1. A common observation within visual search tasks, such as the one in this demonstration, is that the conjunctive absent condition takes about twice as long as the conjunctive present condition. Why would this be the case

Explanation: The conjunctive absent condition takes about twice as long as the conjunctive present condition. For the conjunctive searches, the rate of increase should be faster for target-absent searches than for target-present searches. The pattern of results for the conjunctive searches is consistent with the idea that attentional focus is moved around from shape to shape. Each focus on a shape takes time to judge whether it is the target or not. This explains why search time increases with the number of distractor shapes. If the target is found, the search stops. On the other hand, if the target is not present, you must search all the shapes. This explains why the target-absent trials take longer than the target-present trials. That means, if the target is found, then the search for the green circle stops. If the target is not present in the display, however, you have to search through all the shapes on the screen to make sure you have not missed the target.