%0 Journal Article %T What Guides Visual Overt Attention under Natural Conditions? Past and Future Research %A Kai Kaspar %J ISRN Neuroscience %D 2013 %R 10.1155/2013/868491 %X In the last decade, overt attention under natural conditions became a prominent topic in neuroscientific and psychological research. In this context, one central question is ¡°what guides the direction of gaze on complex visual scenes?¡± In the present review recent research on bottom-up influences on overt attention is presented first. Against this background, strengths and limitations of the bottom-up approach are discussed and future directions in this field are outlined. In addition to that, the current scope on top-down factors in visual attention is enlarged by discussing the impact of emotions and motivational tendencies on viewing behavior. Overall, this review highlights how behavioral and neurophysiological research on overt attention can benefit from a broader scope on influential factors in visual attention. 1. Introduction Vision is the primary perceptual modality. Hence, visual information plays a key role in how we perceive the world and it constitutes the perceptual basis of our actions. The main task of the selection system is to choose the optimal location for the attention focus. This selection process is mediated by attention that bundles our limited cognitive resources and mediates an in-depth processing of environmental features at a given point in time [1, 2]. In this sense Posner [3] described the attentional focus in terms of a spotlight that scans the environment. In fact, the main task for the visual and oculomotor system is to direct one¡¯s gaze to the most important object in the visual field so that this object is projected to the fovea centralis providing sharp central vision. Given that the physiology of the human eye restricts the amount of relatively less noisy visual input at a certain point in time, one central question is ¡°what guides the direction of gaze?¡± In this context it has to be pointed out that we commonly differentiate between several definitions and components of visual attention; on the one hand, we speak of sustained attention when we describe our readiness to detect rarely and abrupt occurring signals over prolonged periods of time [4]. By contrast, our ability to attend to one visual signal of current importance while ignoring others is defined as selective attention [5]. Moreover, we can also divide our attention to different locations in the visual field even when locations are spatially separated [6, 7]. Different models have been proposed which incorporate these different components of attentional processes [8, 9] as well as further components such as an alerting system that is involved in preparing %U http://www.hindawi.com/journals/isrn.neuroscience/2013/868491/