Date: November 22, 1990

"One is not an immaterial soul, floating around in a machine."

— Sacks, Oliver (b. 1933)

Date: 1999

"As the brain gets more complex in the womb, then, like a dimmer switch, consciousness gradually grows and burgeons until, of course, in adulthood it reaches its particular pinnacles or depths."

— Greenfield, Susan (b. 1950)

Date: 1999

"On its own this trigger, as we can see from the earlier definition, is not going to generate consciousness. Imagine a candyfloss machine with a stick in the centre that then gathers more and more candyfloss as time goes on. Think of the epicentre as the stick in the centre, the burgeoning candy...

— Greenfield, Susan (b. 1950)