No expert, but the way I remember it from the book, it's one idea how an evolutionary path towards consciousness might start. First it's just a nerve-path to p

No expert, but the way I remember it from the book, it's one idea how an evolutionary path towards consciousness might start. First it's just a nerve-path to prevent flinching back from the contact with something you wanted to manipulate. But once you have a fancy neural path that tells the visual cortex what light/objects to expect after you move your head left/right (maybe flee if it's unexpected), it's only a small evolutionary step to re-purpose this path, "execute" the same path while suppressing the head movement. So now you can process further what you are expecting if you move left vs right. Which could be interpreted as a step towards being conscious of your surroundings. (This is not 100% what the book says, but the idea I got from that chapter.)