Neuroscience, both the single-neuron probes and the amazing brain imaging by PET scans and functional MRI, allows us to see (though the pictures are still very blurry and far from the temporal and spatial resolution needed) what is happening in the brain as the mind thinks about various things.
It is unlikely that even the most detailed mapping of the brain will let us see how the brain
reasons and makes
decisions, but it may well show us the activity of the brain that underlies conscious awareness, so helping to solve the
problem of consciousness.
In particular, no observed brain event is ever likely to be unequivocally the result of a
chance event, or to be
uncaused by another physical or mental cause. Chance shows up statistically in observations of repeated identical trials. In the brain, it is impossible to set up perfectly reproducible identical initial conditions for experiments (which is a challenge even for physics).