This synapse would like a cheeseburger, please
According to Reuters, researchers at Harvard Medical School have found neurons responsible for choice:
The scientists, who reported the findings in the journal Nature, located the neurons in an area of the brain known as the orbitofrontal cortex (OFC) while studying macaque monkeys which had to choose between different flavors and quantities of juices.
They correlated the animals' choices with the activity of neurons in the OFC with the valued assigned to the different types of juices. Some neurons would be highly active when the monkeys selected three drops of grape juice, for example, or 10 drops of apple juice.
Other neurons encoded the value of only the orange juice or grape juice.
"The monkey's choice may be based on the activity of these neurons," said Padoa-Schioppa.
Earlier research involving the OFC showed that lesions in the area seem to have an association with eating disorders, compulsive gambling and unusual social behavior.
This seems to raise as many questions as it answers: what other types of choices are these neurons involved in? For example, is this population of cells just involved in food-related choices, or involved in expression of overall preferences, or simply in making comparisons? Are these neurons actually making the decisions, or are they sending some sort of "preference" value to another location that makes the decisions?
I imagine many of these are probably addressed in the Nature article. I'll try to make some time later in the week to look it over, but Magic Eight-Ball tell me "yeah, right, sucker."
I should also point out that this is made doubly interesting by the fact that I vaguely recall OFC playing an uncertain role in drug addiction. Of course, that may be more uncertain to me than to others. But this makes it clear that I have another structure I need to pay attention to in reference to reward and decision-making pathways... I suspect that as time approaches infinity, the number of structures I'll need to pay attention to similarly approaches infinity.
Wow, that's a lot of brain.