Mind elsewhere

The notion that we can look, yet not see, because our attention is directed elsewhere, is well-established in psychology. Known as 'inattentional blindness', the phenomenon may explain why, one winter night in 1995, Boston police officer Kenny Conley ran straight past the brutal beating of an undercover officer by his colleagues. Colney was in pursuit of a suspect and claimed not to have seen the fight, but he wasn't believed and was convicted of perjury (later cleared on a technicality).

Now Christopher Chabris at Union College, New York and his colleagues - the same team behind the famous invisible gorilla experiment - have tested the plausibility of Colney's claim by recruiting dozens of participants and having them chase a researcher across campus whilst concurrently tasked with counting the number of times the researcher touched his head. At night, just seven of 20 participants (35 per cent) noticed a noisy fight involving three people that took place eight metres off the path. This proportion grew to 56 per cent in the day, but dropped back to 42 per cent (also in the day) when the counting task was made more demanding. 'These results demonstrate that under real-world conditions approximating those experienced by Kenny Conley, people can fail to notice a nearby fight,' Chabris and his colleagues said (Perception: tinyurl.com/6zwqbb9).