but then it was countered by the natural kick-in of stimulation by a challenging visual approach.
A brain that is processing information at a reduced rate because it has been awake for many hours doesn't suddenly become able to process information faster because you're excited. You may start processing faster than you were ten minutes ago, but it is still slower than you would process if you were well rested.
It is all a matter of degrees.
If you had been awake for 200 hours would your processing rate be slow? Yes.
If you had been awake for 100 hours would your processing rate be slow? Yes.
If you had been awake for 50 hours would your processing rate be slow? Yes
If you had been awake for 25 hours..........
If you had been awake for 12.5 hours........
When does the answer become No Rat?