The Nature of Consciousness

Piero Scaruffi

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These are excerpts and elaborations from my book "The Nature of Consciousness"

Somatic markers

According to Damasio, the only thing that truly matters for an individualís emotional life is what goes on in the brain.The brain maintains a representation of what is going on in the body.A change in the environment may result in a change in the body.This is immediately reflected in the brain's representation of the body state.The brain also creates associations between body states and emotions.Finally, the brain makes decisions by using these associations, whether in conjunction or not with reasoning.

The brain evolved over millions of years for a purpose: it was advantageous to have an organ that could monitor, integrate and regulate all the other organs of the organism.The brain's original purpose was, therefore, to manage the wealth of signals that represent the state of the body (the "soma"), signals that come mainly from the inner organs and from muscles and skin.That function is still there, although the brain has evolved many other functions (in particular, for reasoning).Damasioidentified a region of the brain (in the right, "non-dominant" hemisphere) that could be the place where the representation of the body state is maintained. Damasio's experiments showed how, when that region is severely damaged (usually after a stroke), the person loses awareness of the left side of the body. The German neurologist Kurt Goldsteinhad already noticed in the 1930s that the consequence of right-hemisphere lesions is indifference.

The brain links a body change with the emotion that accompanies it.For example, the image of a tiger with the emotion of fear.By using both inputs, the brain constructs new representations that encode perceptual information and the body state that occurred soon afterwards.Eventually, the image of a tiger and the emotion of fear, as they keep occurring together, get linked in one brain event.The brain stores the association between the body state and the emotional reaction. That association is a "somatic marker".

Somatic markers are the repertory of emotions that we have acquired throughout our lives and that we use for our daily decisions.The somatic marker records emotional reactions to situations.Former emotional reactions to similar past situations is

what the brain uses to reduce the number of possible choices and rapidly select one course of action.There is an internal preference system in the brain that is inherently biased to seek pleasure and avoid pain.When a similar situation occurs again, an "automatic reaction" is triggered by the associated emotion: if the emotion is positive, like pleasure, then the reaction is to favor the situation; if the emotion is negative, like pain or fear, then the reaction is to avoid the situation.The somatic marker works as an alarm bell, either steering us away from choices that experience warns us against or steering us towards choices that experience makes us long for.When the decision is made, we do not necessarily recall the specific experiences that contributed to form the positive or negative feeling.

In philosophical terms, a somatic marker plays the role of both belief and desire.In biological terms, somatic markers help rank "qualitatively" a perception.

In other words, the brain is subject to a sort of "emotional conditioning".Once the brain has "learned" the emotion associated to a situation, that emotion will influence any future decision related to that situation.The brain areas that monitor body changes begin to respond automatically whenever a similar situation arises.

It is a popular belief that emotion must be constrained because it is irrational: too much emotion leads to "irrational" behavior.Instead, Damasiofound that a number of brain-damage cases in which a reduction in emotionality was the cause for "irrational" behavior.

Somatic markers help to make "rational" decisions, and help to make them quickly.Emotion, far from being a biological oddity, is actually an integral part of cognition.Reasoning and emotions are not separate: in fact, they cooperate.


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