UBC Theses and Dissertations
Lifespan changes in covert attention alignment Brodeur, Darlene Adel
There are two ways that attentional resources can be aligned in visual space. They can be "pulled" automatically by stimulus cues, or "pushed" in a more strategic manner by the observer in response to information cues. The present study was designed to determine if the ability to align attention in these two ways changes throughout the course of the lifespan. Subjects (6, 8, 10, 23, and 73 years) were tested in two conditions. In the first, subjects were presented with a stimulus cue (a dot that appears briefly at a target location) prior to the presentation of a target. Attention was automatically aligned to a possible target location in response to the stimulus cue. In the second, an arrow was presented prior to the target, allowing the subject to align attention strategically in response to the cue. Cues were either valid or invalid predictors of target location, cue-target SOA was varied so the time course for the effective use of both types of cues was measured and compared. Eye movements were monitored to control for confounding developmental differences in vision. In a second experiment, lifespan changes in the interaction between the two forms of orienting were assessed by presenting subjects with both cues on each trial. The location information provided by each cue could be either compatible or incompatible with each other. The results of both experiments suggest that the ability to align attention automatically changes very little from early childhood through old age. Strategic attention alignment becomes more efficient in early adulthood. Children have difficulty sustaining attention at locations specified by information cues and seniors have difficulty using the information rapidly. Both children and seniors are less able to use information cues when stimulus cues are also available where as young adults can use both. These findings suggest that separate mechanisms are required to implement attention alignments to automatic and strategic cues.
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