ignoring a number of black moving objects. The unexpected object in this case was a gray cross that moved horizontally across the display at various distances from the vertical midpoint (this was manipulated between participants). Overall, they found that inattentional blindness susceptibility increases with age, which replicates the finding from Graham and Burke. In fact, they found that every 10 years of age was associated with a 1.3 fold increase in the probability of displaying inattentional blindness. They also found that the probability of inattentional blindness increases as the distance between the observer's focus of attention and the unexpected object increases, which replicates the finding from Most and colleagues. However, they also found that the relationship that age has with inattentional blindness does not change as a function of the unexpected object's distance from the focus of attention, suggesting that useful field of view does not mediate the relationship between age and inattentional blindness. Similarity between stimuli A series of studies conducted to test how similarity can influence the perception of a present stimulus. In the study, they asked participants to fixate on a central point on a computer screen and count how many times either white or black letters bounced off the edges of the screen. The first 2 trials did not contain an unexpected event, but the third trial was the critical trial in which a cross that had the same dimensions as the letters and varied in colour (white/light gray/dark gray/black) moved from the right side of the screen to the left side and passed through the central point. The results revealed the following: during the critical event, the more similar the colour of the cross was to the colour of the attended letters, the more likely the participants were to perceive it, and the less similar the colour of the cross was to the attended colour decreased the likelihood of the cross being noticed. For the participants attending to the black letters, 94% perceived the black cross; 44% perceived the dark gray cross; 12% perceived the light gray cross, and only 6% perceived the white cross. Similarly, if the participant was attending to the white letters, they were more likely to notice the cross it was white (94%) than if it was light gray (75%), dark gray (56%), or black (0%). This study demonstrates that the more similar an unexpected object is to the attended object,