The orbitofrontal cortex
Neurons that respond to the sight of food do so by learning to associate a visual stimulus with its taste. Because the taste is a reinforcer, this process is called stimulus-reinforcement association learning. Damage to the orbitofrontal cortex impairs this type of learning by, for example, altering food preferences. We know this because monkeys with such damage select and eat substances they would normally reject, including meat and non-food objects (Baylis & Gaffan, 1991; Butter, McDonald & Snyder, 1969). The functioning of this brain region could have critical implications for survival. In an evolutionary context, without this function of the orbitofrontal cortex, other animals might have consumed large quantities of poisonous foodstuffs and failed to learn which colours and smells signify nutritious foods. The orbitofrontal cortex is therefore important not only in representing whether a taste is rewarding, and so whether eating should occur, but also in learning about which (visual and olfactory) stimuli are actually foods (Rolls, 1996, 1999, 2000c).
Because of its reward-decoding function, and because emotions can be understood as states produced by rewards and punishers, the orbitofrontal cortex plays a very important role in emotion (Rolls, 1999).
Neurons that respond to the sight of food do so by learning to associate a visual stimulus with its taste. Because the taste is a reinforcer, this process is called stimulus-reinforcement association learning. Damage to the orbitofrontal cortex impairs this type of learning by, for example, altering food preferences. We know this because monkeys with such damage select and eat substances they would normally reject, including meat and non-food objects (Baylis & Gaffan, 1991; Butter, McDonald & Snyder, 1969). The functioning of this brain region could have critical implications for survival. In an evolutionary context, without this function of the orbitofrontal cortex, other animals might have consumed large quantities of poisonous foodstuffs and failed to learn which colours and smells signify nutritious foods. The orbitofrontal cortex is therefore important not only in representing whether a taste is rewarding, and so whether eating should occur, but also in learning about which (visual and olfactory) stimuli are actually foods (Rolls, 1996, 1999, 2000c).
Because of its reward-decoding function, and because emotions can be understood as states produced by rewards and punishers, the orbitofrontal cortex plays a very important role in emotion (Rolls, 1999).
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