Getting a grip on visual search: Relating effort exertion to the control of attention.

Humans are generally biased to conserve energy, limiting the exertion of physical and mental effort. The need for attention to selectively process perceptual information is a ubiquitous part of mental life, but how mentally effortful is the process of finding the target of a visual search, and how much mental effort is required to focus attention in the face of potentially distracting stimuli? Does learning from demands on physical effort shape the control of attention, much like rewards and punishments? In this tutorial review, we provide an overview of a novel approach to probing the mental effort involved in visual search and the control of attention more generally. Situations are created in which exerting physical effort, via a hand dynamometer, can modify the demands of a visual search task. More specifically, participants can exert physical effort to reduce the putative mental effort required to find a target. When comparing across search conditions, this approach can reveal the conditions that participants are willing to physically work to achieve, with implications for the mental effort associated with these conditions. We also introduce a reciprocal approach in which demands on physical effort, and their association with the visual search task, are manipulated, providing an opportunity to examine how the control of attention is shaped by these effort demands. Some practical considerations for the implementation of these novel approaches are discussed, as are potential new research directions for which these approaches are well suited.