Thursday, July 28, 2005
Researchers studied a patient, B., who lost his amygdala, hippocampus, the nearby temporal cortices, and his insula to a herpes infection. B. has a 40 second memory span, and (among I'm sure quite a few other disabilities) cannot name familiar foods by taste or smell.
He does, however, have an unconscious preference for sweet drinks over salty ones. This is incredibly interesting. I'm not shocked that perception of nutritiveness (sweet=calories=good to eat) would be separate from like-dislike decisions or complicated taste perceptions, but that that most basic function is the one preserved in the higher brain. The limbic area, which B. largely lacks, is generally most responsible for primal functions, and other areas handle complicated matters like consciousness and preference. This is the kind of study I love to see. Brains are so cool!