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These are excerpts and elaborations from my book "The Nature of Consciousness"
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The theory of emotion advanced by the British psychologist Edmund Rollsis based on the assumption that
the brain was designed to deal with reward and punishment. First, Rollsargues 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. Rollsdeals 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". Rollsargues 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 Rollspresumes is causing
consciousness. Consciousness is
therefore a property of the brain processing rewards, a side effect of
high-level planning. Rollsimplies 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. Back to the beginning of the chapter "Emotion" | Back to the index of all chapters |
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