Does working memory capacity predict cross-modally induced failures of awareness?

People often fail to notice unexpected stimuli when they are focusing attention on another task. Most studies of this phenomenon address visual failures induced by visual attention tasks (inattentional blindness). Yet, such failures also occur within audition (inattentional deafness), and people can even miss unexpected events in one sensory modality when focusing attention on tasks in another modality. Such cross-modal failures are revealing because they suggest the existence of a common, central resource limitation. And, such central limits might be predicted from individual differences in cognitive capacity. We replicated earlier evidence, establishing substantial rates of inattentional deafness during a visual task and inattentional blindness during an auditory task. However, neither individual working memory capacity nor the ability to perform the primary task predicted noticing in either modality. Thus, individual differences in cognitive capacity did not predict failures of awareness even though the failures presumably resulted from central resource limitations.     

Effects of canonical color,luminance, and orientation on sustained inattentional blindness for scenes

Whether scene gist perception occurs automatically and unconsciously has been the subject of much debate. In addition to demonstrating a new method that adapts the Mack and Rock (1998) inattentional blindness cross procedure to allow for sustained inattentional blindness over a large number of trials, we report evidence from a series of experiments that shows that canonical scene features reduce inattentional blindness to scenes by facilitating the extraction of scene gist. When attentional demands are high, the combination of canonical color, canonical luminance, and canonical orientation reduces rates of inattentional blindness. However, when attentional demands are reduced, canonical features are independently sufficient to facilitate gist extraction and to capture attention. These results demonstrate that canonical color, canonical luminance, and canonical orientation all contribute to scene gist perception, and that when attentional demands are high, only highly canonical stimuli are sufficient to capture attention.     

刺激类型及表征关系对无意视盲的影响

通过考察刺激类型以及重叠呈现的图片流和词语流的表征关系对非注意刺激的捕获差异,试图考察刺激类型和表征关系对无意视盲（Inattentional Blindness）的影响。分别有20名中学生参加了词和图片基线水平测试,52名中学生参与了无意视盲实验。研究结果表明：（1）当词与图片重叠呈现时,不管注意刺激是词还是图片,也不管词与图片的表征是否一致,与基线水平相比,被试都出现了显著的无意视盲现象。（2）当词与图片的表征意义一致时,如果注意刺激是图片,而非注意刺激是词,那么被试更容易觉察到非注意刺激。（3）非注意刺激与注意刺激表征意义一致时更容易捕获观察者的注意     

The relationship between fluid intelligence and sustained inattentional blindness in 7-to-14-year-old children

Previous researches have shown that people with higher fluid intelligence are more likely to detect the unexpected stimuli. The current study systematically explored the relationship between fluid intelligence and sustained inattentional blindness in children. In Experiment 1, we measured one hundred and seventy-nine 7-to-14-year-old children’s fluid intelligence and sustained inattentional blindness. The results showed that fluid intelligence was negatively related to sustained inattentional blindness only in 7-to-8-year-old children. In Experiment 2, we explored sustained inattentional blindness in sixty children with high Raven’s scores. We found that compared with children who have average Raven’s scores aged 11-to-12 years old, children with high Raven’s scores were unable to better avoid sustained inattentional blindness. In general, this research implies that the relation between fluid intelligence and sustained inattentional blindness is weak. Fluid intelligence could predict sustained inattentional blindness only when children do not have enough perceptual capacities to complete the primary task.     

Attentional inhibition mediates inattentional blindness

Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle (the critical stimulus) was concurrently presented. Participants were instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location (at the same eccentricity). In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy.     

Perception in the absence of attention: perceptual processing in the Roelofs effect during inattentional blindness

We present two experiments that examine sensory processing during conditions of inattentional blindness. A large rectangular frame that normally induces a Roelofs effect can go unreported due to inattentional blindness. Even when participants fail to report the frame, they mislocalize an attended target in a way consistent with having processed the frame. A more demanding visuospatial distractor task can increase inattentional blindness during conditions of divided attention, but has no effect on the spatial mislocalization illusion. Our results support theories that postulate a significant amount of perceptual processing in the absence of attention.     

Do people with autistic spectrum disorder show normal selection for attention? Evidence from change blindness

People in the general population are typically very poor at detecting changes in pictures of complex scenes. The degree of this ‘change blindness’, however, varies with the content of the scene: when an object is semantically important or contextually inappropriate, people may be more effective at detecting changes. Two experiments investigated change blindness in people with autism, who are known from previous research to be efficient in detecting features yet poor at processing stimuli for meaning and context. The first experiment measured the effect of semantic information while the second investigated the role of context in directing attention. In each task, participants detected the dissimilarity between pairs of images. Both groups showed a main effect of image type in both experimental tasks, showing that their attention was directed to semantically meaningful and contextually inappropriate items. However, the autistic group also showed a greater difficulty detecting changes to semantically marginal items in the first experiment. Conclusions point to a normal selection of items for attention in people with autism spectrum disorders, although this may be combined with difficulty switching or disengaging attention.     

Distance is relative: Inattentional blindness critically depends on the breadth of the attentional focus

Inattentional blindness – the phenomenon that we sometimes miss salient stimuli in our direct view when they appear unexpectedly and attention is focused on something else - is modulated by various parameters, including distance of the unexpected stimulus from the attentional focus. In two experiments, we expanded the existing literature on spatial factors influencing inattentional blindness as well as theories on the spatial distribution of attention. Noticing rates of unexpected objects were significantly higher when they appeared outside instead of inside the bounds of primary task stimuli. Thus, our results do neither support the account that spatial attention is tuned as a spotlight that includes relevant targets and everything in between nor an account of purely object-based attentional orientation. Instead, the results speak in favor of an inhibitory area between two attended targets. Experiment 2 replicated these surprising findings and additionally demonstrated that they were not confounded by task.     

Animacy,perceptual load,and inattentional blindness

Inattentional blindness is the failure to notice unexpected objects in a visual scene while engaging in an attention-demanding task. We examined the effects of animacy and perceptual load on inattentional blindness. Participants searched for a category exemplar under low or high perceptual load. On the last trial, the participants were exposed to an unexpected object that was either animate or inanimate. Unexpected objects were detected more frequently when they were animate rather than inanimate, and more frequently with low than with high perceptual loads. We also measured working memory capacity and found that it predicted the detection of unexpected objects, but only with high perceptual loads. The results are consistent with the animate-monitoring hypothesis, which suggests that animate objects capture attention because of the importance of the detection of animate objects in ancestral hunter–gatherer environments.     

Attentional selection is biased toward mood-congruent stimuli

One can exert significant volitional control over the attentional filter so that stimuli that are consistent with one's explicit goals are more likely to receive attention and become part of one's conscious experience. Here we pair a mood induction procedure with an inattentional blindness task to show that one's current mood has a similar influence on attention. A positive, negative, or neutral mood manipulation was followed by an attentionally demanding multiple-object tracking task. During the tracking task, participants were more likely to notice an unexpected face when its emotional expression was congruent with participants' mood. This was particularly true for the frowning face, which was detected almost exclusively by participants in the sad mood induction condition. This attentional bias toward mood-congruent stimuli provides evidence that one's temporary mood can influence the attentional filter, thereby affecting the information that one extracts from, and how one experiences the world.     

What we see: inattention and the capture of attention by meaning

Attention is necessary for the conscious perception of any object. Objects not attended to are not seen. What is it that captures attention when we are engaged in some attention-absorbing task? Earlier research has shown that there are only a very few stimuli which have this power and therefore are reliably detected under these conditions (for example, Mack & Rock, 1998; Moray, 1959). The two most reliable are the observer's own name and a happy face icon which seem to capture attention by virtue of their meaning. Three experiments are described which explore whether these stimuli are detected under conditions, heretofore unexamined, which either cause inattentional blindness or are associated with a perceptual failure associated with the limits of attention. The evidence obtained indicates that these stimuli have a unique capacity to capture and extend the limits of attention under conditions in which this has been deemed highly unlikely.     

Not All Hazards are Created Equal: The Significance of Hazards in Inattentional Blindness for Static Driving Scenes

Explaining how we attend to some objects and not others in real world environments remains a challenge for theories of attention. Driving is an ideal example of this, as it requires a complex synthesis of attentional processing, while still allowing attention to be captured by hazards. In the current study we employed a static inattentional blindness (IB) driving task in which participants were required to make decisions about the content of driving‐related scenarios. In a critical trial, an additional stimulus was added to the driving scenario. All unexpected stimuli were thematically consistent with a normal driving environment but varied in their level of hazard threat. Rates of IB were consistent with the level of hazard threat of the stimuli. The results are discussed in terms of semantic‐based attentional capture in driving, and models of IB.Copyright © 2015 John Wiley & Sons, Ltd.     

Executive working memory load induces inattentional blindness

When attention is engaged in a task, unexpected events in the visual scene may go undetected, a phenomenon known as inattentional blindness (IB). At what stage of information processing must attention be engaged for IB to occur? Although manipulations that tax visuospatial attention can induce IB, the evidence is more equivocal for tasks that engage attention at late, central stages of information processing. Here, we tested whether IB can be specifically induced by central executive processes. An unexpected visual stimulus was presented during the retention interval of a working memory task that involved either simply maintaining verbal material or rearranging the material into alphabetical order. The unexpected stimulus was more likely to be missed during manipulation than during simple maintenance of the verbal information. Thus, the engagement of executive processes impairs the ability to detect unexpected, task-irrelevant stimuli, suggesting that IB can result from central, amodal stages of processing.     

Individual differences in susceptibility to inattentional blindness

Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by variability in working memory capacity, modulate susceptibility to inattentional blindness. Participants watched a classic inattentional blindness video (Simons & Chabris, 1999) and were instructed to count passes among basketball players, wherein 58% noticed the unexpected: a person wearing a gorilla suit. When participants were accurate with their pass counts, individuals with higher working memory capacity were more likely to report seeing the gorilla (67%) than those with lesser working memory capacity (36%). These results suggest that variability in attentional control is a potential mechanism underlying the apparent modulation of inattentional blindness across individuals.     

Out of Mind, Out of Sight: Unexpected Scene Elements Frequently Go Unnoticed Until Primed

The human visual system employs a sophisticated set of strategies for scanning the environment and directing attention to stimuli that can be expected given the context and a person’s past experience. Although these strategies enable us to navigate a very complex physical and social environment, they can also cause highly salient, but unexpected stimuli to go completely unnoticed. To examine the generality of this phenomenon, we conducted eight studies that included 15 different experimental conditions and 1,577 participants in all. These studies revealed that a large majority of participants do not report having seen a woman in the center of an urban scene who was photographed in midair as she was committing suicide. Despite seeing the scene repeatedly, 46 % of all participants failed to report seeing a central figure and only 4.8 % reported seeing a falling person. Frequency of noticing the suicidal woman was highest for participants who read a narrative priming story that increased the extent to which she was schematically congruent with the scene. In contrast to this robust effect of inattentional blindness, a majority of participants reported seeing other peripheral objects in the visual scene that were equally difficult to detect, yet more consistent with the scene. Follow-up qualitative analyses revealed that participants reported seeing many elements that were not actually present, but which could have been expected given the overall context of the scene. Together, these findings demonstrate the robustness of inattentional blindness and highlight the specificity with which different visual primes may increase noticing behavior.     

ERP signatures of conscious and unconscious word and letter perception in an inattentional blindness paradigm

A three-phase inattentional blindness paradigm was combined with ERPs. While participants performed a distracter task, line segments in the background formed words or consonant-strings. Nearly half of the participants failed to notice these word-forms and were deemed inattentionally blind. All participants noticed the word-forms in phase 2 of the experiment while they performed the same distracter task. In the final phase, participants performed a task on the word-forms. In all phases, including during inattentional blindness, word-forms elicited distinct ERPs during early latencies (∼200–280 ms) suggesting unconscious orthographic processing. A subsequent ERP (∼320–380 ms) similar to the visual awareness negativity appeared only when subjects were aware of the word-forms, regardless of the task. Finally, word-forms elicited a P3b (∼400–550 ms) only when these stimuli were task-relevant. These results are consistent with previous inattentional blindness studies and help distinguish brain activity associated with pre- and post-perceptual processing from correlates of conscious perception.     

非预想刺激的运动速率对无意视盲的影响

无意视盲是指由于对某些事物的专注而导致的眼前对象被忽视的现象。它受到诸如非预想刺激的位置、大小、颜色; 非预想刺激与注意刺激之间的关系; 被试的年龄、专业知识、加工能力等诸多因素的影响。本文通过改进的MR范式考察了“等时”和“等距”条件下非预想刺激的运动速率对无意视盲的影响。实验结果显示: (1)非预想刺激的运动速率和其呈现时间对无意视盲的比率有显著影响; (2)在一定的呈现时间范围内, 视盲率随运动速率的升高而降低, 但当维持相等的运动距离时, 视盲率没有显著变化; (3)当呈现时间超出一定范围时, 运动速率对无意视盲的影响急剧减小, 即呈现时间制约着运动速率对无意视盲的影响, 两者间呈倒U型曲线关系。文末就实验结果进行了详细分析和讨论。     

Working memory and inattentional blindness

Individual differences in working memory predict many aspects of cognitive performance, especially for tasks that demand focused attention. One negative consequence of focused attention is inattentional blindness, the failure to notice unexpected objects when attention is engaged elsewhere. Yet, the relationship between individual differences in working memory and inattentional blindness is unclear; some studies have found that higher working memory capacity is associated with greater noticing, but others have found no direct association. Given the theoretical and practical significance of such individual differences, more definitive tests are needed. In two studies with large samples, we tested the relationship between multiple working memory measures and inattentional blindness. Individual differences in working memory predicted the ability to perform an attention-demanding tracking task, but did not predict the likelihood of noticing an unexpected object present during the task. We discuss the reasons why we might not expect such individual differences in noticing and why other studies may have found them.     

Natural-scene perception requires attention

Is visual attention required for visual consciousness? In the past decade, many researchers have claimed that awareness can arise in the absence of attention. This claim is largely based on the notion that natural scene (or "gist") perception occurs without attention. This article presents evidence against this idea. We show that when observers perform a variety of demanding, sustained-attention tasks, inattentional blindness occurs for natural scenes. In addition, scene perception is impaired under dual-task conditions, but only when the primary task is sufficiently demanding. This finding suggests that previous studies that have been interpreted as demonstrating scene perception without attention failed to fully engage attention and that natural-scene perception does indeed require attention. Thus, natural-scene perception is not a preattentive process and cannot be used to support the idea of awareness without attention.     

意外刺激的意义性及位置对大学生无意视盲的影响

无意视盲是指由于专注于某项任务而对视野中的其他事物视而不见的现象,它同时受意外刺激低水平的物理特性、语义相关性以及观察者自身因素的影响。无意视盲是联系知觉、意识和注意的重要桥梁。本文采用静态的无意视盲范式,随机选取80名在校大学生为被试,同时考察了意外刺激的位置和意义性对无意视盲的影响。结果表明:(1)意外刺激的呈现位置对无意视盲没有显著的影响,呈现在外周和中央的探测率无显著差异。说明无意视盲可能是受基于注意区域而不是基于注视点的位置因素的影响;(2)意外刺激的意义性对无意视盲有显著的影响,相比于无意义刺激,有意义的卡通笑脸不管呈现在中央还是外周,都更易获得探测。