I was an ultramarathoner for a number of years, qualified for the RAAM, etc. Robic's reaction is not typical for a competitor at those distances. Hundreds of ultramarathoners have completed the RAAM and other extreme events without losing their minds or the ability to think. He is enormously talented, but I think he plays up the "rabid dog" thing a bit to psych out his competitors.
I can tell you for a fact that disassociating to the degree he does will negatively impact most people's performance. Ultras are about navigating that knife-edge of mental focus - maintaining mindfulness without preoccupation with suffering. You cannot withdraw too far from the misery of your sitaution and still optimize your level of exertion over a period of days.
The best mindset is to consider the event a variant of kinhin, or walking meditation. The point of meditation is not to zone out!
Hallucinations during an event can be very interesting, though. My support crew has been sworn to secrecy.
