Visual Search for a Rare Target

Many real world search tasks require people to visually search for a target that only appears rarely. Imagine a doctor searching for a tumour in a mammogram or an airport security screener searching for a threat in a bag. In these tasks the target is typically infrequent. Recent work has suggested that when a target has a low prevalence people miss it 30% of the time (Wolfe, Horowitz & Kenner, 2005). Part of my research investigates why people fail to find a rare target and what can be done to improve target detection.

Related Publications

Rich, A. N., Kunar, M. A., Van Wert, M., Hidalgo-Sotelo, B., Horowitz, T. & Wolfe. J.M. (2008). Why do we miss rare targets? Exploring the boundaries of the low prevalence effect. Journal of Vision, 8(15, article 15), 1-17.

Distraction and Attention

Advancements in technology mean that people are able to do more tasks concurrently. But just because they can multi-task does not mean they should. Take the example of driving and talking on a mobile phone. Recent research has suggested that telephone conversations impair people’s driving ability (Strayer & Johnston, 2001). Why does talking on a mobile phone disrupt driving? Some of our work has shown that telephone conversations draw on cognitive resources leaving fewer available to attend the visual environment – one of the probable reasons why driving is impaired with phone use. Other work in my lab investigates how different types of distraction affect visual attention.

Related Publications

Kunar, M.A., Carter, R., Cohen, M. & Horowitz, T. (2008). Telephone Conversation Impairs Sustained Visual Attention Via A Central Bottleneck. Psychonomic Bulletin & Review, 15, 1135-1140.

Current Media Coverage

The Economist

Visual Search in a Repeated Environment

People often have to search a familiar environment. For example, you may regularly search the same coffee shop when looking for a friend for your weekly catch up. Part of my research investigates how people visually search a display that has been seen before. Previous work suggests that reaction times (RTs) to find a target decrease if it is in a display that has been seen before (Chun & Jiang, 1997). Although RTs decrease, we have shown that people do not guide their attention directly to the target position in a repeated display (Kunar et al., 2007), suggesting that search does not improve in a familiar environment. Instead other factors, such as response processes, may be facilitated when faced with a previously seen display.

Related Publications

Kunar, M.A., Flusberg, S.J., Horowitz, T.S., & Wolfe, J.M., (2007). Does contextual cueing guide the deployment of attention? Journal of Experimental Psychology: Human Perception and Performance, 33, 816-828.

Kunar, M.A., Flusberg, S.J., & Wolfe, J.M. (2008). The role of memory and restricted context in repeated visual search. Perception & Psychophysics, 70, 314-328.

Kunar, M.A., Flusberg, S.J., & Wolfe, J.M. (2008). Time to Guide: Evidence for Delayed Attentional Guidance in Contextual Cueing. Visual Cognition, 16, 804-825.