Intrusive Effects of Task Irrelevant Semantic Information on Visual Selective Attention

George Washington University, Washington DC

Investigators

Abstract

Selective attention involves the remarkable ability to dynamically search for and select information from the environment that is relevant for the current goal. How the human cognitive system achieves this is a fundamental question in cognitive science. Given that what humans consciously perceive will, ultimately, depend on where attention is directed, understanding attentional mechanisms is an important first step toward revealing the neural mechanisms that support conscious awareness. It has long been established that physical features, such as spatial location or object appearance, can guide attentional selection in a spatial task. These researchers will examine the extent to which attention can be inadvertently grabbed by a visual item that is irrelevant to the spatial-orienting task at hand if that item happens to be semantically related to something recently experienced. The research team will investigate hypotheses regarding the underlying mechanism by which this type of attentional intrusion occurs during the process of trying to visually locate something. To further understanding of the basic mechanism, the research team will also use neuroimaging to examine at what neural stage in the visual system this intrusion effect takes place. Understanding what grabs visual attention and why could have important practical applications, such as better designing dynamic, interactive visual displays on devices such as tablets, smart phones, or computers. The proposed research project aims to test a set of novel predictions regarding the influence of high-level properties of a scene to attentional selection. A major goal is to rigorously test the hypothesis that task-irrelevant semantic information constrains attentional selection by directly acting on space- and object-based representations: task-irrelevant objects that semantically relate to something seen recently are more likely to be attended. Predictions will be tested using real-world scenes, and by utilizing real-world objects. In addition to the rigorous behavioral experiments aimed at understanding the mechanism by which task-irrelevant but semantically primed stimuli exert their intrusive effects on attention, the researchers will use neuroimaging methodology to examine hypotheses regarding at what stage in the human visual system the effects occur.