Emotionally arousing violent or erotic images have been known to cause momentary periods of blindness.
It has been demonstrated that there are limits to how much information people can hold in their visual short-term memory . As a consequence of this, we often miss visual images that pass right before our eyes when we are paying attention to something else.
But this is not all. The new research indicates that we can also miss what we are searching for if we are shown an unexpected image that impacts us emotionally, by a mechanism called "emotion-induced blindness".
In the experiment, research subjects were shown hundreds of pictures that included a mix of disturbing images along with landscape of architectural photos and were asked to search for a particular target image. An irrelevant, emotionally negative or neutral picture preceded the target by two to eight items.
The closer the negative pictures were to the target image, the more frequently the subject failed to spot the target. This suggests that emotionally arousing images impact attention in similar ways whether they are perceived as positive or negative.