Attentional Constraints On Tactile Perception
Attention constitutes a major determinant of the limitation on tactile perception in humans. To date, the majority of the tasks that were first formulated to study/highlight the attentional constraints on visual information processing have successfully been extended to the tactile modality: These include everything from tactile negative priming, through to tactile distractor congruency effects, and from tactile change blindness through to the tactile attentional blink. What is more, the majority of these attentional limitations on information processing in humans have now also been demonstrated in a cross-modal setting as well, primarily involving interactions between tactile and visual stimuli.
Change Blindness Due To Motion Change
For the experiment, six Gabor patches, arranged on a ring, moved as a unit down and then across in an L-shaped path. Along the path, one of the six Gabor patches rotated 15°. For half the trials, the rotation of a Gabor patch occurred at the juncture of the direction change . For the other half of the trials, a Gabor patch rotated along the horizontal axis . For the task, the participants simply indicated which one of the six Gabor patches rotated.
The purpose of the Control condition was to rule out motion itself as a cause for change blindness. In the first condition , the rotation of a Gabor patch occurs when there is both motion and a change in direction. In the second condition , there is only motion. If people are blind to the rotation in both scenarios, its quite possible motion itself induces change blindness as thats the commonality. Alternatively, if people have difficulty with the task only when the ring changes direction, its likely a change in motion direction elicits change blindness.
When the ring simply moved horizontally, people detected the change 86% of the time. However, a change in motion direction substantially reduced detection to 30%. These results suggest a change in motion direction triggers change blindness however, the authors noted that there could be an alternate explanation saccade-contingent change blindness.
Change Blindness Causes People To Ignore What Designers Expect Them To See
Summary: People often overlook new visual details added to an existing image. This change blindness can affect critical information such as error messages and navigation menus, leading to user confusion and task failure. Luckily, with the right visual presentation you can dramatically reduce the likelihood of change blindness.
Kathryn Whitenton
on 2015-03-29 March 29, 2015
Topics:
Our minds are amazingly quick and accurate at certain tasks, but consistently fail at others. Understanding what triggers success and failure is the key to creating effective interfaces. For example, studies have found that people fail to notice that the details of an image have changed.
Change blindness is the tendency of people to overlook alterations in images, especially when those changes appear immediately after a visual interruption such as a flickering screen.Two different factors play a big role in the likelihood of change blindness:
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Inattentional Blindness Or Inattentional Amnesia
Conclusions from studies of inattentional blindness are premised on the idea that a failure to report an unexpected stimulus results from a failure to see that stimulus. In principle, though, people might fail to report the unexpected stimulus even if they did see it they could simply forget that they saw it by the time they are asked about it. That is, they have inattentional amnesia rather than inattentional blindness . Differentiating these alternatives might be impossible because questioning inherently occurs after the event, leaving open the possibility of forgetting. Whether or not the inattentional amnesia explanation is more plausible or palatable is a matter of debate. For the amnesia account to hold, observers would have to consciously perceive the unexpected object and then forget that they saw it, something that might be less plausible when the unexpected object is particularly distinctive or unusual .
Change Blindness Is Normal
We are all tricked by change blindness in our everyday lives. Maybe you fail to notice someones haircut or that theyve changed into a new outfit. Maybe that magic trick really does look like magic. Change blindness isnt a bad thing, but its something to be aware of. Our minds dont always catch everything that happens in front of us.
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Change Blindness In Real
Our second finding was that there was no statistically significant difference between the mean levels of change blindness produced in real-world and on-screen viewing conditions. This means that altering both the format of display from the objects themselves to an on-screen virtual object representation, and the nature of the large visual transient from a camera pan to an eye saccade preceded and followed by VOR, did not significantly affect the rate of change detection in this experiment.
The possible interpretations of this finding are: that neither the format of display nor the nature of the large visual transient had a significant effect on change detection, that the format of display and nature of the large visual transient had equal and opposite effects on change detection, resulting in no combined effect overall, or that the similarities between the two conditions were so great compared to the differences, that any effects produced by either the format of display or the nature of the large visual transient were masked by the intrinsic design of the experiment.
Regarding the first part of the first interpretation, if the format of display had no significant effect on change detection, then this finding provides no support for our hypothesis, which was that the perceptual advantages of binocular stereoscopic vision would produce a greater rate of change detection in the real-world condition compared to the on-screen condition.
Inattentional Blindness Vs Change Blindness
In 1999, psychologists Chris Chabris and Dan Simons conducted what is now known as The Invisible Gorilla Experiment. In the experiment, participants watched a video of people passing basketballs back and forth. They were instructed to count how many times the basketballs were passed.
During the video, a person in a gorilla suit walked through the circle. But a shocking number of participants didnt notice the gorillas presence.
This experiment led to the creation of the term inattentional blindness. This term is often confused with change blindness. Lets go over the difference between these two phenomena.
Inattentional blindness is the failure to recognize visual objects when you are focused on something else. The participants were so focused on the people passing the basketballs that they failed to see the gorilla.
If the gorilla has always been in the environment, but participants failed to see the gorilla change fur colors or put on a shirt, then change blindness would have occurred.
Change blindness is the failure to notice changes to visual objects as they happen. During the change, you have recognized all of the visual objects that are in your environment. You just dont see when those objects have shifted, transformed, or changed entirely.
Inattentional blindness is caused by a sharp focus on something in your environment. Change blindness may be caused by a lack of focus or other factors.
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Change Blindness In Interface Design
In normal interactions with a UI, change blindness often occurs when a new element appears on the screen as a result of user action and other areas of the screen also change. The locus of the change is expected to be the visible design element that responds directly to the user action and the user moves the eyes in that direction yet in fact, the change is spread across multiple regions of the screen.
For example, when users tap on the hamburger menu in Aldikos Android app, they expect that the changes on the screen be related to that action namely, that the new elements will be localized in the area enclosing the menu contents. Their eyes will stay around that area and they will be unlikely to notice that the action-overflow button in the top right corner of the screen has been replaced with a search icon.
Aldiko for Android: When the menu is opened, the controls in the right top corner of the screen get replaced by a magnifier glass. The search tool will remain unnoticed because people will look at the expanded menu, which will be a direct result of their action they will expect the other elements of the screen to remain unchanged .Not only did Texas A & M University replace the search field with a search icon, but it also displayed the search text box far away from the search icon. The animation of the hero image was competing with the display of the search box.
Forced Choice Detection Paradigm
Individuals who are tested under the forced choice paradigm are only allowed to view the two pictures once before they make a choice. Both images are also shown for the same amount of time. The flicker paradigm and the forced choice detection paradigm are known as intentional change detection tasks, which means that the participants know they are trying to detect change. These studies have shown that even while participants are focusing their attention and searching for a change, the change may remain unnoticed.
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Why Change Blindness Happens To Us
If something in your visual field changed dramatically right before your eyes, you would notice it immediately, right? While you might think that you see or are aware of all the changes that happen in your immediate environment, there is simply too much information for your brain to fully process.
Your brain cannot be aware of every single thing that happens in the world around you. Big shifts can happen in your visual field and you are never even aware of these changes. Psychologists use the term change blindness to describe the tendency people have to miss changes in their immediate visual environment.
Here’s why change blindness happens as well as the effect it can have on how you perceive and interact with the world around you.
Affective Processing Of Unconscious And Unattended Stimuli
Evidence from affective blindsight further corroborates the notion that affective properties of a visual stimulus can be partly computed in the brain even when the subject is not conscious of the stimulus. Extensive damage to the primary visual area of the cerebral cortex may leave a patient phenomenally blind over part or all of their visual field. Nonetheless, when forced to guess about some property of a visual stimulus presented in their blind field for example, Is the line segment vertical or horizontal? such patients may make inspired guesses, a phenomenon known as blindsight for example, correctly guessing the orientation of the unseen line segment far over 50% of the time. Recently, some cases of affective blindsight have been reported. When images of emotionally expressive faces are presented to these patients’ blind fields, they are sometimes nonetheless able to guess, with high accuracy, the affective valence of the faces. Neuroimaging studies of these patients have associated their inspired guesses about the image’s affective properties with changes in amygdala activity. Parallel findings have emerged from neuroimaging studies of normal subjects, with higher amygdala activation upon exposure to emotionally charged and especially to fearful faces, even when these faces are not consciously perceived.
Stephen D. Christman, in, 2018
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What Is The Relationship Between Different Change Detection Paradigms
The CB parameter was significantly positively related to CE percentage correct, r = 0.42, P = 0.001. The faster the detection rate in the CB task, the more continuity errors participants noticed in the video clips. This result suggests that the ability to notice visual changes is relatively stable over different stimulus sets . This finding indicates that change detection performance in the standard flicker CB task can be generalized to more ecologically valid displays.
Driver Capability And Overconfidence
Overconfidence in ones ability has been found in a variety of domains from academic study and financial decision-making to driving ability . Indeed, in one study 7090% of drivers reported that their driving was better and less risky than that of the average driver . Similarly, participants usually overestimate their ability to detect changes in a visual scene. When participants were asked whether they would see certain changes within a scene, they stated confidently that they would. However, when other participants were tested via a change blindness technique, the actual detection rate for those changes was low . Although it does not appear possible to teach participants to see changes more efficiently , it is possible that by increasing awareness of visual limitations, people will be more vigilant overall and perhaps more likely to avoid engaging in distracting tasks.
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Error Messages And Status Notifications
Error messages, not surprisingly, are commonly affected by change blindness. The user has just submitted a form, the screen blinks, and 99% of the page looks exactly the same, with only the addition of a single new element. The Goodsourcing.com example below shows an error message that is vital: the Data Transfer Error notification, which informs the user that the required Job Title field has been left blank. But this information is easily overlooked, because the visual presentation blends in with the rest of the page.
The Data Transfer Error notification on this GoodSourcing.com registration form is added to the existing content when the page reloads, but can be easily overlooked due to change blindness.
Progress indicators, or other status messages that help users understand what is going on with a system, are another frequently overlooked item, because they are small visual elements added to an existing display. Even an animated progress indicator like the white circle in the middle of the Southwest Airlines application can be overlooked if it isnt distinguishable from the rest of the screen.
Left: The white animated progress indicator on the Southwest airlines app is almost impossible to distinguish even though it is placed in the exact center of the screen. Right: A similar progress indicator on Kayak.com is noticeable because it includes a contrasting background element to distinguish it from the background of the application.
The Reliability Of Drivers Self
It is well known that self-report data can be subject to biases such as participants being untruthful in their responses and answering in such a way as to conform to social expectations . However, self-report questionnaires are nevertheless a useful tool for the assessment of interventions and participant attitude change that can be very difficult to measure effectively in other ways. In addition, there is a precedent for the validity of self-report data in the driving domain. Lajunen and Summala asked two groups of peopleapplicants to a driver instructor training course and students on the courseto fill in the Driver Behavior Questionnaire and a scale designed to measure the extent to which participants were trying to give socially desirable answers. The applicants completed the questionnaires in public and the students completed them in private. There were few differences between the two groups but those who completed the questionnaires in public reported negative behaviors less frequently. Overall, the DBQ responses showed only a relatively small bias toward socially desirable responding.
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The Magic Of Change Blindness
Estimated reading time: 7 minutes
Magicians are generous to researchers. Not only do their tricks inspire scientific questions, but those tricks also provide spellbinding demonstrations to hook and interest kids and adults alike. Inspiration and fascination cant be underestimated. They open doors to career paths, hobbies, areas of study, and more. And researchers have recognized well the magic of magicians. Within the last few decades, researchers have studied magicians books and tricks , done the research , and . One of the latest published research articles on magic involves a magicians trick, change blindness, and eye tracking.
Factors That Might Influence The Effectiveness Of Change Blindness Demonstrations
In an attempt to be as effective as possible, the change blindness images were all of driving-related situations . They were also designed to cover a range of perceived difficulties so that some demonstrations contained obvious changes that participants would expect to notice easily but were, in reality, difficult to detect. Overall, participants were surprised by how challenging the changes were to see and stated that it was more difficult to observe the changes than they had originally thought. One might argue whether it was the driving-related stimuli or the surprising difficulty of the change blindness intervention that shifted peoples self-ratings. However, given that the same results did not occur in the visual search task or in the difficult questions task, we believe these factors were not responsible for the results. In any case, it would seem sensible to construct change blindness tasks using content that relates as closely as possible to the relevant context/domain of education to be targeted so that participants can more easily see the applicability of the demonstration.
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What Is Change Blindness
Basically, it is when something we are looking at changes without us noticing. But how can it happen? We all like to think that we have a keen eye for whats going on around us. We are natural observers. People watchers. We see things. We notice stuff. If something has changed, we can tell.
Well, actually, thats not quite true. Studies show that if we are distracted for long enough, then our focus fails. Even more surprisingly, the change can be huge and we still wont see it. So how does it happen?
Change blindness is a failure to detect that an object has moved or disappeared and is the opposite of change detection. Eysenck and Keane