Change blindness and visual memory: Visual representations get rich and act poor

People often fail to detect large changes to visual scenes following a brief interruption, an effect known as ‘change blindness’. People with autism spectrum conditions (ASC) have superior attention to detail and better discrimination of targets, and often notice small details that are missed by others. Together these predict people with autism should show enhanced perception of changes in simple change detection paradigms, including reduced change blindness. However, change blindness studies to date have reported mixed results in ASC, which have sometimes included no differences to controls or even enhanced change blindness. Attenuated change blindness has only been reported to date in ASC in children and adolescents, with no study reporting reduced change blindness in adults with ASC. The present study used a change blindness flicker task to investigate the detection of changes in images of everyday life in adults with ASC (n = 22) and controls (n = 22) using a simple change detection task design and full range of original scenes as stimuli. Results showed the adults with ASC had reduced change blindness compared to adult controls for changes to items of marginal interest in scenes, with no group difference for changes to items of central interest. There were no group differences in overall response latencies to correctly detect changes nor in the overall number of missed detections in the experiment. However, the ASC group showed greater missed changes for marginal interest changes of location, showing some evidence of greater change blindness as well. These findings show both reduced change blindness to marginal interest changes in ASC, based on response latencies, as well as greater change blindness to changes of location of marginal interest items, based on detection rates. The findings of reduced change blindness are consistent with clinical reports that people with ASC often notice small changes to less salient items within their environment, and are in-line with theories of enhanced local processing and greater attention to detail in ASC. The findings of lower detection rates for one of the marginal interest conditions may be related to problems in shifting attention or an overly focused attention spotlight.

Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. While many laboratory procedures have been developed that produce change blindness in humans, the flicker paradigm has emerged as a particularly effective method. In the flicker paradigm, two visual displays are presented in alternation with one another. If successive displays are separated by a short inter-stimulus interval (ISI), change detection is impaired. The simplicity of the procedure and the clear, performance-based operational definition of change blindness make the flicker paradigm well-suited to comparative research using nonhuman animals. Indeed, a variant has been developed that can be implemented in operant chambers to study change blindness in pigeons. Results indicate that pigeons, like humans, are worse at detecting the location of a change if two consecutive displays are separated in time by a blank ISI. Furthermore, pigeons' change detection is consistent with an active, location-by-location search process that requires selective attention. The flicker task thus has the potential to contribute to investigations of the dynamics of pigeons' selective spatial attention in comparison to humans. It also illustrates that the phenomenon of change blindness is not exclusive to humans' visual perception, but may instead be a general consequence of selective attention. Finally, while the useful aspects of attention are widely appreciated and understood, it is also important to acknowledge that they may be accompanied by specific imperfections such as change blindness, and that these imperfections have consequences across a wide range of contexts.

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.

Change detection is required in monitoring and managing complex situations such as air traffic control. Considering that change blindness—the incapacity to detect changes in a visual scene—is a considerable source of human errors and that most studies on change detection have involved static visual scenes, it is crucial to evaluate existing tools designed to help this cognitive function in complex dynamic situations. The goal of the present study was to determine the efficacy of the Change History Explicit (CHEX)—a tool already proven effective when explicit change detection is the only task to execute—when change detection is implicit and intrinsic to a more complex task. Results revealed that the CHEX failed to improve implicit change detection when this task was embedded in a threat-evaluation and weapon-assignment (TEWA) task. Moreover, TEWA performance was hindered and mental workload was perceived as higher when the CHEX was available. Even when the information load imposed by the CHEX was reduced, the tool remained ineffective. This suggests that the nature of the change detection task should be taken into account when designing a decision support system.

Detecting changes in an ever-changing environment is highly advantageous, and this ability may be critical for survival. In the present study, we investigated the neural substrates of change detection in the context of a visual working memory task. Subjects maintained a sample visual stimulus in short-term memory for 6 s, and were asked to indicate whether a subsequent, test stimulus matched or did not match the original sample. To study change detection largely uncontaminated by attentional state, we compared correct change and correct no-change trials at test. Our results revealed that correctly detecting a change was associated with activation of a network comprising parietal and frontal brain regions, as well as activation of the pulvinar, cerebellum, and inferior temporal gyrus. Moreover, incorrectly reporting a change when none occurred led to a very similar pattern of activations. Finally, few regions were differentially activated by trials in which a change occurred but subjects failed to detect it (change blindness). Thus, brain activation was correlated with a subject's report of a change, instead of correlated with the physical change per se. We propose that frontal and parietal regions, possibly assisted by the cerebellum and the pulvinar, might be involved in controlling the deployment of attention to the location of a change, thereby allowing further processing of the visual stimulus. Visual processing areas, such as the inferior temporal gyrus, may be the recipients of top-down feedback from fronto-parietal regions that control the reactive deployment of attention, and thus exhibit increased activation when a change is reported (irrespective of whether it occurred or not). Whereas reporting that a change occurred, be it correctly or incorrectly, was associated with strong activation in fronto-parietal sites, change blindness appears to involve very limited territories.

The ability to accurately retrieve visual details of past events is a fundamental cognitive function relevant for daily life. While a visual stimulus contains an abundance of information, only some of it is later encoded into long-term memory representations. However, an ongoing challenge has been to isolate memory representations that integrate various visual features and uncover their dynamics over time. To address this question, we leveraged a novel combination of empirical and computational frameworks based on the hierarchal structure of convolutional neural networks and their correspondence to human visual processing. This enabled to reveal the contribution of different levels of visual representations to memory strength and their dynamics over time. Visual memory strength was measured with distractors selected based on their shared similarity to the target memory along low or high layers of the convolutional neural network hierarchy. The results show that visual working memory relies similarly on low and high-level visual representations. However, already after a few minutes and on to the next day, visual memory relies more strongly on high-level visual representations. These findings suggest that visual representations transform from a distributed to a stronger high-level conceptual representation, providing novel insights into the dynamics of visual memory over time.

Driver sleepiness is a leading contributor to road crashes. Sleep-related crashes are more likely to involve collision with a stationary object than non-sleep-related crashes. The mechanism underpinning this is unknown; one potential explanation may be an increased propensity for change blindness. Twenty-four drivers with at least one year of independent driving experience completed two simulated drives: one following a normal night of sleep (7–8 h) and one following sleep restriction (5 h). The drive consisted of 5 laps of an 11.3 km circuit, taking approximately 45 min. Each lap comprised half urban and half rural driving environments. Twenty times during the drive the visual screen was blanked for 500 ms, and when it reappeared participants were asked whether there were any changes. Twelve times a change occurred, and eight times no change occurred. Additionally, four unexpected changes occurred; for example, the language of the road signs was changed from English to German. At the end of each drive, participants were asked if anything unusual occurred. Sleep loss resulted in significantly increased subjective sleepiness and subjective workload. Driving in an urban environment did not increase alertness; subjective sleepiness ratings did not significantly differ between urban and rural environments. Change detection accuracy for both cued and unexpected changes was not significantly affected by sleep loss. In line with previous research, accuracy was greater for changes with high safety relevance and those occurring in rural environments. Collectively the findings of the study suggest that increase change blindness is probably not a contributor to sleep-related road crashes; however, future on-road research and with greater levels of sleep loss is needed to confirm findings.

Our ability to actively maintain information in visual memory is strikingly limited. There is considerable debate about why this is so. As with many questions in psychology, the debate is framed dichotomously: Is visual working memory limited because it is supported by only a small handful of discrete "slots" into which visual representations are placed, or is it because there is an insufficient supply of a "resource" that is flexibly shared among visual representations? Here, we argue that this dichotomous framing obscures a set of at least eight underlying questions. Separately considering each question reveals a rich hypothesis space that will be useful for building a comprehensive model of visual working memory. The questions regard (1) an upper limit on the number of represented items, (2) the quantization of the memory commodity, (3) the relationship between how many items are stored and how well they are stored, (4) whether the number of stored items completely determines the fidelity of a representation (vs. fidelity being stochastic or variable), (5) the flexibility with which the memory commodity can be assigned or reassigned to items, (6) the format of the memory representation, (7) how working memories are formed, and (8) how memory representations are used to make responses in behavioral tasks. We reframe the debate in terms of these eight underlying questions, placing slot and resource models as poles in a more expansive theoretical space.

Participants in incidental change detection studies often miss large changes to visually salient or conceptually relevant objects such as actor substitutions across video cuts, but there are competing explanations of why participants fail to detect these changes. According to an integrative processing account, object-based attention typically induces integrated representation and comparison processes sufficient to detect changes to that object. On this view, participants miss changes in incidental paradigms because those paradigms fail to elicit the level of attention necessary to trigger integrated representation and comparison processes. In contrast, a selective processing account posits that representation and comparison processes needed to detect changes do not occur by default, even for attended objects, but are only elicited in response to specific functional needs. In four experiments, we tested detection of actor substitutions when participants engaged in tasks that required actor identity processing but did not necessarily require the combination of processes necessary to detect changes. Change blindness for actor substitutions persisted when participants counted the number of actors in the video and sometimes persisted when participants were instructed to remember the substituted actor for later recall. Change blindness consistently diminished, however, when participants were shown the prechange actor before or during the video and instructed to search for that actor in the video. Our results refine the contrast between selective and integrative processing by specifying how task demands to create durable visual representations can remain independent of comparison processes, while search demands can induce integrative comparison processes in a naturalistic setting. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Using a machine-learning classification algorithm applied to near-infrared spectroscopy (NIRS) signals, we classify a success (change detection) or a failure (change blindness) in detecting visual changes for a change-detection task. Five subjects perform a change-detection task, and their brain activities are continuously monitored. A support-vector-machine algorithm is applied to classify the change-detection and change-blindness trials, and correct classification probability of 70-90% is obtained for four subjects. Two types of temporal shapes in classification probabilities are found: one exhibiting a maximum value after the task is completed (postdictive type), and another exhibiting a maximum value during the task (predictive type). As for the postdictive type, the classification probability begins to increase immediately after the task completion and reaches its maximum in about the time scale of neuronal hemodynamic response, reflecting a subjective report of change detection. As for the predictive type, the classification probability shows an increase at the task initiation and is maximal while subjects are performing the task, predicting the task performance in detecting a change. We conclude that decoding change detection and change blindness from NIRS signal is possible and argue some future applications toward brain-machine interfaces.

Combining theoretical hypotheses of infant cognition and adult perception, we present evidence that infants can maintain visual representations despite their failure to detect a change. Infants under 12 months typically fail to notice a change to an object's height in a covering event. The present experiments demonstrated that 11-month-old infants can nevertheless maintain a viable representation of both the pre- and post-change heights despite their 'change blindness'. These results suggest that infants, like adults, can simultaneously maintain multiple representations, even if they do not optimally use them.

Despite the importance of change detection (CD) for visual perception and for performance in our environment, observers often miss changes that should be easily noticed. In the present study, we employed time-frequency analysis to investigate the neural activity associated with CD and change blindness (CB). Observers were presented with two successive visual displays and had to look for a change in orientation in any one of four sinusoid gratings between both displays. Theta power increased widely over the scalp after the second display when a change was consciously detected. Relative to no-change and CD, CB was associated with a pronounced theta power enhancement at parietal-occipital and occipital sites and broadly distributed alpha power suppression during the processing of the prechange display. Finally, power suppressions in the beta band following the second display show that, even when a change is not consciously detected, it might be represented to a certain degree. These results show the potential of time-frequency analysis to deepen our knowledge of the temporal curse of the neural events underlying CD. The results further reveal that the process resulting in CB begins even before the occurrence of the change itself.

One promising means of overcoming data overload in complex domains is through the introduction of tactile displays, which can offload the overburdened visual channel. However, the effectiveness of tactile displays depends on taking into consideration attentional systems and the limitations of the human perception. One important question is the extent to which the tactile modality is susceptible to change blindness, i.e. the failure to detect even large and expected changes when these changes coincide with a “transient” stimulus. Recent research has demonstrated an analog of change blindness in the tactile modality for pattern change recognition. The present study examined whether tactile change blindness, as well as crossmodal visual-tactile change blindness, occurs in the context of search and monitoring tasks, and whether it is affected by the addition of a secondary task. The application domain for this experiment was simulated Unmanned Aerial Vehicle control. The findings confirmed the occurrence of tactile change blindness; however, no crossmodal change blindness was observed and change detection was unaffected by the addition of a secondary search task. Overall, this research add to the knowledge base in multimodal and redundant information processing and can inform the design of multimodal displays for complex, data-rich domains.

Numerous studies have demonstrated that observers often fail to notice large changes in visual scenes, a phenomenon known as change blindness. Some experiments have suggested that phenomenological experience in change blindness experiments is more diverse than the common distinction between change detection and change blindness allows to resolve. Recently, it has been debated whether changes in visual scenes can be detected ("sensed") without a corresponding perception of the changing object ("seeing") and whether these phenomena build on fundamentally different perceptual processes. The present study investigated whether phenomenologically different perceptual processes such as sensing and seeing rely on different or similar neural processes. We studied ERP effects of visual change processing (as compared to change blindness) when observers merely detected the presence of a change ("sensing") and when they identified the changing object in addition to detection ("seeing"). Although the visual awareness negativity (VAN)/selection negativity was similar for detection with and without identification, a change-related positivity and the N2pc contralateral to changes were found exclusively when the change was fully identified. This finding indicates that change identification requires perceptual and neural processes that are not involved in mere detection. In a second experiment, we demonstrated that the VAN and N2pc effects are similar to effects of selective attention in a visual search task. By contrast, the change-related positivity was specific for conscious processing of visual changes. The results suggest that changes can be detected ("sensed") without perception of the changing object. Furthermore, sensing and seeing seem to rely on different neural processes and seem to constitute different types of visual perception. These findings bear implications for how different categories of visual awareness are related to different stages in visual processing.

Observers often miss visual changes in the environment when they co-occur with other visual disruptions. This phenomenon is called change blindness. Previous research has shown that change blindness increases with age. The aim of the current study was to explore the role of post-perceptual stimulus processing in age differences. Therefore, the P3 component of the event-related potential was measured while younger, middle-aged, and older participants performed a change detection task under different task demands. Older adults detected fewer changes than younger adults, even when the task was very easy. Detected changes elicited greater P3 amplitudes than undetected changes in younger adults. This effect was reduced or even absent for middle-aged and older participants, irrespective of task demands. Because this P3 effect is supposed to reflect participants' confidence in change detection, less confidence in own responses may explain the decline of change detection performance in normal aging.