Noticing of an unexpected event is affected by attentional set for expected action

In a study of the role of attentional set on noticing in an inattentional blindness (IB) paradigm, 86 college students (52 female) attempted to identify a target person on a prerecorded surveillance video. Participants received a folder containing information about a target person who either had a restraining order against him or was needed to attend to a family emergency, watched a surveillance video, and then answered questions about the video. In each video, 1 of 2 unexpected events (confrontation or person in a gorilla suit) was present. In the family emergency condition participants noticed the gorilla (71%) more often than the confrontation (33%). Those given the restraining order instructions noticed the confrontation (77%) more often than the gorilla (40%). Attentional set for expected actions can affect noticing in a complex, dynamic video. Although IB could not be implicated with certainty, findings are relevant to situations where IB may occur.