Two Inattentional Blindness type experiments involving 446 participants were performed in order to examine how unexpected objects are noticed. Perception of these unexpected objects was measured using explicit and implicit measurements. Despite initial difficulty in determining implicit perception, results showed a dissociation between implicit measurements and explicit measurements, providing strong evidence for unconscious processing. Research into attention capture often emphasizes the role of either expectations or stimulus properties in attention capture; the current research examines both. Critical objects presented were either of a colour that participants were familiar with, or of a new colour. The different patterns of results for these two categories of objects provide evidence for two separate mechanisms of attention capture: a parallel process driven by the features of objects, and a serial process, driven by the intentions of the observer. Predications of the recent theoretical work produced by Most, Scholl, Clifford & Simons, (2005) are examined, and support is obtained for their theoretical formulation.

Two Inattentional Blindness type experiments involving 446 participants were performed in order to examine how unexpected objects are noticed. Perception of these unexpected objects was measured using explicit and implicit measurements. Despite initial difficulty in determining implicit perception, results showed a dissociation between implicit measurements and explicit measurements, providing strong evidence for unconscious processing. Research into attention capture often emphasizes the role of either expectations or stimulus properties in attention capture; the current research examines both. Critical objects presented were either of a colour that participants were familiar with, or of a new colour. The different patterns of results for these two categories of objects provide evidence for two separate mechanisms of attention capture: a parallel process driven by the features of objects, and a serial process, driven by the intentions of the observer. Predications of the recent theoretical work produced by Most, Scholl, Clifford & Simons, (2005) are examined, and support is obtained for their theoretical formulation.