Date of this Version
Mills, M. (2016). Global/local processing in incidental perception of hierarchical structure. PhD diss., University of Nebraska.
The goal of the current thesis is to provide a framework for investigating and understanding visual processing of hierarchical structure (i.e., local parts nested in global wholes, such as trees nested in forests) under incidental processing conditions—that is, where processing of information at global and local levels is both uninformative (cannot aid task performance) and task-irrelevant (need not be processed to perform the task). To do so, a novel method combining two widely-used paradigms (spatial cueing and compound stimulus paradigms) is used for implicitly probing observers’ perceptual representations over the course of processing. This compound arrow cueing paradigm was used in five experiments to address a series of objectives. First, which level (global or local) is more dominant in the evolution of a percept? Relatedly, is the temporal structuring of global and local processing fixed or flexible? And what is the time course of level-specific advantages—do they occur earlier or later in the course of processing, and do they follow a transient or protracted time course? Finally, what controls level-specific selection (sensory, perceptual, and/or attentional factors)? The results of the five experiments addressing these issues contribute to a greater understanding of visual perception by elucidating the nature of global and local processing under incidental processing conditions.
Advisor: Michael D. Dodd