Cognitive correlates of overt and covert attention in visual search

Human attention is an important cognitive resource to take into account when designing effective human-machine interaction and cognitive computing systems. Much of our knowledge about attention processing stems from search tasks that are usually framed around Treisman´s feature integration theory. However, search performance in these tasks has mainly been investigated using an overt attention paradigm. Covert attention on the other hand has hardly been investigated in this context. To gain a more thorough understanding of human attentional processing, we have experimentally compared search performance when people are instructed to either overtly or covertly search for targets under a variety of target/distractor combinations. The overt search results presented in this work agree well with the guided search studies by Wolfe et al. While response times are similar between the two attention conditions, we found that error rates are considerably higher in covert search.