixations were on objects of a specified shape. When two or more target characteristics were specified, fixations were generally based on a single characteristic. It is proposed that the specification of a target creates a perceptual structure which the searcher explores. The study of visual fixations, in effect, is the study of the perceptual structure.     

The effect of target specification on objects fixated during visual search

When a person searches for a target in a cluttered visual field his eye fixations typically fall on objects. The effect of target specification on the probability of fixating different classes of objects was studied. For fields containing objects differing Widely in size, color, and shape: a high proportion of searchers’ fixations were on objects of a specified color, a moderate proportion of their fixations were on objects of a specified size, and a slight proportion of their fixations were on objects of a specified shape. When two or more target characteristics were specified, fixations were generally based on a single characteristic. It is proposed that the specification of a target creates a perceptual structure which the searcher explores. The study of visual fixations, in effect, is the study of the perceptual structure.     

Close coupling between eye movements and serial attentional refreshing during multiple-identity tracking

Multiple-identity tracking (MIT) is a dynamic task in which observers track multiple moving objects of distinct identities and then report the location of each target object. The present study examined participant’ eye movements during MIT in order to investigate the relationship between eye movements and attentional performance during the task. The results showed that fixations were predominately directed to individual targets during tracking. When successfully landed on targets, the fixations dwelled for longer duration; otherwise, they were terminated quickly. As the attentional demands for processing the targets increased, fixations landed on the targets more frequently while fixations outside targets decreased both in number and duration. The attentionally more demanding targets were fixated more frequently than the attentionally less demanding ones. The most recently fixated target was tracked with higher performance, while the tracking accuracy for the more previously fixated targets gradually decreased. Taken together, the results indicate that fixations are tightly coupled with attention during MIT, switching serially from target to target for refreshing each object representation to facilitate the tracking of identities and locations of multiple targets.     

A rapid effect of stimulus quality on the durations of individual fixations during reading

We developed a variant of the single fixation replacement paradigm (Yang & McConkie, 2001, 2004) in order to examine the effect of stimulus quality on fixation duration during reading. Subjects' eye movements were monitored while they read passages of text for comprehension. During critical fixations, equal changes to the luminance of the background produced either an increase (Up-Contrast) or a decrease (Down-Contrast) of the contrast of the text. The durations of critical fixations were found to be lengthened in the Down-Contrast but not the Up-Contrast condition. Ex-Gaussian modelling of the distributions of fixation durations showed that the reduction in stimulus quality lengthened the majority of fixations, and a survival analysis estimated the onset of this effect to be approximately 141 ms following fixation onset. Because the stimulus quality of the text during critical fixations could not be predicted or parafoveally previewed prior to foveation, the present effect can be attributed to an immediate effect of stimulus quality on fixation duration.     

藏语阅读中中央凹词频效应及对副中央凹预视效应的影响

在不同语言文字系统中, 对于眼动控制的本质及其发生机制, 尤其是阅读过程中注意资源的分配是序列分布还是平行分布的问题, 目前仍然存在着争论和分歧。藏语是拼音文字, 但它同时又具有汉语的特点, 独具语言特色。因此, 通过对藏语阅读过程中中央凹词频对副中央凹预视效应影响这一问题的探讨, 可以在一种已有研究未曾涉及的文字系统中进一步推动上述争议的解决。本研究采用眼动记录法, 设计了两个实验。实验1操纵了中央凹词频(高频、低频), 考察藏语阅读中中央凹词的词频效应及词频延迟效应, 结果发现, 藏语阅读中存在词频效应及词频延迟效应。实验2同时操纵中央凹词频和副中央凹预视词类型, 借助边界范式, 考察藏语阅读中副中央凹预视效应及中央凹词频对副中央凹预视效应的影响, 结果发现, 藏语阅读中存在副中央凹预视效应, 且与低频中央凹词相比, 高频中央凹词对副中央凹预视效应的促进作用更大。两个实验结果表明:(1)藏语阅读中存在显著的词频效应, 且表现在词汇加工的整个过程; (2)藏语阅读中存在显著的词频延迟效应, 并贯穿于词汇加工的整个过程; (3)藏语阅读中存在显著的副中央凹预视效应, 读者能通过副中央凹预视提取到语音和字形信息。藏语阅读中中央凹词频影响副中央凹预视效应的大小, 且词频只在词汇加工的早期对形的预视信息的提取产生影响, 即在形似预视条件下高频词的预视效应更大; (4)本研究发现的词频延迟效应及副中央凹预视效应, 支持了E-Z读者模型中有关副中央凹序列加工的观点。     

Perception of object-context relations: eye-movement analyses in infants and adults

Twenty-eight 4-month-olds' and twenty-two 20-year-olds' attention to object-context relations was investigated using a common eye-movement paradigm. Infants and adults scanned both objects and contexts. Infants showed equivalent preferences for animals and vehicles and for congruent and incongruent object-context relations overall, more fixations of objects in congruent object-context relations, more fixations of contexts in incongruent object-context relations, more fixations of objects than contexts in vehicle scenes, and more fixation shifts in incongruent than congruent vehicle scenes. Adults showed more fixations of congruent than incongruent scenes, vehicles than animals, and objects than contexts; equal fixations of animals and their contexts but more fixations of vehicles than their contexts; and more shifts of fixation when inspecting animals in context than vehicles in context. These findings for location, number, and order of eye movements indicate that object-context relations play a dynamic role in the development and allocation of attention.     

Binocular masking induced by a moving object

Movement in a part of either of two binocular fields can, under some conditions, produce temporary obliteration of the corresponding part of the other field. This paper is a mainly qualitative study of this rather surprising phenomenon. The effect is found to increase from the fovea to the periphery, to be greatest at a velocity of about 20° visual angle per sec. and to vary with the orientation of the fixation point in the visual field. Some further lines of research designed to elucidate the relation of the effect described here to certain other visual phenomena are suggested.     

Effects of viewing time,fixations, and viewing strategies on visual memory for briefly presented natural objects

We investigated the impact of viewing time and fixations on visual memory for briefly presented natural objects. Participants saw a display of eight natural objects arranged in a circle and used a partial report procedure to assign one object to the position it previously occupied during stimulus presentation. At the longest viewing time of 7,000 ms or 10 fixations, memory performance was significantly higher than at the shorter times. This increase was accompanied by a primacy effect, suggesting a contribution of another memory component—for example, visual long-term memory (VLTM). We found a very limited beneficial effect of fixations on objects; fixated objects were only remembered better at the shortest viewing times. Our results revealed an intriguing difference between the use of a blocked versus an interleaved experimental design. When trial length was predictable, in the blocked design, target fixation durations increased with longer viewing times. When trial length was unpredictable, fixation durations stayed the same for all viewing lengths. Memory performance was not affected by this design manipulation, thus also supporting the idea that the number and duration of fixations are not closely coupled to memory performance.     

Eye movements during scene viewing: Evidence for mixed control of fixation durations

Recent behavioral and computational research on eye movement control during scene viewing has focused on where the eyes move. However, fixations also differ in their durations, and when the eyes move may be another important indicator of perceptual and cognitive activity. Here we used a scene onset delay paradigm to investigate the degree to which individual fixation durations are under direct moment-to-moment control of the viewer’s current visual scene. During saccades just prior to critical fixations, the scene was removed from view so that when the eyes landed, no scene was present. Following a manipulated delay period, the scene was restored to view. We found that one population of fixations was under the direct control of the current scene, increasing in duration as delay increased. A second population of fixations was relatively constant across delay. The pattern of data did not change whether delay duration was random or blocked, suggesting that the effects were not under the strategic control of the viewer. The results support a mixed control model in which the durations of some fixations proceed regardless of scene presence, whereas others are under the direct moment-to-moment control of ongoing scene analysis.     

高中二年级学生中文阅读知觉广度的眼动研究

采用“呈现随眼动变化技术”对高中二年级学生中文阅读的知觉广度进行了眼动研究。结果发现,高中二年级学生的阅读知觉广度具有不对称性,大约为注视点左侧一个或两个汉字到注视点右侧三个或四个汉字的空间;高中二年级学生在正常阅读中的眼跳距离约为三个汉字的空间,在连续注视的过程中知觉广度有较小范围的重叠。     

发展性阅读障碍与知觉加工

近年来许多行为实验和神经生理学实验都发现 ,发展性阅读障碍与基本知觉障碍有关。在视觉领域研究者提出了巨细胞障碍假设 ,这种假设认为阅读障碍者视觉神经系统中的巨细胞障碍导致他们对某种类型的视觉刺激加工存在困难 ,进而影响阅读。在听觉领域研究发现阅读障碍者加工快速、系列、短暂呈现的声音刺激存在障碍。研究者认为阅读障碍者加工快速刺激输入障碍反映了普遍的时间知觉障碍。这方面的研究发展非常迅速 ,理论观点非常明确 ,并且直接与内在的神经机制相联系 ,形成了与传统的“语言障碍”理论迥然不同的“知觉障碍”理论。“知觉障碍”理论综合了行为、认知和神经等多个层次的研究 ,反映了神经科学发展所带来的巨大影响和认知加工模块化理论的渐渐衰退。