Motion-induced blindness (MIB; Bonneh, Cooperman, & Sagi, 2001) is a visual phenomenon in which salient, stationary high-contrast targets are perceived to disappear and reappear when viewed within a moving background mask. The present study examined the effects of depth ordering (three levels) and mask motion coherence (0%, 50%, and 100% coherence of the mask elements), as well as the interaction effects between these two variables, especially taking note of between-subject variation. It is clear that individuals experience different amounts of MIB, indexed using average, cumulative, and normalized measures. Other differences are exhibited in how depth order and levels of mask coherence affect individuals' perception of MIB. This study was able to partially replicate the depth ordering effects exhibited by Graf, Adams, and Lages (2002); however, we were unable to replicate the effects of mask coherence reported by Wells, Leber, and Sparrow (2011), and possible reasons are explored, including the possible role of adaptation. No significant interaction effect was found between depth order and coherence, suggesting these processes act independently of one another. Implications for between-subject variability are discussed. A single underlying parameter accounting for individual differences among observers was not identified, suggesting that normative models of MIB may not be practical.
