Is attention location or object based? Give an example of a study (studies) that support either alternative.

Is attention location or object based? Give an example of a study (studies) that support either alternative.

Location based: Posner's general idea was to see if presenting a cue, indicating where a test stimulus might appear, enhances the processing of the test stimulus. The participants focused on a "+" in the middle of the screen and a cue was presented, e.g. in the upper-right corner. ( e.g. an arrow) It indicated where they were to shift their attention to (without moving their eyes - covert). The participant's task was then to press a button, as fast they could, when the stimulus appeared. The results showed that participants were faster in doing so when the cue was appropriate to the stimulus location. Posner interpretation was that information processing is more effective at the place where attention is directed.

Object-based: Egly's experiment required participants to focus on a "+" again, but added to rectangular objects to either side. Something like this:+

A.....C
...+
B

Whereby "C" is in one rectangle and "A" and "B" in one. He provided a cue close to "A" and then a stimulus was presented at either A, B, or C. He found that reaction times for "A" were the fastest, as this location was pre-cued. More important though, he found out that reaction times for "B" were faster than for "C". His interpretation was that the enhancing effect of attention (focusing on "A") had spread through the object (rectangle A-B) and therefore enhancement occured at "B" as well. --> Same object advantage

For static scenes, or scenes containing few objects, location-based visual attention appears appropriate. Whereas, in dynamic scenes, object-based attention can involve a mechanism that locks onto objects and follows them as they move.

To explain the results of Eglys experiment simpler one could say that participants where presented with the vertical rectangles of equal size, on to the right and one to the left. A que was presented signaling in which rectangle and in which part of it to expect the target (a darker box). The results show that of course reaction times were fastest when the target appeared in the same place where the cue had been presented. However, the reaction time was also faster when the target appeared in the same object but in a different part of it, although the distance to the other rectangle was equally long (so it cannot be explained as e result of location, since the distance is equally long). This shows that there is facilitation in reaction times through objects, visual attention in this case is said to be object based.