This idea of the spectator or observer has been quite common in popular thinking (folk psychology), and Dennett writes about it as the Cartesian theatre, which is quite witty. If you imagine reality as projected onto a cinema screen, then you are in the seat at the front, watching reality.
Of course, it's often been pointed out that this observer must have another observer, which detects it, and so on, infinitely.
Another problem is that the observer seems to float outside the brain; so where is it? For theists such as AB, this is not a problem, since he can just say, oh, it's the soul, therefore no description is required.
The biggest problem with it is that it seems to say that the first person stream of experience cannot be generated by the brain. But why not? Of course, neurologists and psychologists have not fully described how this works, and here is a nice gap, where AB can insert the soul, and then God.
But I suspect that answers will be found to this before long. Certainly, it's clear now that the brain does not just record sensory information, but constructs representations - this is why illusions and dreams are possible. See also research into change blindness.
