Inattentional blindness for a noxious multimodal stimulus

Previous research has shown that people can miss salient stimuli outside the focus of their attention. This phenomenon, called inattentional blindness, typically is observed when people are given a task requiring them to focus their attention on one aspect of a complex visual scene. While participants are doing this task, an unexpected stimulus appears, and participants' awareness of it is tested shortly thereafter. In the present experiments, noxious bimodal stimuli were used as a test case to measure the strength of inattentional blindness. We tested whether participants would notice a person enter a scene and scratch her fingernails down a chalkboard (thus making a sound called a "gride"). A large proportion of participants failed to detect this event even when the noxious audio associated with it was strengthened and isolated in time from surrounding noises.     

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.     

Inattentional deafness in music

While inattentional blindness is a modern classic in attention and perception research, analogous phenomena of inattentional deafness have been widely neglected. We here present the first investigation of inattentional deafness in and with music under controlled experimental conditions. Inattentional deafness in music is defined as the inability to consciously perceive an unexpected musical stimulus when attention is focused on a certain facet of the piece. Participants listened to a modification of the first 1′50″ of Richard Strauss’ Thus Spake Zarathustra; while the control group just listened, the experimental group had to count the number of timpani beats. An e-guitar solo served as the unexpected event. In Study 1, experimental data from n = 115 participants were analyzed. Non-musicians were compared with musicians to investigate the impact of expertise. In Study 2 (n = 47), the scope of the inattentional deafness effect was investigated with a more salient unexpected stimulus. Results demonstrate an inattentional deafness effect under dynamic musical conditions. Quite unexpectedly, the effect was structurally equivalent even for musicians. Our findings clearly show that sustained inattentional deafness exists in the musical realm, in close correspondence to inattentional blindness with dynamic visual stimuli.     

Gorillas we have missed: sustained inattentional deafness for dynamic events

It is now well-known that the absence of attention can leave us 'blind' to visual stimuli that are very obvious under normal viewing conditions (e.g. a person dressed as a gorilla; Simons & Chabris, 1999). However, the question of whether hearing can ever be susceptible to such effects remains open. Here, we present evidence that the absence of attention can leave people 'deaf' to the presence of an 'auditory gorilla' which is audible for 19s and clearly noticeable under full attention. These findings provide the first ever demonstration of sustained inattentional deafness. The effect is all the more surprising because it occurs within a lifelike, three-dimensional auditory scene in which the unnoticed stimulus moves through the middle of several other dynamic auditory stimuli.     

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.     

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.     

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.     

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 effects of aging on a measure of prospective remembering using naturalistic stimuli

The aim of this study was to determine the effect of age on the noticing and memory search stages of a prospective memory task. Three groups (n=30) of older, middle‐aged, and younger persons were compared on a task using naturalistic stimuli, designed to simulate prospective remembering in everyday life. Participants were given a list of 30 instructions, each comprising an action (e.g. [Buy a hamburger]) and associated cue (e.g. [At McDonalds]). They then watched a videotape showing the view a person would have walking along a city street and attempted to recall each task when the cue appeared. The key finding was that older participants had a disproportionate reduction in recall of actions relative to cues noticed compared to both younger and middle‐aged participants. Although the older group were significantly less likely to notice cues than were the younger participants, noticing was preserved relative to memory search. The implication of this is that noticing complex and naturalistic visual cues in a shopping environment may rely primarily on automatic memory processes, whereas memory search depends on more strategic and conscious memory processes. Copyright © 2004 John Wiley & Sons, Ltd.     

Out of sight, out of mind: the rarity of assessing and reporting participants' visual abilities when studying perception of linguistic stimuli

Variations in visual abilities are widespread in the adult population and have profound effects on processing linguistic stimuli (text, words, letters). However, a review of articles (1442) investigating the processing of visually presented linguistic stimuli by non-clinical adult participants, published in 2000-2010 in five leading journals (Journal of Experimental Psychology: Human Perception and Performance; Journal of Experimental Psychology: Learning, Memory, and Cognition; Memory & Cognition; Perception & Psychophysics/Attention, Perception, & Psychophysics; and Perception), showed that the majority of articles (73.5%) made no mention of participants' visual abilities (62.1%) or relied merely on participants' self-report (11.4%). 25.2% reported participants' visual abilities with no assessment, and only 1.2% reported participants' visual abilities following objective assessment; the highest percentage of articles within this laudable minority was in Perception. The indications are that objective visual assessments in studies of visually presented linguistic stimuli are rare and greater use would facilitate better understanding of the visuo-cognitive processes involved.     

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.     

The effect of fearful faces on the attentional blink is task dependent

In a set of three rapid serial visual presentation experiments, we investigated the effect of fearful and neutral face stimuli on the report of trailing scene targets. When the emotional expression of the face stimuli had to be indicated, fearful faces induced a stronger attentional blink (AB) than did neutral faces. However, with identical physical stimulation, the enhancement of the AB by fearful faces disappeared when participants had to judge the faces’ gender. If faces did not have to be reported, no AB was observed. Thus, fearful faces exhibited an effect on the AB that crucially depended on the observer’s attentional set. Hence, the AB can be influenced by an emotional T1 when T1 has to be reported, but this influence is modulated by task context. This result indicates a close connection between temporal attention and emotional processing that is modulated by task context.     

The eye gaze direction of an observed person can bias perception,memory, and attention in adolescents with and without autism spectrum disorder

The reported experiments aimed to investigate whether a person and his or her gaze direction presented in the context of a naturalistic scene cause perception, memory, and attention to be biased in typically developing adolescents and high-functioning adolescents with autism spectrum disorder (ASD). A novel computerized image manipulation program presented a series of photographic scenes, each containing a person. The program enabled participants to laterally maneuver the scenes behind a static window, the borders of which partially occluded the scenes. The gaze direction of the person in the scenes spontaneously cued attention of both groups in the direction of gaze, affecting judgments of preference (Experiment 1a) and causing memory biases (Experiment 1b). Experiment 2 showed that the gaze direction of a person cues visual search accurately to the exact location of gaze in both groups. These findings suggest that biases in preference, memory, and attention are caused by another person’s gaze direction when viewed in a complex scene in adolescents with and without ASD     

Coming Out in Voices

This paper articulates the personal experiences of a woman with a physical disability who enters therapy to explore issues involving lesbian identity, health and illness, disability oppression and pride, and relationships. Written in the first person, the article uses anecdotes, poetry, and journal entries to chart the author's process of self-discovery. As a woman, a lesbian, and a person with a disability, the author frequently finds herself at odds with the culture around her. This creates conflicts between the author's real self, and the self she must present to others. She discusses how she had learned to "silence the voices" which were not useful in challenging the stereotypes, making others comfortable, or communicating with assistants. The author describes how therapy offered her the opportunity to unlearn the silence, value all of her voices, listen to herself, resolve her internal dilemmas, and develop a deeper sense of self.     

Using inattentional blindness as an operational definition of unattended: The case of surface completion

Studying inattentional processing is made difficult by the fact that measuring it often results in observers attending to the stimuli in question. Here it is suggested that inattentional blindness—the lack of awareness of stimuli that appear in unattended regions of the visual field—be used as an operational definition of unattended. Separate online measures, taken while the stimuli are still present, can then be used to probe specific aspects of processing. Applying this method to the perceptual completion of partial surfaces, an online measure of modal and amodal completion was developed, and then used within an experiment in which inattentional blindness to the surfaces was assessed. The results indicated that surface completion can be engaged by unattended stimuli. More generally, the study illustrates the usefulness of this approach for probing what processing does and does not occur for stimuli that appear in unattended regions of the visual field.     

The effect of spatial and nonspatial contextual information on visual object memory

Recent research has found visual object memory can be stored as part of a larger scene representation rather than independently of scene context. The present study examined how spatial and nonspatial contextual information modulate visual object memory. Two experiments tested participants’ visual memory by using a change detection task in which a target object's orientation was either the same as it appeared during initial viewing or changed. In addition, we examined the effect of spatial and nonspatial contextual manipulations on change detection performance. The results revealed that visual object representations can be maintained reliably after viewing arrays of objects. Moreover, change detection performance was significantly higher when either spatial or nonspatial contextual information remained the same in the test image. We concluded that while processing complex visual stimuli such as object arrays, visual object memory can be stored as part of a comprehensive scene representation, and both spatial and nonspatial contextual changes modulate visual memory retrieval and comparison.     

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.     

The role of social meaning in inattentional blindness: When the gorillas in our midst do not go unseen

Without visual attention, even the obvious–like a gorilla walking through a scene of people–goes undetected (Mack & Rock, 1998; Simons & Chabris, 1999). This “inattentional blindness” is a persistent, well-documented limitation of the human visual system. The current research examines whether social meaning reduces this visual bias by imbuing unexpected objects with signal value, thus increasing their relevance and facilitating perception. Using one of the most established illustrations of inattentional blindness, we show for the first time that activating a social association, even an erroneous one (i.e., the African American–ape association), drastically attenuates inattentional blindness. This is not accounted for by visual feature matching. Rather, these results suggest that social meaning, even when flawed, may direct our visual system towards associated visual information that would otherwise be overlooked. As such, these results provide a powerful replication of the African American–ape association and illustrate that this broadly held association has the power to spontaneously change the content of one's visual world.     

The effects of eye movements, age, and expertise on inattentional blindness

Based on various stimuli, the findings for the inattentional blindness paradigm suggest that many observers do not perceive an unexpected object in a dynamic setting. In a first experiment, inattentional blindness was combined with eye tracking data from children. Observers who did not notice the unexpected object in the basketball game test by spent on average as much time (about one second) looking at the unexpected object as those subjects who did perceive it. As such, individual differences that are responsible for the recognition of unexpected objects have to be found as further indicators. In a second experiment, the expert-novice paradigm was used to show that the probability of seeing an unexpected object can be increased with specific previous experience. The results in the same task indicate significant differences between basketball experts and basketball novices. The ages of the subjects in both experiments are discussed in connection with the inattentional blindness paradigm.     

Group membership influences social control of perpetrators of uncivil behaviors

The present research examined bystanders' reactions to uncivil behaviors. We tested a proposed mediator of the effect by which bystanders are more likely to exert social control over in‐group compared to out‐group members. Participants were asked to report their likely reaction if they were to witness a woman throwing a plastic bottle into a flowerbed. Participants reported that they were more likely to express their disapproval to the woman if she was an in‐group rather than an out‐group member. This effect was mediated by the moral emotions that participants expected the woman to feel if they were to intervene: Participants expected the woman to feel more embarrassment and shame when she was an in‐group member, and this explained why they were more likely to exert social control toward an in‐group member than an out‐group member. Copyright © 2009 John Wiley & Sons, Ltd.