The importance of being expert: Top-down attentional control in visual search with photographs

Abstract

Two observers looking at the same picture may not see the same thing. To avoid sensory overload, visual information is actively selected for further processing by bottom-up processes, originating within the visual image, and top-down processes, reflecting the motivation and past experiences of the observer. The latter processes could grant categories of significance to the observer a permanent attentional advantage. Nevertheless, evidence for a generalized top-down advantage for specific categories has been limited. In this study, bird and car experts searched for face, car, or bird photographs in a heterogeneous display of photographs of real objects. Bottom-up influences were ruled out by presenting both groups of experts with identical displays. Faces and targets of expertise had a clear advantage over novice targets, indicating a permanent top-down preference for favored categories. A novel type of analysis of reaction times over the visual field suggests that the advantage for expert objects is achieved by broader detection windows, allowing observers to scan greater parts of the visual field for the presence of favored targets during each fixation.

What is special about expertise? Visual expertise reveals the interactive nature of real-world object recognition

“…In experts, car targets were searched more efficiently relative to other objects, and the car search efficiency was highly correlated with the experts' level of car expertise. However, the car search slopes were steeper than in faces, indicating a relatively less efficient search (for similar results see Hershler and Hochstein, 2009). Thus, both categories of expertise impact the deployment of object-based attention, but in faces this process is involuntary and stimulusdriven (Hershler et al, 2010;Hershler and Hochstein, 2005) whereas in car expertise, the deployment of attention occurs in a voluntary top-down fashion.…”

“…This is an inherent concern when studying real world expertise, since the experts are selected based on their given skill level and there is no random assignment to the experimental conditions (Shen et al, 2014). For example, objects of expertise are more salient and engaging for the expert than for the novice (Golan et al, 2013;Hershler and Hochstein, 2009), and such enhanced engagement of the expert with objects from his domain of expertise may enhance the magnitude of response in FFA. Enhanced engagement may denote many observer-based factors, such as specific recognition goals, depth of processing, arousal, and in particular task-based attention, which has been shown to modulate FFA's magnitude of response (Reddy et al, 2007;Wojciulik et al, 1998).…”

Finding faces among faces: human faces are located more quickly and accurately than other primate and mammal faces

“…One possibility is that more efficient searches for human faces relative to animal faces may be due to the fact that expert objects, compared to non-expert objects, can be located in broader detection windows (i.e., peripheral detection advantage), allowing viewers to scan larger areas of their visual field during each fixation (Hershler & Hochstein, 2009; Hershler et al, 2010). Human faces may be distinct in some preattentive features (Lewis & Ellis, 2003).…”

Perceptual learning of parametric face categories leads to the integration of high-level class-based information but not to high-level pop-out

“…Still the neuronal effects could reliably be shown. Second, a recent study by Hershler and Hochstein (2009) tested car and bird experts for high-level pop-out. Despite years of training, pop-out was only visible for faces but not for target stimuli corresponding to their area of expertise (birds or cars).…”