Abstract
Previous work has found that search principles derived from simple visual search tasks do not necessarily apply to more complex search tasks. Using a Multi-element Asynchronous Dynamic (MAD) visual search task, where high numbers of stimuli could either be moving, stationary and/or changing in luminance, Kunar and Watson (2011) found that, unlike previous work, participants missed a high number of targets, search for moving items was worse than for static, and there was no benefit to finding targets that showed a luminance onset. Here we investigate why luminance onsets did not capture attention and whether luminance onsets can ever capture attention in MAD search. In the current series of experiments, we found that there was still no search benefit for blinking targets even when stimuli showed abrupt rather than gradual luminance onsets – conditions known to produce attentional capture in simpler visual search tasks. Subsequent experiments showed that giving participants pre-exposure to the blinking cues and advance knowledge of what the target would look like did not produce efficient search for blinking targets. However, a single blinking target did capture attention in MAD search conditions. Further studies found that unique motion also captured attention but, in contrast to other work, unique static targets were not found efficiently. The results rule out a no capture hypothesis, a unique magnocellular hypothesis, and a unique item hypothesis and instead favour a unique feature hypothesis of attentional capture in complex search.
Meeting abstract presented at VSS 2013