''There's lots of unknowns regarding channelling. eg. Who or what is being accessed?''
The given information is assessed. Whether someone is able to provide information that they cannot possibly have acquired through normal means, or perhaps extrapolation based on trends, likelihood, probability, etc, which is not supernatural.
''the person is often in such an altered state that they have no awareness during the channelling and the info that is channelled material is unkown to them.''
Altered states of mind or consciousness is the work of the brain. Every state of mind or consciousness is related to brain state. To prove that, one only needs to try a psychedelic, LCD, etc.
The work and scope of the brain, capable of generating a mental representation of the external world, is far, far greater than what we experience consciously.
