About the role the amygdala and orbitofrontal cortex might play in the conditioning process, Gottfried stressed the importance of the fact that this activity decreased only when the volunteers were shown images corresponding to the particular food they had eaten.
Thus, this sort of brain activity is likely involved with anticipating the enjoyment of a given food which also decreased after the volunteers had eaten until they didn't want any more. The volunteers' amygdala and orbitofrontal cortex responses remained the same for the smell (or corresponding picture) of the second food, which they did not eat.
Ultimately, this brain system may be far more versatile and wide-reaching than just a possible explanation for why food cravings can strike out of nowhere. It may be offer an adaptable system for learning, Gottfried said, that allows us to recognize cues that predict important events, and to discard cues that are no longer useful.
Contact: Christina Smith
American Association for the Advancement of Science