Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness

by Peter Godfrey-Smith

But how could something as mundane as an efference copy system give rise to something so powerful? The mere existence of bits of language floating about inside us ought not to have so many consequences. Part of the explanation may lie in the way that sentences of inner speech can be attended to. They are made available to much of the brain in something like the same way that ordinary speech is. Indeed, the similarities are so strong that it’s easy for people to mistake sounds that exist only in their auditory imagination for sounds they are actually hearing. In an experiment done in 2001, people were told to listen to featureless random noise through a set of headphones, and were told that the song “White Christmas” might occasionally be played very quietly through the noise. They had to press a button if they were sure they’d heard the song. About a third of the subjects pressed the button at least once, but in fact the song was never played. The usual interpretation of the experiment is that the subjects in the experiment imagined the tune they were supposed to listen for, and sometimes mistook their own auditory image for a genuine playing of the song. The sounds we cook up in our heads, including the sounds of words, are broadcast in our minds in something like the way that many ordinary perceptual experiences are broadcast.