You slightly misremembered the invisible gorilla test, a classical study about inattentional blindness. https://en.m.wikipedia.org/wiki/Inattentional_blindness

You slightly misremembered the invisible gorilla test, a classical study about inattentional blindness. https://en.m.wikipedia.org/wiki/Inattentional_blindness#Invisible_Gorilla_Test https://en.m.wikipedia.org/wiki/Inattentional_blindness#Invi... Somewhat fittingly "the basic Simons and Chabris study was reused on British television as a public safety advert designed to point out the potential dangers to cyclists caused by inattentional blindness in motorists."