>>139719761. Dopamine sensitivity (sensitivity to reward prediction error)
2. Not really. The correct question is the meta-hard problem. (why do we think there is a hard problem)
4. It's a model of attention. It's useful to know what we are attending to and why, and to be able to predict what we should pay attention to next (free will).
From a physical standpoint,different brain regions compete for rewards by trying to predict how many rewards other regions will earn. If there is a large enough discrepancy between what was predicted and what was earned, this is called a reward prediction error, and this is what controls attention.
Attention means a particular part of the neural network is being updated in order to reduce the prediction error, so we won't be surprised again in the future. Since the brain doesn't have insight into it's own anatomy, the region being updated is represented "virtually", by something in the visual field, a sound, a smell, a thought, which then becomes the focus of our attention.
So we don't really have some non-physical otherworldy thing living in our heads that can't be explained, but it's useful to think and behave as if we do.
