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 that modulate the likelihood of this failure of awareness, the semantic value of facial emotional expression of the unexpected stimulus is not clear. A total of 457 participants performed a static or a dynamic inattentional blindness paradigm with one of three face icons as the unexpected stimulus. Whereas we only found an effect of frowning faces semantic value on its conscious detection in the static paradigm, we found in both paradigms a substantial effect of frowning as well as happy faces semantic value on their conscious identification. Thus, we assume that the semantic value of unexpected stimuli, based on facial emotional expressions, controls attentional prioritization and influences inattentional blindness. Furthermore, we argue that every finding in inattentional blindness research should be considered in its respective context.

Does hunger promote the detection of foods? The effect of value on inattentional blindness.

Although human perception has evolved into a potent and efficient system, we still fall prey to astonishing failures of awareness as we miss an unexpected object in our direct view when our attention is engaged elsewhere (inattentional blindness). While specific types of value of the unexpected object have been identified to modulate the likelihood of this failure of awareness, it is not clear whether the effect of value on inattentional blindness can be generalized. We hypothesized that the combination of hunger and food-stimuli might increase a more general type of value so that food stimuli have a higher probability to be noticed by hungry participants than by satiated participants. In total, 240 participants were assigned towards a hungry (16 h of fasting) or satiated (no fasting) manipulation and performed afterward a static inattentional blindness task. However, we did not find any effect of value on inattentional blindness based on hunger and food stimuli. We speculate that different underlying mechanisms are involved for different types of value and that value manipulations need to be strong enough to ensure certain value strengths.

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.

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.

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.

What's past is past: Neither perceptual preactivation nor prior motivational relevance decrease subsequent inattentional blindness.

Inattentional blindness-the phenomenon that clearly visible, yet currently unexpected objects go unnoticed when our attention is focused elsewhere-is an ecologically valid failure of awareness. It is currently subject to debate whether previous events and experiences determine whether or not inattentional blindness occurs. Using a simple two-phase paradigm in the present study, we found that the likelihood of missing an unexpected object due to inattention did not change when its defining characteristic (its color) was perceptually preactivated (Experiment 1; N = 188). Likewise, noticing rates were not significantly reduced if the object's color was previously motivationally relevant during an unrelated detection task (Experiment 2; N = 184). These results corroborate and extend recent findings questioning the influence of previous experience on subsequent inattentional blindness. This has implications for possible countermeasures intended to thwart the potentially harmful effects of inattention.

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 performance is related to spatial breadth of attention.

Working memory and attention are closely related constructs. Models of working memory often incorporate an attention component, and some even equate working memory and attentional control. Although some attention-related processes, including inhibitory control of response conflict and interference resolution, are strongly associated with working memory, for other aspects of attention the link is less clear. We examined the association between working-memory performance and attentional breadth, the ability to spread attention spatially. If the link between attention and working memory is broader than inhibitory and interference resolution processes, then working-memory performance might also be associated with other attentional abilities, including attentional breadth. We tested 123 participants on a variety of working-memory and attentional-breadth measures, finding a strong correlation between performances on these two types of tasks. This finding demonstrates that the link between working memory and attention extends beyond inhibitory processes.

Guessing right: Preconscious processing in inattentional blindness.

Much research has been conducted on the determinants of inattentional blindness-the failure to miss an unexpected but salient stimulus in plain view. Far less research has been concerned with the fate of those objects that go unnoticed in such a setting. The available evidence suggests that objects that are not consciously noticed due to inattentional blindness are still processed to a certain degree. The present study substantiated and generalised this limited evidence by reanalysing 16 datasets in regard to participants' guessing accuracy in multiple-choice questions concerning the unexpected object: Participants who did not notice the critical object showed guessing accuracy that lay significantly above chance. Thus, stimuli that are not consciously noticed (i.e., cannot be reported) can nevertheless exert an influence on seemingly random choices. Modality of the primary task as well as performance in the primary task and in a divided-attention trial were evaluated as potential moderators. Methodological limitations such as the design and implementation of the multiple-choice questions and the generalisability of our findings are discussed, and promises of the present approach for future studies are presented.

Loads of unconscious processing: The role of perceptual load in processing unattended stimuli during inattentional blindness.

Inattentional blindness describes the failure to detect an unexpected but clearly visible object when our attention is engaged elsewhere. While the factors that determine the occurrence of inattentional blindness are already well understood, there is still a lot to learn about whether and how we process unexpected objects that go unnoticed. Only recently it was shown that although not consciously aware, characteristics of these stimuli can interfere with a primary task: Classification of to-be-attended stimuli was slower when the content of the task-irrelevant, undetected stimulus contradicted that of the attended, to-be-judged stimuli. According to Lavie's perceptual load model, irrelevant stimuli are likely to reach awareness under conditions of low perceptual load, while they remain undetected under high load, as attentional resources are restricted to the content of focused attention. In the present study, we investigated the applicability of Lavie's predictions for the processing of stimuli that remain unconscious due to inattentional blindness. In two experiments, we replicated that unconsciously processed stimuli can interfere with intended responses. Also, our manipulation of perceptual load did have an effect on primary task performance. However, against our hypothesis, these effects did not interact with each other. Thus, our results suggest that high perceptual load cannot prevent task-irrelevant stimuli that remain undetected from being processed to an extent that enables them to affect performance in a primary task.

Dollars do not determine detection: Monetary value associated with unexpected objects does not affect the likelihood of inattentional blindness.

Conscious perception often fails when an object appears unexpectedly and our attention is focused elsewhere (inattentional blindness). Although various factors have been identified that modulate the likelihood of this failure of awareness, it is not clear whether the monetary reward value associated with an object can affect whether or not this object is detected under conditions of inattention. We hypothesised that unexpectedly appearing objects that contain a feature linked to high value, as established via reward learning in a previous task, would subsequently be detected more frequently than objects containing a feature linked to low value. A total of 537 participants first learned the association between a perceptual feature (colour) and subsequent reward values (high, low, or none reward). Afterwards, participants were randomly assigned to a static (Experiment 1) or dynamic (Experiment 2) inattentional blindness task including an unexpected object associated with high, low, or none reward. However, no significant effect of the previously learned value on the subsequent likelihood of detection was observed. We speculate that artificial monetary value, which is known to affect attentional capture, is not strong enough to determine whether or not an object is consciously perceived.

Inattentional blindness is influenced by exposure time not motion speed.

Inattentional blindness is a striking phenomenon in which a salient object within the visual field goes unnoticed because it is unexpected, and attention is focused elsewhere. Several attributes of the unexpected object, such as size and animacy, have been shown to influence the probability of inattentional blindness. At present it is unclear whether or how the speed of a moving unexpected object influences inattentional blindness. We demonstrated that inattentional blindness rates are considerably lower if the unexpected object moves more slowly, suggesting that it is the mere exposure time of the object rather than a higher saliency potentially induced by higher speed that determines the likelihood of its detection. Alternative explanations could be ruled out: The effect is not based on a pop-out effect arising from different motion speeds in relation to the primary-task stimuli (Experiment 2), nor is it based on a higher saliency of slow-moving unexpected objects (Experiment 3).

The Influence of Attention Set, Working Memory Capacity, and Expectations on Inattentional Blindness.

The probability of inattentional blindness, the failure to notice an unexpected object when attention is engaged on some primary task, is influenced by contextual factors like task demands, features of the unexpected object, and the observer's attention set. However, predicting who will notice an unexpected object and who will remain inattentionally blind has proven difficult, and the evidence that individual differences in cognition affect noticing remains ambiguous. We hypothesized that greater working memory capacity might modulate the effect of attention sets on noticing because working memory is associated with the ability to focus attention selectively. People with greater working memory capacity might be better able to attend selectively to target items, thereby increasing the chances of noticing unexpected objects that were similar to the attended items while decreasing the odds of noticing unexpected objects that differed from the attended items. Our study (N = 120 participants) replicated evidence that task-induced attention sets modulate noticing but found no link between noticing and working memory capacity. Our results are largely consistent with the idea that individual differences in working memory capacity do not predict noticing of unexpected objects in an inattentional blindness task.

Not quite so blind: Semantic processing despite inattentional blindness.

We often fail to detect clearly visible, yet unexpected objects when our attention is otherwise engaged, a phenomenon widely known as inattentional blindness. The potentially devastating consequences and the mediators of such failures of awareness have been studied extensively. Surprisingly, however, hardly anything is known about whether and how we process the objects that go unnoticed during inattentional blindness. In 2 experiments, we demonstrate that the meaning of objects undetected due to inattentional blindness interferes with the classification of attended stimuli. Responses were significantly slower when the semantic content of an undetected stimulus contradicted that of the attended, to-be-judged object. We thus clarify the depth of the "blindness" caused by inattention, as we provide compelling evidence that failing to detect the unexpected does not preclude its processing, even at postperceptual stages. Despite inattentional blindness, our mind obviously still has access to something as refined as meaning. (PsycINFO Database Record

Some See It, Some Don't: Exploring the Relation between Inattentional Blindness and Personality Factors.

Human awareness is highly limited, which is vividly demonstrated by the phenomenon that unexpected objects go unnoticed when attention is focused elsewhere (inattentional blindness). Typically, some people fail to notice unexpected objects while others detect them instantaneously. Whether this pattern reflects stable individual differences is unclear to date. In particular, hardly anything is known about the influence of personality on the likelihood of inattentional blindness. To fill this empirical gap, we examined the role of multiple personality factors, namely the Big Five, BIS/BAS, absorption, achievement motivation, and schizotypy, in these failures of awareness. In a large-scale sample (N = 554), susceptibility to inattentional blindness was associated with a low level of openness to experience and marginally with a low level of achievement motivation. However, in a multiple regression analysis, only openness emerged as an independent, negative predictor. This suggests that the general tendency to be open to experience extends to the domain of perception. Our results complement earlier work on the possible link between inattentional blindness and personality by demonstrating, for the first time, that failures to consciously perceive unexpected objects reflect individual differences on a fundamental dimension of personality.

Does semantic preactivation reduce inattentional blindness?

We are susceptible to failures of awareness if a stimulus occurs unexpectedly and our attention is focused elsewhere. Such inattentional blindness is modulated by various parameters, including stimulus attributes, the observer's cognitive resources, and the observer's attentional set regarding the primary task. In three behavioral experiments with a total of 360 participants, we investigated whether mere semantic preactivation of the color of an unexpected object can reduce inattentional blindness. Neither explicitly mentioning the color several times before the occurrence of the unexpected stimulus nor priming the color more implicitly via color-related concepts could significantly reduce the susceptibility to inattentional blindness. Even putting the specific color concept in the main focus of the primary task did not lead to reduced inattentional blindness. Thus, we have shown that the failure to consciously perceive unexpected objects was not moderated by semantic preactivation of the objects' most prominent feature: its color. We suggest that this finding reflects the rather general principle that preactivations that are not motivationally relevant for one's current selection goals do not suffice to make an unexpected object overcome the threshold of awareness.

Inattentional Blindness and Individual Differences in Cognitive Abilities.

People sometimes fail to notice salient unexpected objects when their attention is otherwise occupied, a phenomenon known as inattentional blindness. To explore individual differences in inattentional blindness, we employed both static and dynamic tasks that either presented the unexpected object away from the focus of attention (spatial) or near the focus of attention (central). We hypothesized that noticing in central tasks might be driven by the availability of cognitive resources like working memory, and that noticing in spatial tasks might be driven by the limits on spatial attention like attention breadth. However, none of the cognitive measures predicted noticing in the dynamic central task or in either the static or dynamic spatial task. Only in the central static task did working memory capacity predict noticing, and that relationship was fairly weak. Furthermore, whether or not participants noticed an unexpected object in a static task was only weakly associated with their odds of noticing an unexpected object in a dynamic task. Taken together, our results are largely consistent with the notion that noticing unexpected objects is driven more by stochastic processes common to all people than by stable individual differences in cognitive abilities.

Independent effects of temporal expectation and stimulus intensity in audition.

Temporal orienting--that is, selective attention to instants in time--has been shown to modulate performance in terms of faster responses in a variety of paradigms. Electrophysiological recordings have shown that temporal orienting modulates neural processing at early, probably perceptual, and late, probably decision- or response-related, stages. Recently, it was shown that the effect of temporal orienting on early auditory brain potentials is independent of the effect of the physical sound feature intensity. This indicates that temporal orienting might not affect stimulus processing by increasing the sensory gain of attended stimuli. In the present study, we investigated whether the independence of temporal-orienting and sound-intensity effects could be replicated behaviorally. Sequences were presented that were either rhythmic, most likely creating temporal expectations, or arrhythmic, presumably not creating such expectations. As hypothesized, the main effects of temporal expectation and sound intensity on reaction times were independent (Experiment 1). The exact pattern of results was replicated with a slightly altered paradigm (Experiment 2) and with a different kind of task (Experiment 3). In sum, these results corroborate the notion that the effect of temporal orienting might not rely on the same processes as the effect of sound intensity does.