The inattentional blindness in soccer referees

BACKGROUND: Inattentional blindness is the inability to detect unexpected events occurring in the visual field of an individual. This phenomenon, which became famous after the experiments of Simon and Chabris (1999) on the invisible gorilla, has found little use so far in sport psychology. This study aims to verify whether soccer referees, in comparison to other participants, are more able to notice unexpected events, because they usually have to identify and cope with unexpected situations during matches. METHODS: The experiment involved referees, referees' observers, and university students. The participants were engaged in an attentional task which could have two levels of complexity: easy and difficult. RESULTS: The results show that referees have a superior capacity to identify unexpected events compared to the other participants. Although the referees were less experienced than referees' observers, they notice the unexpected event more frequently, regardless of the difficulty level of the task. CONCLUSIONS: Overall, the easier task led to a higher rate of identification of the unexpected event, but further studies are needed to improve the standardization of stimuli.