Watch the quick video below. First you’ll fixate on a small dot in the middle of the screen. Then you’ll get a visual cue which serves to direct your attention to a particular location. Simultaneously, four letter Os, each colored red or green, will appear. Your task is to say, as quickly as possible, the COLOR of the letter in the direction indicated by the cue.
Now try this one, same task, but with a different cue.
Much research on visual attention during the past 30 years has focused on the difference between these two types of cues — central arrows versus peripheral indicators such as the box you saw here. The idea was that responding to a cue in the center of your visual field was a different process from a cue placed precisely where the target object would appear. Responding to the first type of cue was voluntary, researchers argued, while the second type of cue was involuntary.
But there are many ways to direct a person’s visual attention, and a new experiment by Bradley Gibson and Alan Kingstone suggests that the distinction between voluntary and involuntary orienting is oversimplifying the process. Consider this new video, with a different type of cue (again your task is to say, as quickly as possible, the color of the letter in the direction indicated by the cue):
Now how about this one?
In one sense, using a word as a cue is just like the arrow in the first movie: arguably, responding to the word is a voluntary action, just like responding to the arrow. But when Gibson and Kingstone showed similar movies to volunteers and recorded their response times, a different pattern of results emerged. They presented four different types of cues — the words, arrows, and peripheral squares you’ve seen, as well as a central face which cued viewers by looking in the direction of the relevant letter. Here are their results:
Now the central / peripheral distinction doesn’t appear to be as important as whether the cue is a word or a symbol. What’s more, the type of word mattered, too. Viewers responded faster to the words “above” and “below” than “left” and “right.” For the other cues, there was no difference between left/right or up/down response times. Gibson and Kingstone claim that these results offer support for a new theoretical understanding of how attention can be cued. Instead of classifying cues as only voluntary or involuntary, they also classify them as “projective” or “deictic.” Words are projective cues because the observer must first establish a frame of reference before using the word to orient their attention. The arrows and other symbols are deictic — they orient the viewer directly to the relevant object.
One aspect of Gibson and Kingstone’s analysis doesn’t quite satisfy me. Wouldn’t it be simpler to argue that reading and understanding the words accounts for much, if not all of the difference in reaction time between word cues and symbolic cues? Is it possible to have a deictic word cue? Perhaps, if an experiment could be devised that compares projective and deictic uses of words, it could demonstrate whether the projective / deictic distinction is a useful one.
Gibson, B.S., & Kingstone, A. (2006). Visual attention and the semantics of space. Psychological Science, 17(7), 622-627.