Moving Attention: Social and Nonsocial Attentional Orienting and Consequences of Shifts for Perception

Abstract

Our visual environment is incredibly complex. This complexity underscores the importance of visual spatial attention as a triaging mechanism for selecting the locations in our environment that are to receive preferential processing. Attentional resources are constantly deployed via shifts of attention across space, or attentional orienting; this orienting response occurs when someone we are speaking with averts their gaze, when a visually salient event occurs, and during countless other everyday events. In studying attentional orienting, two equally important lines of investigation are the factors that affect responsiveness to attentional cues, and how shifting attention alters perception of stimuli at the attended location. The aim of this thesis was to examine outstanding, yet important, questions about these two important aspects of attentional orienting, using the spatial cueing paradigm to manipulate visual spatial attention. The first part of this thesis examined factors that may affect responsiveness to attentional cues, with a specific focus on the orienting response triggered by social cues (e.g., gaze direction), and, at times, nonsocial cues (e.g., arrows). The first study in this section showed that orienting in response to gaze direction remains intact across levels of social anxiety, an individual-differences variable known to be associated with a range of attentional biases. The next study showed that a nonsocial motion signal equivalent in magnitude to a pupil shift is insufficient to elicit orienting, indicating that the social information contained in a dynamic gaze cue - which involves a pupil shift - is important for eliciting an orienting response. The final study in this section examined the efficiency of orienting by arrow cues, dynamic gaze cues, and static gaze cues, and found that while orienting by both types of gaze cues consistently survived a working memory load and therefore appears to be highly efficient, orienting by arrows was sometimes eliminated by a working memory load and therefore appears to be limited in its efficiency. Taken together, these findings speak to the robustness of the gaze-cueing effect, the importance of the social nature of the cue in generating the effect, and the remarkable efficiency of social orienting. The second part of this thesis examined two outstanding issues regarding the perceptual consequences of attentional orienting. In view of some research indicating that involuntary attentional shifts can harm temporal resolution (i.e., the ability to perceive fine temporal detail), the first study in this section examined whether the effect is a true attentional effect, or the outcome of perceptual conflict between the cue and target. The study found evidence to support the latter account, indicating that there is no true effect of involuntary attentional shifts on temporal resolution. The final study of this thesis examined the effects of attention on naturalistic ensemble processing, which involves the visual system pooling local detail to construct a global percept of a scene. The study found no effects of attentional shifts on this process, indicating that naturalistic ensemble processing is remarkably efficient. Together, these results clarify existing ambiguities concerning the effects of attention on important aspects of perception. Show more