Document Type


Degree Name

Master of Science (MSc)




Faculty of Science

First Advisor

Elizabeth Olds

Advisor Role

Thesis Supervisor


What happens to visual selection if the features of objects in a scene are viewed incrementally rather than simultaneously? According to Olds et al. (2009), it depends upon which feature is presented first. Olds et al. (2009) used the feature-preview search paradigm to cue conjunction search items by presenting observers with a preview display that contained 1 of 2 features for all of the search items. Prior exposure to some features facilitated subsequent visual selection more than prior exposure to others; overall, size-preview offered the greatest search facilitation, followed by color-preview, and lastly, orientation-preview. Some feature-preview conditions, however, contained luminance transients, while others did not. In the present study, we equated relative differences in luminance onsets, across the different feature-preview conditions in order to determine whether or not feature-preview effects are mediated by luminance transients. The general pattern of results obtained by Olds et al. (2009) was replicated and different featurepreviews continued to have differential effects on subsequent search; relative differences in luminance transients did not mediate feature-preview effects. Alternative theories are proposed and discussed.

Convocation Year


Included in

Psychology Commons