Theory number 3.

[Edwardo Piet]

Here's an idea: The whole is more than the some of its parts. A jigsaw puzzle with the pieces all fitted but jammed in the wrong holes is not the same as one fitted together perfectly. Perhaps, no single neuron is conscious but neurons working together equates to consciousness. And perhaps the more of them there are, the more complex they are and the more they work together the more conscious an organism is.