Aging increases inattentional blindness to the gorilla in our midst

When engaged in an attention-demanding task, people are surprisingly vulnerable to inattentional blindness--the failure to notice an unexpected event. Two theories of cognitive aging, attentional capacity models and inhibitory deficit models, make opposite predictions about age differences in susceptibility to inattentional blindness. We tested these predictions using an inattentional blindness paradigm developed by Simons and Chabris (1999) and found that older adults were more likely to experience inattentional blindness than young adults. These results are compatible with attentional capacity models of cognitive aging but not with current inhibitory deficit models.     

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.     

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.     

Individual differences in working memory capacity predict action monitoring and the error-related negativity

Neuroscience suggests that the anterior cingulate cortex (ACC) is responsible for conflict monitoring and the detection of errors in cognitive tasks, thereby contributing to the implementation of attentional control. Though individual differences in frontally mediated goal maintenance have clearly been shown to influence outward behavior in interference-rich contexts, it is unclear whether corresponding differences exist in neural responses that arise out of the ACC. To investigate this possibility, we conducted an electrophysiological study using a variant of the Simon Task, recording event-related potentials (ERPs) in healthy normal individuals with varying working memory capacity (high vs. low spans; a behavioral proxy for variability in goal maintenance). Primary analyses focused on the magnitude of the error-related negativity (ERN), a response-locked ERP component associated with the commission of errors thought to arise because of action monitoring in the ACC. Our results revealed that frontally mediated working memory capacity may alter error monitoring by the ACC, with high spans showing a greater ERN than low spans. These individual differences were also observed in the posterror positivity, a response-locked ERP component associated with updating cognitive strategies, suggesting greater awareness of errors with increased working memory capacity. These results are interpreted within 2-process models of attentional control, suggesting individuals with greater working memory capacity may better maintain task goals by more strongly biasing neural activity in frontal-executive networks.     

Release of inattentional blindness by high working memory load: elucidating the relationship between working memory and selective attention

An unexpected stimulus often remains unnoticed if attention is focused elsewhere. This inattentional blindness has been shown to be increased under conditions of high memory load. Here we show that increasing working memory load can also have the opposite effect of reducing inattentional blindness (i.e., improving stimulus detection) if stimulus detection is competing for attention with a concurrent visual task. Participants were required to judge which of two lines was the longer while holding in working memory either one digit (low load) or six digits (high load). An unexpected visual stimulus was presented once alongside the line judgment task. Detection of the unexpected stimulus was significantly improved under conditions of higher working memory load. This improvement in performance prompts the striking conclusion that an effect of cognitive load is to increase attentional spread, thereby enhancing our ability to detect perceptual stimuli to which we would normally be inattentionally blind under less taxing cognitive conditions. We discuss the implications of these findings for our understanding of the relationship between working memory and selective attention.     

注意捕获的另一扇窗户——无意视盲

观察者集中注意于某个物体或事件的时候,他们经常不能觉察到显著的、与众不同的物体,这种现象被称为“无意视盲”（Inattentional Blindness）。在无意视盲研究中,存在两类实验范式——静态无意视盲和动态无意视盲研究范式。首先,从刺激的感觉显著性、认知显著性、心理工作负荷、定势和期望以及加工能力等方面分析了影响无意视盲的因素;其次,对无意视盲和无意遗忘的争议以及无意视盲是“全或无”还是连续谱的争议也进行了总结;最后,从无意视盲角度出发探讨了内隐注意捕获和外显注意捕获之间的关系     

The effects of individual differences and task difficulty on inattentional blindness

Most studies of inattentional blindness—the failure to notice an unexpected object when attention is focused elsewhere—have focused on one critical trial. For that trial, noticing the unexpected object might be a result of random variability, so that any given individual would be equally likely to notice the unexpected object. On the other hand, individual differences in the ability to perform the primary task might make noticing more likely for some individuals than for others. Increasing the difficulty of the primary task has been shown to decrease noticing rates for both brief static displays (Cartwright-Finch & Lavie, 2007) and dynamic monitoring tasks (Simons & Chabris, 1999). However, those studies did not explore whether individual differences in noticing arise from differences in the ability to perform the primary task. For our Experiment 1, we used a staircase procedure to equate primary task performance across individuals in a dynamic inattentional blindness task and found that the demands of the primary task affected noticing rates when individual differences in accuracy were minimized. In Experiment 2, we found that individual differences in primary task performance did not predict noticing of an unexpected object. Together, these findings suggest that although the demands of the primary task do affect inattentional blindness rates, individual differences in the ability to meet those demands do not.     

What’s “inattentional” about inattentional blindness?

In a recent commentary, Memmert critiqued claims that attentional misdirection is directly analogous to inattentional blindness (IB) and cautioned against assuming too close a similarity between the two phenomena. One important difference highlighted in his analysis is that most lab-based inductions of IB rely on the taxing of attention through a demanding primary task, whereas attentional misdirection typically involves simply the orchestration of spatial attention. The present commentary argues that, rather than reflecting a complete dissociation between IB and attentional misdirection, this difference highlights potential grounds for delineating mechanistically distinct forms of IB: spatial inattentional blindness, which stems from the covert misallocation of spatial attention, and central inattentional blindness, which stems from disruption or preoccupation of perceptual mechanisms that interface with higher-level processes such as working memory. Recognition of such distinctions can help situate theoretical understanding of IB more firmly within the context of the broader attention literature.     

Concepts about agency constrain beliefs about visual experience

Recent research exploring phenomena such as change blindness, inattentional blindness, attentional blink and repetition blindness has revealed a number of counterintuitive ways in which apparently salient visual stimuli often go unnoticed. In fact, large majorities of subjects sometimes predict that they would detect visual changes that actually are rarely noticed, suggesting that people have strong beliefs about visual experience that are demonstrably incorrect. However, for other kinds of visual metacognition, such as picture memory, people underpredict performance. This paper describes two experiments demonstrating that both these overpredictions of change detection, and underpredictions of visual memory can be linked with intuitions about the visual experience of different kinds of agents. Subjects predicted more visual change detection and poorer visual memory for mechanical representational systems (e.g. computer programs) when these were anthropomorphized using intentional terminology.     

Dynamic search and working memory in social recall

What are the mechanisms underlying search in social memory (e.g., remembering the people one knows)? Do the search mechanisms involve dynamic local-to-global transitions similar to semantic search, and are these transitions governed by the general control of attention, associated with working memory span? To find out, we asked participants to recall individuals from their personal social networks and measured each participant's working memory capacity. Additionally, participants provided social-category and contact-frequency information about the recalled individuals as well as information about the social proximity among the recalled individuals. On the basis of these data, we tested various computational models of memory search regarding their ability to account for the patterns in which participants recalled from social memory. Although recall patterns showed clustering based on social categories, models assuming dynamic transitions between representations cued by social proximity and frequency information predicted participants' recall patterns best-no additional explanatory power was gained from social-category information. Moreover, individual differences in the time between transitions were positively correlated with differences in working memory capacity. These results highlight the role of social proximity in structuring social memory and elucidate the role of working memory for maintaining search criteria during search within that structure.     

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.     

Mind the gap: Misdirection, inattentional blindness and the relationship between overt and covert attention

The present commentary addresses two issues arising from Memmert’s (2010) paper. First, can the ‘misdirection’ and ‘inattentional blindness’ paradigms provide important insights into the relationship between ‘overt’ and ‘covert’ attentional processes? Second, what are the most fruitful directions for research that seeks to combine these attentional paradigms in ecologically valid settings? We argue that although Memmert’s (2010) paper postulates several important differences between the misdirection and inattentional blindness paradigms, it may not emphasise sufficiently strongly the significant insights into attention that have been yielded by the former approach. To illustrate, we discuss the utility of the misdirection paradigm in providing an ecologically valid method to investigate the relationship between overt and covert attentional processes. Such naturalistic methods are required to ensure optimal integration of the misdirection and inattentional blindness paradigms within a general theory of attention.     

The gap between inattentional blindness and attentional misdirection

Kuhn and colleagues described a novel attentional misdirection approach (deliberate diversion of attention away from a visually salient stimulus) to investigate overt and covert attention mechanisms in connection with inattentional blindness (not being able to perceive something that is plainly visible because one’s attention has not been focused on it). This misdirection paradigm is valuable to study the temporal relationship between eye movements and visual awareness. Although, as put forth in this comment, the link between attentional misdirection and inattentional blindness needs to be developed further. There are at least four differences between the two paradigms which concern the conceptual aspects of the unexpected object and the methodological aspects of the task design. This highlights the need for a broader theoretical framework incorporating inattentional blindness and overt and covert attention mechanisms. Two possible research lines focusing on the orienting attention research and the “selection-for-action” paradigm are discussed.     

Under High Perceptual Load,Observers Look but Do Not See

High perceptual load reduces distractor processing and increases inattentional blindness for unexpected stimuli. We reported previously that high perceptual load reduces memory accuracy and impairs eyewitness identification. Here, we used eye tracking to investigate whether memory impairments under load are due to inattentional blindness or a failure to visually inspect stimuli. Seventy‐two participants viewed high or low load versions of a video depicting a theft and identified characters in the video from photographic line‐ups. High perceptual load impaired participants' ability to identify the peripheral character (witness) but not the central character (thief). There was no effect of perceptual load on number of ocular fixations on the witness, time to first fixation or total visit duration. We conclude that memory impairments under load are due to attentional failures rather than differences in visual search behaviour. These findings suggest that high perceptual load scenes may hamper eyewitnesses' ability to encode easily visible stimuli. Copyright © 2017 John Wiley & Sons, Ltd.     

Aging and the role of working memory resources in visuospatial attention

Visuospatial attention has been shown to be robust to the effects of increasing age. Nonetheless, models linking individual differences in working memory capacity to attentional performance suggest that older adults may experience disruptions in visuospatial attention under conditions of resource load. Two experiments were conducted to investigate the effects of age and concurrent working memory load on two tasks that have been proposed to require posterior attentional processes. The findings suggest that loading working memory resources selectively disrupts performance on a nonintegrated Stroop task, whereas cue utilization remains intact. In addition, imposing a working memory load delays the deployment of visuospatial attention in both experiments. Regarding the effects of age, findings suggest that older adults can effectively perform both attentional tasks despite working memory load. Age differences did emerge in the time course of cue utilization. Findings point to the resilience of visuospatial attention in aging, even under conditions of significant cognitive load. We discuss these results and their implications for models postulating a role for working memory capacity in attentional behaviors.     

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     

Attentional blink magnitude is predicted by the ability to keep irrelevant material out of working memory

Participants have difficulty in reporting the second of two masked targets if the second target is presented within 500 ms of the first target—an attentional blink (AB). Individual participants differ in the magnitude of their AB. The present study employed an individual differences design and two visual working memory tasks to examine whether visual working memory capacity and/or the ability to exclude irrelevant information from visual working memory (working memory filtering efficiency) could predict individual differences in the AB. Visual working memory capacity was positively related to filtering efficiency, but did not predict AB magnitude. However, the degree to which irrelevant stimuli were admitted into visual working memory (i.e., poor filtering efficiency) was positively correlated with AB magnitude over and above visual working memory capacity. Good filtering efficiency may benefit the AB by not allowing irrelevant RSVP distractors to gain access to working memory.     

Sources of individual differences in working memory: Contributions of strategy to capacity

Some research on attentional control in working memory has emphasized theoretical capacity differences. However, strategic behavior, which has been relatively unexplored, can also influence attentional control and its relationship to cognitive performance. In two experiments, we examined the relationship between attentional control (measured with operation span) and interference in a part-list cuing paradigm. Paradoxically, the results indicated that superior attentional control was related to increased interference. This relationship reflected the participants’ use of more complex encoding strategies, rather than superior interference control at retrieval, and was eliminated following brief encoding strategy training. The results suggest that complex span measures sometimes predict individual differences in task strategies related to interference control and that these strategies may be amenable to training. The implications for working memory research and the roles of strategies in basic memory and attention paradigms are briefly discussed.     

How not to be seen: the contribution of similarity and selective ignoring to sustained inattentional blindness

When people attend to objects or events in a visual display, they often fail to notice an additional, unexpected, but fully visible object or event in the same display. This phenomenon is now known as inattentional blindness . We present a new approach to the study of sustained inattentional blindness for dynamic events in order to explore the roles of similarity, distinctiveness, and attentional set in the detection of unexpected objects. In Experiment 1, we found that the similarity of an unexpected object to other objects in the display influences attentional capture: The more similar an unexpected object is to the attended items, and the greater its difference from the ignored items, the more likely it is that people will notice it. Experiment 2 explored whether this effect of similarity is driven by selective ignoring of irrelevant items or by selective focusing on attended items. The results of Experiment 3 suggest that the distinctiveness of the unexpected object alone cannot entirely account for the similarity effects found in the first two experiments; when attending to black items or white items in a dynamic display, nearly 30% of observers failed to notice a bright red cross move across the display, even though it had a unique color, luminance, shape, and motion trajectory and was visible for 5 s. Together, the results suggest that inattentional blindness for ongoing dynamic events depends both on the similarity of the unexpected object to the other objects in the display and on the observer's attentional set.     

Attentional responses on an auditory oddball predict false memory susceptibility

Attention and memory are highly integrated processes. Building on prior behavioral investigations, this study assesses the link between individual differences in low-level neural attentional responding and false memory susceptibility on the misinformation effect, a paradigm in which false event memories are induced via misleading post-event information. Twenty-four subjects completed the misinformation effect paradigm after which high-density (256-channel) EEG data was collected as they engaged in an auditory oddball task. Temporal-spatial decomposition was used to extract two attention-related components from the oddball data, the P3b and Classic Slow Wave. The P3b was utilized as an index of individual differences in salient target attentional responding while the slow wave was adopted as an index of variability in task-level sustained attention. Analyses of these components show a significant negative relationship between slow-wave responses to oddball non-targets and perceptual false memory endorsements, suggestive of a link between individual differences in levels of sustained attention and false memory susceptibility. These findings provide the first demonstrated link between individual differences in basic attentional responses and false memory. These results support prior behavioral work linking attention and false memory and highlight the integration between attentional processes and real-world episodic memory.