"As a brain researcher, I'd started out simply accepting the strictly objective principles of the behaviorist position. In the 1950s and early 1960s, all respectable neuroscientists thought in these terms. In those days, we wouldn't have been caught dead implying that consciousness or subjective experience can affect physical brain processing. My first break with this thinking — although I certainly didn't see it that way at the time — came in a 1952 discussion of mind-brain theory in which I proposed a fundamentally new way of looking at consciousness. In it, I suggested that when we focus consciously on an object — and create a mental image for example — it's not because the brain pattern is a copy or neural representation of the perceived object, but because the brain experiences a special kind of interaction with that object, preparing the brain to deal with it. I maintained that an identical feeling or thought on two separate occasions did not necessarily involve the identical nerve cells each time. Instead, it is the operational impact of the neural activity pattern as a whole that counts, and this depends on context — just as the word "lead" can mean different things, depending on the rest of the sentence."