"A scientist was going to" joke

A scientist was going to do experiments on the functions
of the brain. So after gathering three volunteers, he decided
to see what would happen when he removed the left half of the
brain from the first man. After doing the operation he put
the man into a rowing machine who proceeded to row and count:
"one...three...five...seven..."
He wrote down the results and decided to see the effects
of removing the right side of the brain on his second volunteer.
After the operation he put the second man in the rowing machine
and he counted while he rowed: two...four...six...eight.
Finally, the scientist wanted to see what would happen
if he removed the entire brain. After doing so on the third
volunteer, he put him in the rowing machine and the patient
counted: uno...dos...tres...quatro...