Blog reader Henry sent me the link to this clip from the BBC program Horizon of what is known as the McGurk effect, that shows that when the brain receives two different inputs, one aural and one visual, the brain forces you to register just one. Lawrence Rosenblum of the University of California, Riverside explains this effect and demonstrates how in this particular case the visual overrides the sound.

If we cannot do such a simple act of multitasking, imagine how unlikely it is that we can do more complex and challenging multitasking.