Editorial: Beyond Space-Based or Feature-Based Selection: Mechanisms of Object-Based Attention

Our senses are constantly bombarded by an overwhelming amount of information, yet, our brain has a limited computational capacity and can fully process only a small fraction of that information at any given time. By selectively attending to information we overcome this limited capacity, prioritizing the processing of behaviorally relevant sensory information to the detriment of behaviorally irrelevant sensory information. Mechanisms underlying attentional selection and the prioritization of select locations in space or select features, such as visual color or motion, have been investigated in considerable detail (e.g., Carrasco, 2011). Our perceptual experience, however, is not one of disjoint features at disparate spatial locations, but of unified representations, objects, which can serve as the goal of our actions. Relative to our understanding of space-and feature-based selection, much less is known regarding object-based selection (see Chen, 2012 for review). In object-based selection, the object is the unit of selection such that if one feature of an object is attended, other task irrelevant features of that object are also prioritized (e.g., Duncan, 1984; O'Craven et al., 1999). How object-based mechanisms might differ from other forms of feature-based selection is poorly understood. For example, in global feature-based attention, selecting a feature prioritizes processing of this feature across the visual field, irrespective of location (e. The definition of a perceptual object has long been the focus of both philosophical and empirical inquiry. Our ability to perceive visual objects is present from early in development (e.g., Spelke, 1990; Leslie et al., 1998 offers a comparison of the object concept in development and object-based attention). Our perception of objects is, in part, based on mechanisms of perceptual grouping, such as Gestalt principles, and attention can be, in turn, influenced by this grouping (e. One fundamental question is whether or not attention does automatically spread across all features and locations delineated by object boundaries. Given that the spreading of attention across an entire object may not always be optimal and may not be mandatory, another fundamental question is how subsets of an object might be prioritized and enhanced, while task-irrelevant subsets of an object might be suppressed. Whereas, some studies have considered a more " pure " form of object-based selection, trying to control for the confounds of space-or feature-based selection (e.g., Mitchell et al., 2003, 2004; Ciaramitaro et al., 2011), other studies have focused on how space-or feature-based selection are constrained by objecthood (e.