I agree that we don't know enough to have a confident answer, but I find Scott Aaronson's question quite persuasive: if you were to replace brain cells with fun

I agree that we don't know enough to have a confident answer, but I find Scott Aaronson's question quite persuasive: if you were to replace brain cells with functionally-equivalent manufactured devices one cell at a time, is there a point at which the consciousness goes away?