Credit: Ann Thomson, Nature Neuroscience
Damage to the part of our frontal lobes just above our eyes, the orbitofrontal cortex, can damage our ability to subjectively determine the value of various choices. There are several clinical cases in which strokes or removal of tumors from this area have caused individuals to start making catastrophic personal choices, even while maintaining normal language, memory, intelligence and motor abilities. Padoa_Schioppa and Assad have now actually recorded from individual cells in this area in the monkey's brain while the monkey is making value choices (such as choosing between juices of different flavor, sweetness, or volume). They find that neurons in the orbitofrontal cortex encode the value of offered and chosen goods, independent of the location of the goods or the movements required to get them. In other areas of the brain value modulates choice relative to sensory or motor processes. Thus this part of the brain seems to be involved in assigning value, making economic choices between goods rather than choice between actions.