Researchers have noticed that during RSVP, if a second target object is presented 200 to 500 milliseconds (ms) after the first one, the brain often fails to pick it up. This impairment was first noticed in 1992.
Attentional blink has been a factor in the study of the human brain's ability to consciously perceive its surroundings and the stimuli contained within across space and time.
Theories Explaining Attentional Blink
Several theories have been proposed to explain attentional blink. Some of these are:
The Inhibition Theory
AB is produced by perceptual confusion between the first and second targets due to the target identification process. It is suggested that one way of eliminating confusion is to have items than cannot be named.
The Interference Theory
AB occurs because an inappropriate item is selected out of series because of competition (interference) among the multiple items in the series. It is suggested that the amount of interference increases with increasing size of the series and decreases with decreasing size of the series.
The Delay-of-Processing Theory
The AB deficit is said to arise from the decay of T2 when the person's cognitive processes are busy processing T1. It is suggested that anything that increases the difficulty of T1 processing will result in a greater AB deficit.
The Attentional Capacity Theory
The first target occupies attentional capacity to the detriment of a trailing secondary target. This theory suggests that the duration for which the first continues to occupy attentional capacity is related directly to the second one's processing difficulty.
The Two-Stage Processing Theory
It is proposed that rapidly processing a series of items requires two sequential stages: an initial rapid-detection stage (Stage 1) in which potential targets are detected, and a second capacity-limited stage in which items are processed serially for subsequent report. Access to Stage 2 is gained by items that have been identified as potential targets in Stage 1. And, until Stage 2 finishes processing T1, T2 cannot gain access to Stage 2. If T2 arrives in Stage 1 before Stage 2 is free, its access to Stage-2 processing is delayed. The AB deficit is brought about by the decay of T2 in Stage 1 during this delay. This theory suggests that the amount of AB will depend on the discriminability of T1. If Stage-2 processing of T1 is not slowed down by discriminability problems, processing of T2 is not delayed, and the AB deficit is reduced or eliminated.
Training improves recognition of quickly presented objects
So far it has seemed an irreparable limitation of human perception that we strain to perceive things in the very rapid succession of, say, less than half a second. Psychologists call this deficit "attentional blink." We'll notice that first car spinning out in our path, but maybe not register the one immediately beyond it. It turns out, we can learn to do better after all. In a new study researchers now based at Brown University overcame the blink with just a little bit of training that was never been tried before.
"Attention is a very important component of visual perception," said Takeo Watanabe, a professor in Brown's Department of Cognitive, Linguistic and Psychological Sciences. "One of the best ways to enhance our visual ability is to improve our attentional function."
Watanabe and his team were at Boston University when they performed experiments described in a paper published the week of July 9 in the Proceedings of the National Academy of Sciences. The bottom line of the research is that making the second target object a distinct color is enough to train people to switch their attention more quickly than they could before. After that, they can perceive a second target object presented as quickly as a fifth of a second later, even when it isn't distinctly colored.
