Piero Scaruffi(Copyright © 2013 Piero Scaruffi | Legal restrictions )
These are excerpts and elaborations from my book "The Nature of Consciousness"
The theory of emotion advanced by the British psychologist Edmund Rolls is based on the assumption that the brain was designed to deal with reward and punishment.
First, Rolls argues that the brain determines which actions to carry out based on a reward and punishment mechanism. The brain is capable of computing the "value" (in terms of reward and punishment) of a sensory input. That capability comes from millennia of natural selection. For example, when the body needs food (translation: such and such a state of energy balance is insufficient), the brain generates the emotion of hunger. That motivates the body to eat. When the body has eaten enough (i.e. a proper state of energy balance has been recreated), the brain generates the emotion of satiety.
The whole brain (not just one region) is designed around the reward and punishment mechanism. The brain plans behavior that helps obtain rewards and avoid punishments, i.e. "motivated" behavior.
Rolls deals with emotions as "states produced by reinforcing stimuli" (a purely physical, neural approach).
The special role of "reinforcing" stimuli explains why only "some" stimuli elicit emotions. The ones that are "reinforcing" need to be decoded by special regions of the brain, which generate the neural processes that we call "emotions".
Rolls argues that there are different circuits for primary reinforcers (pain, touch and the smell of food) and secondary, or learned, reinforcers (the ones that become reinforced by association with a primary reinforcer, such as the sight of favorite food). The amygdala and regions of the cortex are involved in learning reinforcers and in decoding the known reinforcers.
Emotions have several functions, including: the production of an autonomic response (i.e., a faster heartbeat); the production of an endocrine response (i.e., adrenaline); the production of motivated behavior (not only specific to the event at hand but even a direction of behavior that will last a lifetime); a re-evaluation of the stimuli themselves for future use; communication to other members of the group; the storage of "important" memories.
The representation of a "reinforcer" (i.e., of an event that causes an emotion) contains information about how to calculate reward/punishment. Not surprisingly, the representation lends itself to generalization (if one tiger causes fear, all tigers should) and association.
The emotional aspect of a perception is basically due to the activation of its representation.
Patterns of neural activity in the brain correspond to patterns of stimuli in the world, i.e. to "objects". Therefore there exists a representation of an object in the brain, and such representation is the corresponding firing of neurons. Such a mental representation obtains its meaning in two ways: from the associated reward (or punishment) "value" and from its sensory-motor correspondence in the world. First, some actions are but the means to activate such representations, because living beings are programmed to achieve reward and avoid punishment, and their search for rewards (and away from punishments) is basically a quest for "activation" of those representations. A brain will work to make those representations become active. Secondly, each "object" is associated with the kind of actions that are possible and not possible with it. The same arguments apply to language: the word "banana" has meaning both because its taste has a reward value and because it is associated to the action of peeling.
The brain is designed around the mechanisms of reward and punishment. Whatever system is in charge of "action", that system must be taking the output of reward/punishment assessment as its goal: the brain as a whole wants to maximize rewards and minimize punishments, i.e. to maximize the activation of representations relative to “rewarders” and minimize activation of the representations relative to “punishers”. The specific behavior is not genetically fixed: what is fixed genetically is the goal, which is to maximize reward and minimize punishment.
There are two routes to action that can be followed in relation to reward. One route is shared by humans and other primates, so it is probably the most primitive one, and is centered on the amygdala. This route is a "shortcut" that sends stimuli directly to the motor system of the body. A second route involves "planning" the action, and therefore "thinking" about it, and centers on the language system. The second route is what allows us to make "long-term" decisions rather than only short-term decisions. It is also the one that Rolls presumes is causing consciousness. Consciousness is therefore a property of the brain processing rewards, a side effect of high-level planning.
Rolls implies that consciousness arises from the capability of thinking about one's thoughts, or higher-level thinking. He goes on to suggest that this feature could have an evolutionary value, as it allows people to correct mistakes of first-order thinking (in other words, to learn). Language is therefore necessary but not enough for consciousness: consciousness also requires the ability to think about thought, or higher-level thought.
Some sensory input becomes conscious (becomes "feeling") precisely because in this way it can be analyzed by higher-level thought. In a sense, the mechanism of higher-level thought would be useless if it could not use the feelings associated with sensory input.
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