I can't comment on the specific example of signing a form, but I did read about a case like this in Robert Sapolsky's "Why zebra's don't get ulcers".
It's a famous case in neurology, a man called "H.M."
Here's what's written in the chapter "Stress and memory" about H.M.:
"H.M." had a severe form of epilepsy that was entered in his hippocampus and was resistant to drug treatments available at that time. In a desperate move, a famous neurosurgeon removed a large part of H.M.'s hippocampus, along with much of the surrounding tissue. The seizures mostly abated, and in the aftermath, H.M. was left with a virtually complete inability to turn new short-term memories into long-term ones -- mentally utterly frozen in time.
Zillions of studies of H.M. have been carried out since, and it has slowly become apparent that despite this profound amnesia, H.M. can still learn how to do some things. Give him some mechanical puzzle to master day after day, and he learns to put it together at the same speed as anyone else, while steadfastly denying each time that he has ever seen it before. Hippocampus and explicit memory are shot; the rest of the brain is intact, as is his ability to acquire a procedural memory.
If you ask me, the CSI episode is definitely plausible if you consider that H.M. was real
It's a famous case in neurology, a man called "H.M."
Here's what's written in the chapter "Stress and memory" about H.M.:
If you ask me, the CSI episode is definitely plausible if you consider that H.M. was real