UBC Theses and Dissertations
Different attentional mechanisms subserve the attentional blink and visual search Ghorashi, S.M. Shahab
Joseph et al. (1997) found that a search task that was performed efficiently as a single task was impaired under dual-task conditions. This led to the claim that visual search is not performed preattentively. But that claim is questionable because different criteria (efficiency of visual search and mean level of performance) were used to assess attentional requirements under single- and dual-task conditions. In four experiments, I found that the two measures are affected in different ways by attentional manipulations and, therefore, represent different attentional processes. This finding questions the validity of the evidence used by Joseph et al. to substantiate the claim that all forms of visual search require attention.
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