UBC Theses and Dissertations
Setting attentional priorities : a comparison of the contributions of new objects and luminance changes Austen, Erin Leigh
New objects capture attention more reliably than sudden changes in features of existing objects. Item visibility may be responsible. In the present study, visibility of new objects and luminance changes was controlled by luminance contrast manipulations. In Experiment 1, search for new targets was faster than old targets, at all contrasts. This benefit for new targets was indexed by a search efficiency measure that served as a standard to evaluate other feature changes. In Experiment 2, the attentional effect of luminance changes in old items was measured. Luminance changes generally resulted in small search benefits, although polarity reversals led to larger benefits than changes in magnitude or contrast. Only a simultaneous polarity and contrast change captured attention as efficiently as a new object. It is suggested that new objects are assigned attentional priority; and old objects are treated as new when they undergo changes typically reserved for signaling new objects.
Item Citations and Data