Abstract
Our recent work has revealed that the breadth (spatial extent) of attention influences the effective capacity of visual sensory (iconic) memory (Gmeindl, Jefferies, & Yantis, submitted). Here, we examine whether the breadth of attention might influence even the earliest substage of visual sensory memory, known as visible persistence. It has long been known that briefly presented stimuli remain momentarily visible even after they have physically disappeared. There is evidence that the transient orienting of attention reduces the temporal precision of visual processing (Yeshurun & Levy, 2003), which may reflect an attentional modulation of visible persistence (Visser & Enns, 2001), but there has been no systematic investigation of the relationship between the breadth of attention and visible persistence. In the current study, we manipulated the breadth of attention during a task that assesses the duration of visible persistence (Di Lollo, 1980). Twelve dots from a 5 x 5 matrix were presented in each of two successive displays separated by a blank inter-stimulus interval (ISI), which was varied systematically between 8 and 48 ms. Observers were to indicate which dot was missing from the 5 x 5 matrix. The two displays could be temporally integrated and the missing dot accurately identified if the duration of visible persistence exceeded the duration of the blank ISI. The deployment of a narrow focus of attention increased the duration of visible persistence relative to a broad focus of attention. Our findings dovetail with previous evidence that focal attention modulates the spatial resolution, contrast sensitivity, and temporal resolution of visual processing. These results suggest that one way in which the breadth of attention modulates the effective capacity of visual sensory memory is by influencing the duration of visible persistence.
Meeting abstract presented at VSS 2012