The role of unattended distractors in sustained inattentional blindness

When participants are attending to a subset of visual targets or events and ignoring irrelevant distractors (“selective looking”), they often fail to detect the appearance of an unexpected visual object or event even when the object is visible for several seconds (“sustained inattentional blindness”). An important factor influencing detection rates in selective looking is the attentional set of the participant: the more similar the features of the unexpected object are to the attended ones, the more probably it will be detected. We examined the possible contribution of active ignoring to this similarity effect by studying the role of the distractor objects in sustained inattentional blindness. First we showed the similarity effect for chromatic colors and then we manipulated the similarity of the unexpected object in relation to the distractor objects and did not find any effects. Moreover, we found that inattentional blindness was present even when the displays did not contain any irrelevant to-be-ignored objects. We conclude that attending to target items on the basis of attentional set, but not active ignoring of nontargets items, is sufficient for the occurrence of sustained inattentional blindness.     

Gorillas in our midst: sustained inattentional blindness for dynamic events

With each eye fixation, we experience a richly detailed visual world. Yet recent work on visual integration and change direction reveals that we are surprisingly unaware of the details of our environment from one view to the next: we often do not detect large changes to objects and scenes ('change blindness'). Furthermore, without attention, we may not even perceive objects ('inattentional blindness'). Taken together, these findings suggest that we perceive and remember only those objects and details that receive focused attention. In this paper, we briefly review and discuss evidence for these cognitive forms of 'blindness'. We then present a new study that builds on classic studies of divided visual attention to examine inattentional blindness for complex objects and events in dynamic scenes. Our results suggest that the likelihood of noticing an unexpected object depends on the similarity of that object to other objects in the display and on how difficult the priming monitoring task is. Interestingly, spatial proximity of the critical unattended object to attended locations does not appear to affect detection, suggesting that observers attend to objects and events, not spatial positions. We discuss the implications of these results for visual representations and awareness of our visual environment.     

What you see is what you set: sustained inattentional blindness and the capture of awareness

This article reports a theoretical and experimental attempt to relate and contrast 2 traditionally separate research programs: inattentional blindness and attention capture. Inattentional blindness refers to failures to notice unexpected objects and events when attention is otherwise engaged. Attention capture research has traditionally used implicit indices (e.g., response times) to investigate automatic shifts of attention. Because attention capture usually measures performance whereas inattentional blindness measures awareness, the 2 fields have existed side by side with no shared theoretical framework. Here, the authors propose a theoretical unification, adapting several important effects from the attention capture literature to the context of sustained inattentional blindness. Although some stimulus properties can influence noticing of unexpected objects, the most influential factor affecting noticing is a person's own attentional goals. The authors conclude that many--but not all--aspects of attention capture apply to inattentional blindness but that these 2 classes of phenomena remain importantly distinct.     

Predicting and manipulating the incidence of inattentional blindness

Inattentional blindness (IB) occurs when an observer, who is engaged in a resource-consuming task, fails to notice an unexpected although salient stimulus appearing in their visual field. The incidence of IB is affected by changes in stimulus-driven properties, but little research has examined individual differences in IB propensity. We examine working memory capacity (WMC), processing styles (flicker task), inhibition (Stroop task), and training in predicting IB. WMC is associated with IB (Experiments 1 and 2) but neither processing style (Experiment 1) nor inhibition (Experiment 2) was associated. In Experiment 2, prior training on a task reduced the incidence of IB compared to no prior training, and this effect was significantly larger when trained on the same tracking task as that used in the IB task rather than a different task. We conclude that IB is related to WMC and that training can influence the incidence of IB.     

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.     

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.     

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.     

Beyond inattentional blindness and attentional misdirection: From attentional paradigms to attentional mechanisms

Memmert (2010) tried to foster the development of attentional research by discussing four differences between attentional misdirection (AM) and inattentional blindness (IB). Considering this goal, the comment was received in the intended way by the comments of (Most, 2010) and (Moran and Brady, 2010) who make a number of highly valuable suggestions for further progress. As initially suggested by Memmert (2010) this dialog should help unravel the underlying attentional mechanisms of different paradigms. Therefore, we first discuss the suggested distinction between central and spatial IB by Most (2010). Second, we argue that working memory and perceptual load research seem particularly interesting in this regard and should be taken into consideration when conducting future research along the lines of IB and AM. Third, representative task designs can be an important mosaic piece in across-the-board attention theories and highly useful for deriving further testable hypothesis in naturalistic settings. The most important claim of all commentaries in this issue is that the proposed ideas can all be empirically tested and thereby contribute to the advancement of an unified theoretical framework incorporating IB, AM in consideration of overt and covert attention mechanisms.     

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.     

Misdirected by the gap: the relationship between inattentional blindness and attentional misdirection

In several of our articles we have drawn analogies between inattentional blindness paradigms and misdirection. Memmert (2010) however, has criticized this analogy and urged for caution in assuming too much of a close relationship between these two phenomena. Here we consider the points raised by Memmert and highlight some misunderstandings and omissions in his interpretation of our work, which substantially undermine his argument. Debating the similarities and differences between aspects of misdirection and inattentional blindness is valuable and has the potential to highlight the utility of these two phenomena. However, it is important not to be misdirected by subtle differences between particular instances of each phenomenon, at the expense of failing to detect the opportunities that these phenomena present for extending our understanding of attention and awareness.     

Reflexive orienting by central arrows: Evidence from the inattentional blindness task

It was demonstrated that central arrows produce orienting of attention even when they are nonpredictive as to the target location. This finding was suggested to indicate reflexive orienting of attention by central arrows. However, it is not clear whether central arrows can produce an attentional effect without awareness. In two experiments, using a variation of the inattentional blindness task, we examine whether orienting of attention by a central arrow can be demonstrated without conscious perception of the arrow. We found that attention could be directed to the cued location even when the arrow was not consciously perceived.     

Dissociation of processing time and awareness by the inattentional blindness paradigm

Consciousness researchers are interested in distinguishing between mental activity that occurs with and without awareness (i.e., explicit versus implicit processes). The inattentional blindness (IB) paradigm is an excellent tool for this question because it permits the independent manipulation of processing time and awareness. In the present study, we show that implicit texture segregation can occur during inattentional blindness, provided that the texture is exposed for a sufficient duration. In contrast, a Simon effect does not occur during inattentional blindness, even with similar exposure duration of the critical stimulus. This reveals a dissociation between processing time and awareness, consistent with the possibility of separate processing streams for explicit and implicit visual perception.     

Minds on the blink: The relationship between inattentional blindness and attentional blink

Failures of conscious visual awareness occur when specific task demands prevent an observer from detecting a stimulus that would otherwise be clearly visible. Two examples are inattentional blindness (IB) and attentional blink (AB). IB is the failure to detect an unexpected stimulus when attention is otherwise engaged. AB describes the inability to detect a second target that is presented within 180-500?ms of the first target. Previous research has suggested that similar cognitive processes underlie both IB and AB; however, they are distinct phenomena, and no evidence has directly linked the two. We tested the same group of observers on an IB task and an AB task. Consistent with our hypotheses, we found that "non-noticers" who failed to detect an unexpected stimulus in the IB task also demonstrated a larger AB effect. This suggests that some observers may be more generally susceptible to failures of conscious visual awareness, regardless of specific context.     

Clarifying the effect of facial emotional expression on inattentional blindness

Conscious perception often fails when an object appears unexpectedly and our attention is focused elsewhere (inattentional blindness). While various factors have been identified as determinants of inattentional blindness, the influence of an unexpected object́s semantic value remains ambiguous. This is also true for the supposedly evolutionary meaning of faces; some studies found higher detection rates for faces while others did not or used control conditions that differed in physical aspects of the stimulus as well. In the proposed studies we aim to replicate and clarify the effect of the semantic value of faces on inattentional blindness in a controlled and systematic manner.     

New objects do not capture attention without a top-down setting: Evidence from an inattentional blindness task

Past studies have suggested that a new object can involuntarily capture attention in a visual search task (Yantis & Jonides, 1984 Yantis, S. and Jonides, J. 1984. Abrupt visual onsets and selective attention: Evidence from visual search. Journal of Experimental Psychology: Human Perception and Performance, 10: 601–621. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). However, trials in these experiments usually begin with abrupt onsets that are considered to signal new objects; thus, there may be a bias toward paying attention to new objects. We examine whether new objects can still capture attention when this bias is excluded, using an inattentional blindness task. Our results showed that when the trials began with new objects, a new object captured attention. When new objects were totally irrelevant and all top-down settings for new objects were prevented, a new object did not capture attention. Our findings argue against the view that new objects capture attention in a purely stimulus-driven fashion.     

Examining effects of preconscious mere exposure: An inattentional blindness approach

An increase in affective preference for stimuli, which a person has been repeatedly exposed to, is known as mere exposure effect. This effect has been shown for stimuli that are processed subliminally, that is, below the threshold of awareness. This study fills a current research gap by investigating mere exposure effects under processing that is preconscious, which follows from a high stimulus strength but absence of top-down amplification. In three experiments (N = 240 in total) preconscious processing was evoked using an inattentional blindness paradigm, which allowed the processing of stimuli (nonwords or Chinese symbols) under complete inattention. Contrary to our hypothesis, we did not find a mere exposure effect in our experiments. We expand the current state of knowledge by discussing the distractor devaluation effect and the attentional set of participants as possible reasons for the absence of the mere exposure effect. Directions for future investigations are outlined.     

Attention set for number: expectation and perceptual load in inattentional blindness

Inattentional blindness is the failure to detect unexpected events when attention is otherwise engaged. Previous research indicates that inattentional blindness increases as perceptual demands intensify. The authors present 6 cuing experiments that manipulated both the perceptual demands of a primary letter-naming task and the expectations of the individual. Inattentional blindness was greatest for individuals who held a numerical expectation that was consistent with the number of primary-task items presented. Expectation also affected detection differentially at various levels of perceptual load: Detection at moderate and high perceptual load was significantly affected by expectation, whereas detection at low perceptual load was not. The authors suggest that at moderate to high levels of perceptual load, individuals whose numerical expectations are fulfilled terminate processing when the primary task is complete, at the expense of the unexpected visual event. These experiments provide compelling evidence that expectations do affect detection of an unexpected stimulus, and they are the first to demonstrate that individuals set their attention for the number of items to be detected and are vulnerable to inattentional blindness whenever their primary-task numerical expectation is fulfilled.     

Attentional biases in social anxiety: an investigation using the inattentional blindness paradigm

One line of research has examined attentional bias as a potential maintenance factor in social anxiety using cognitive experiment paradigms. The present study sought to examine the utility of the inattentional blindness (IB) paradigm for assessing attentional bias in social anxiety. Unlike other existing paradigms such as the emotional Stroop or dot-probe tasks, the IB paradigm has the advantage of eliminating the individual's expectation and intention to search for social cues, which would reduce strategic or effortful responses. Two independent experiments were conducted using college students scoring high or low on the Fear of Negative Evaluation Scale. In both Experiments 1 and 2, participants were randomized to one of three IB experiment conditions, in which a positive face, a negative face, or a neutral item was unexpectedly presented, in the presence/absence of a bogus-speech threat. The overall pattern of our data suggests the presence of hypervigilant attentional processing in social anxiety. The IB paradigm appears to be a useful addition to existing experiment paradigms for investigating attentional bias in social anxiety and perhaps other psychopathology.     

Intentional and Phenomenal Properties: How not to be Inseparatists

Philosophia - In this paper I give an overview of the recent developments in the phenomenalism – intentionalism debate and try to show that the proposed solutions of neither sides are...