Change blindness
[1] People's poor ability to detect changes has been argued to reflect fundamental limitations of human attention.
Change blindness has become a highly researched topic and some have argued that it may have important practical implications in areas such as eyewitness testimony and distractions while driving.
[2] Going back earlier, William James (1842–1910) was the first to mention the lack of ability to detect change in his book Principles of Psychology (1890).
[5] In the late 1980s, the first clear experimental demonstration was published showing very poor change detection in complex displays over brief intervals without eye movements being involved.
[2] With the rise of the ability to present complex, real-world images on a computer screen, McConkie, in the early 1990s, as part of new research at the new Beckman Institute for Advanced Science and Technology, renewed investigations of why the world looks stable and continuous despite the shifting retinal input signal that accompanied each saccade.
In the first experiment of this kind, in 1995, Blackmore et al. forced saccades by moving the image and making a change in the scene at the same time.
Individuals often take significantly longer to notice certain changes if there are a few small, high contrast shapes that are temporarily splattered over a picture.
This obstruction may impair an individual's ability to detect a change in their environment which could result in severe negative consequences while driving.
[18] As such, the inability to notice the bizarre nature of the dream has been coined as an example of change blindness, also known as individuals who are non-lucid dreamers.
Despite the mismatch, subjects gave responses that were comparable in emotionality, specificity, and certainty for faces they had or had not actually chosen.
[21] Further research has shown that the failure to detect mismatches between intention and outcome exists in consumer product choices[22] and in political attitudes.
[23] Prior research in the early part of the decade had shown that change blindness can be counteracted by a number of methods.
Shifting attention with a visual cue can help lower the negative effects of change blindness.
Direct comparison pairs the pre-change and post-change vibration intensities without a gap in between after a change has been missed to support the use of relative judgment rather than absolute.
[27] Chimpanzees similarly have difficulty with detecting change in flicker-type visual search after a blank display was shown.
This method mimics eye movements and can detect change blindness without introducing blank screens, masking stimuli or mudsplashes.
Mudsplashes are small, high contrast shapes that are scattered over an image, but do not cover the area of the picture in which the change occurs.
[12] A practical application of this paradigm is that dangerous stimuli in a scene may not be noticed if there are slight obstructions in an individual's visual field.
[12] Mudsplashes have not been used as frequently as the flicker or forced choice detection paradigms in change blindness research, but have yielded many significant and groundbreaking results.
The foreground-background segregation method for studying change blindness uses photographs of scenery with a distinct foreground and background.
When individuals detect a change, the neural networks of the parietal and right dorsolateral prefrontal lobe regions are strongly activated.
In addition, other structures such as the pulvinar, cerebellum, and inferior temporal gyrus also showed an increase in activation when individuals reported a change.
[33] It has been proposed that the parietal and frontal cortex along with the cerebellum and pulvinar might be used to direct an organism's attention to a change in the environment.
[33] Other studies using fMRI (functional magnetic resonance imaging) scanners have shown that when change is not consciously detected, there was a significant decrease in the dorsolateral prefrontal and parietal lobe regions.
In addition to fMRI studies, recent research has used transcranial magnetic stimulation (TMS) in order to inhibit areas of the brain while participants were instructed to try to detect the change between two images.
[34] The results show that when the posterior parietal cortex (PPC) is inhibited, individuals are significantly slower at detecting change.
A study in 2004 demonstrated that if the superior colliculus (responsible for eye movements) of a monkey's brain is electrically stimulated, there would be a significant decrease in reaction time to detect the change.
[61] In many cases, witnesses are rarely able to detect a change in the criminal's identity unless first intending to remember the incident in question.
[61] This inability to detect a change in identity can lead to inaccuracy in identifying criminals, mistaken eyewitness identification, and wrongful conviction.
[63] Research on the effects of change blindness while driving could provide insight into potential explanations of why car accidents occur.
