Change detection
Ronald A Rensink2002, Annual Review of Psychology
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
Key Words change blindness, visual attention, scene perception, eye movements, visual memory s Abstract Five aspects of visual change detection are reviewed. The first concerns the concept of change itself, in particular the ways it differs from the related notions of motion and difference. The second involves the various methodological approaches that have been developed to study change detection; it is shown that under a variety of conditions observers are often unable to see large changes directly in their field of view. Next, it is argued that this "change blindness" indicates that focused attention is needed to detect change, and that this can help map out the nature of visual attention. The fourth aspect concerns how these results affect our understanding of visual perception-for example, the implication that a sparse, dynamic representation underlies much of our visual experience. Finally, a brief discussion is presented concerning the limits to our current understanding of change detection.
Key takeaways
- Another important distinction is that between the detection of dynamic change (i.e., seeing a change in progress) and the detection of completed change (i.e., seeing that something has changed).
- If the change is such that the overall appearance of the item is maintained (e.g., same overall size or shape), detection of the change is usually quite poor.
- If attention is needed for change detection, how does it operate?
- How might detection of dynamic change differ from detection of motion?
- As such, detection of completed change may differ from perception of difference only in the use of an additional process to establish that the structures being compared refer to the same external entity (see Change vs.
Related papers
Visual Attention and Change Detection
csjarchive.cogsci.rpi.edu
Studies suggest that visual attention, guided in part by features' visual salience, is necessary for change detection. An image processing algorithm was used for measuring the visual salience of the features of scenes, and participants' ability to detect changes made to high and low salience features was measured with a flicker paradigm while their eye movements were recorded. Changes to high salience features were fixated sooner, for shorter durations, and were detected faster and with higher accuracy than those made to ...
UC Merced Proceedings of the Annual Meeting of the Cognitive Science Society Title Visual Attention and Change Detection Publication Date Visual Attention and Change Detection
Studies suggest that visual attention, guided in part by features' visual salience, is necessary for change detection. An image processing algorithm was used for measuring the visual salience of the features of scenes, and participants' ability to detect changes made to high and low salience features was measured with a flicker paradigm while their eye movements were recorded. Changes to high salience features were fixated sooner, for shorter durations, and were detected faster and with higher accuracy than those made to low salience features. The implications of these results for visual attention and change detection research are discussed.
Change Blindness: Implications for the Nature of Visual Attention
Vision and Attention, 2001
In the not-too-distant past, vision was often said to involve three levels of processing: a low level concerned with descriptions of the geometric and photometric properties of the image, a high level concerned with abstract knowledge of the physical and semantic properties of the world, and a middle level concerned with anything not handled by the other two. 1 The negative definition of mid-level vision contained in this description reflected a rather large gap in our understanding of visual processing: How could the here-and-now descriptions of the low levels combine with the enduring knowledge of the high levels to produce our perception of the surrounding world?
To see or not to see: The need for attention to perceive changes in scenes
Psychological Science, 1997
When looking at a scene, observers feel that they see its entire structure in great detail and can immediately notice any changes in it. However, when brief blank fields are placed between alternating displays of an original and a modified scene, a striking failure of perception is induced: identification of changes becomes extremely difficult, even when changes are large and made repeatedly. Identification is much faster when a verbal cue is provided, showing that poor visibility is not the cause of this difficulty. Identification is also faster for objects mentioned in brief verbal descriptions of the scene. These results support the idea that observers never form a complete, detailed representation of their surroundings. In addition, results also indicate that attention is required to perceive change, and that in the absence of localized motion signals it is guided on the basis of high-level interest.
Visual search for change: A probe into the nature of attentional processing
Visual Cognition, 2000
A set of visual search experiments tested the proposal that focused attention is needed to detect change. Displays were arrays of rectangles, with the target being the item that continually changed its orientation or contrast polarity. Five aspects of performance were examined: linearity of response, processing time, capacity, selectivity, and memory trace. Detection of change was found to be a self-terminating process requiring a time that increased linearly with the number of items in the display. Capacity for orientation was found to be about five items, a value comparable to estimates of attentional capacity. Observers were able to filter out both static and dynamic variations in irrelevant properties. Analysis also indicated a memory for previously attended locations.
Partial Representations of Scenes in Change Blindness: In the Eyes and in the Hands
Abstract Change blindness is a person‟ s inability to notice changes in a visual scene that seem obvious when pointed out. Recent experiments using eye tracking techniques have suggested that even though participants do not detect a change they fixate on the changing area more. Two studies test whether this finding is present across different change blindness paradigms and whether it is detectable after fixation. In the first study we compare behavior in flicker and gradual change paradigms.
Change blindness theory and consequences
Current Directions in Psychological …, 2005
People often fail to notice large changes to visual scenes, a phenomenon now known as change blindness. The extent of change blindness in visual perception suggests limits on our capacity to encode, retain, and compare visual information from one glance to the next; our awareness of our visual surroundings is far more sparse than most people intuitively believe. These failures of awareness and the erroneous intuitions that often accompany them have both theoretical and practical ramifications. This article briefly summarizes the current state of research on change blindness and suggests future directions that promise to improve our understanding of scene perception and visual memory.
Change Blindness, Psychology of
Encyclopedia of Cognitive Science
Visual Salience in the Change Detection Paradigm: The Special Role of Object Onset
Journal of Experimental Psychology: Human Perception and Performance, 2004
The relative efficacy with which appearance of a new object orients visual attention was investigated. At issue is whether the visual system treats onset as being of particular importance or only 1 of a number of stimulus events equally likely to summon attention. Using the 1-shot change detection paradigm, the authors compared detectability of new objects with changes occurring at already present objectsluminance change, color change, and object offset. Results showed that appearance of a new object was less susceptible to change blindness than changes that old objects could undergo. The authors also investigated whether it is onset per se that leads to enhanced detectability or onset of an object representation. Results showed that the onset advantage was eliminated for onsets that did not correspond with the appearance of a new object. These findings suggest that the visual system is particularly sensitive to the onset of a new object. Over 100 years ago, Titchener (1901) stated that given the course of development as we know it, the organism must have attended to movement, etc., in its surroundings or have paid the penalty of inattention with its life. The moving, the new and the sudden are all possible-even probable-sources of danger. (p. 209
Related papers
Change Detection in a Change Blindness Flicker Paradigm
South African Journal of Psychology, 2004
This study explored trends in change detection within the change blindness (CB) flicker paradigm. A sample comprising 92 university students was tested for speed in change detection. A number of alternating photographic scenes with and without changes in objects were shown in a computer laboratory. There were significant differences between males and females for central and marginal interest changes on different change types, which included changes in colour, presence and location of objects. The results were used to illustrate the methodological restrictions of previous studies and to expand on theoretical explanations for this phenomenon. This study also challenged the various notions pertaining to the nature of the representations one forms when perceiving visually. The application of connectionist principles revealed the ambiguity of representational-based explanations for change detection.
On the applications of change blindness
Psychologia, 2008
An overview is presented of the ways that change blindness has been applied to the study of various issues in perception and cognition. Topics include mechanisms of change perception, allocation of attention, nonconscious perception, and cognitive beliefs. Recent work using change blindness to investigate these topics is surveyed, along with a brief discussion of some of the ways that these approaches may further develop over the next few years.
The development of change detection
Developmental Science, 2006
Changes to a scene often go unnoticed if the objects of the change are unattended, making change detection an index of where attention is focused during scene perception. We measured change detection in school-age children and young adults by repeatedly alternating two versions of an image. To provide an age-fair assessment we used a bimanual choice rather than open-ended verbal responses. The difference in detection speed and accuracy between 50-ms versus 250-ms blank screens between views indexed change detection in short-term visual memory independent of sensory and response processes. Younger children were significantly less efficient than older participants, especially when an object changed color or had a part deleted. Changes in object orientation were detected more readily. These results point to important differences in the perceptual reality of younger and older children.
Attentive and Pre-Attentive Processes in Change Detection and Identification
PLoS ONE, 2012
In studies of change blindness, observers often have the phenomenological impression that the blindness is overcome all at once, so that change detection, localization and identification apparently occur together. Three experiments are described that explore dissociations between these processes using a discrete trial procedure in which 2 visual frames are presented sequentially with no intervening inter-frame-interval. The results reveal that change detection and localization are essentially perfect under these conditions regardless of the number of elements in the display, which is consistent with the idea that change detection and localization are mediated by pre-attentive parallel processes. In contrast, identification accuracy for an item before it changes is generally poor, and is heavily dependent on the number of items displayed. Identification accuracy after a change is substantially better, but depends on the new item's duration. This suggests that the change captures attention, which substantially enhances the likelihood of correctly identifying the new item. However, the results also reveal a limited capacity to identify unattended items. Specifically, we provide evidence that strongly suggests that, at least under these conditions, observers were able to identify two items without focused attention. Our results further suggest that spatial pre-cues that attract attention to an item before the change occurs simply ensure that the cued item is one of the two whose identity is encoded.
Object presentations in change blindness
2003
2.. Attention and storage in working memory protects against change blindness AA crucial factor in change detection seems to be attention, a phenomenon discussed in BOX 1.. In the real world, changes almost always involve motion or luminance changes. This often evokess a visual transient that is unique, or very salient with respect to background noise, so that itt attracts attention (Phillips & Singer, 1974; Rensink, 2000b, 2002). Without a blank interval in thee change blindness paradigm, the unique transient makes the change easy to detect. With the
Mapping visual attention with change blindness: new directions for a new method
Cognitive Science, 2004
Change blindness provides a new technique for mapping visual attention with unprecedented spatial and temporal resolution. Change blindness can occur when a brief full‐field blank interferes with the detection of changes in a scene that occur during the blank. This interference can be overcome by attending to the location of a change. Because changes are detected at attended locations, but not at unattended locations, detection accuracy provides an indirect measure of the distribution of visual attention. The likelihood of detecting a new element in a scene provides a measure of the occurrence of attention at that element's location. Potential new directions, advantages, and problems with this method are considered.
Change blindness: past, present, and future
Trends in Cognitive Sciences, 2005
Change blindness is the striking failure to see large changes that normally would be noticed easily. Over the past decade this phenomenon has greatly contributed to our understanding of attention, perception, and even consciousness. The surprising extent of change blindness explains its broad appeal, but its counterintuitive nature has also engendered confusions about the kinds of inferences that legitimately follow from it. Here we discuss the legitimate and the erroneous inferences that have been drawn, and offer a set of requirements to help separate them. In doing so, we clarify the genuine contributions of change blindness research to our understanding of visual perception and awareness, and provide a glimpse of some ways in which change blindness might shape future research.
Sustained attention can create an (illusory) experience of seeing dynamic change
Visual Cognition, 2012
Perceptual conditions necessary to induce change blindness
Visual Cognition 10(2):233-255, 2003
Change blindness is a failure to detect a change in an scene when the change occurs along with some visual disturbances. Disturbances are thought to play a delocalizing role that affects the saliency of the “target” transient signal coming from the change location, which would otherwise capture attention and render the change visible. For instance, it is hypothesized that the appearance of new objects in the “mudsplashes” paradigm generates transient signals that compete with the target object's transient signal for attracting attention. Thus, experiments using the mudsplashes paradigm do not rule out a possible role of object changes in capturing attention. Here, by reversing image contrast polarity, we develop a new paradigm to produce change blindness when a real global transient signal is the only visual event occurring, with no edges added or deleted except in the target object. The results show that transient signals, per se, are able to prevent change detection. However, abrupt transients are not necessary if object change occurs in the zero-contrast phase of a smoothly fading and reappearing image, leaving attention as the only common factor affecting all cases of change blindness.
Attention, Fixation, and Change Blindness
The topic of this paper is the complex interaction between attention, fixation, and one species of change blindness. The two main interpretations of the target phenomenon are the 'blindness' interpretation and the 'inaccessibility' interpretation. These correspond to the sparse view (Dennett 1991; Tye, 2007) and the rich view (Dretske 2007; Block, 2007a, 2007b) of visual consciousness respectively. Here I focus on the debate between Fred Dretske and Michael Tye. Section 1 describes the target phenomenon and the dia-lectics it entails. Section 2 explains how attention and fixation weigh in these debates, and argues that Dretske's hyper-rich view fails precisely because he overlooks certain effects of attention and fixation. Section 3 explains why Tye's view is also unsatisfying, mainly because he misconceives the degree of access. Section 4 then puts forward the positive model covariance, which has it that the degree of cognitive access tracks the degree of phenom-enology, and contrasts it with Block's view on the Sperling iconic memory paradigm. The paper ends with a discussion of levels of seeing, which involve crowding, indexing, and other visual phenomena. Change 'blindness' is a set of phenomena that was discovered about two decades ago, yet an entirely satisfying understanding is still lacking. To move forward, a more detailed understanding of attention and fixation is called for.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.