Somatic marker hypothesis

Emotional experiences are categorized depending on their outcome. "Gut feelings" can arise when someone encounters a similar experience to that of a previous experience where either a good or bad outcome was categorized. Emotional experiences are tagged either as positive or negative depending on the outcome of the scenario and can signal when a person is in a similar situation. Good signals and bad signals increases the chance that you will repeat decisions that led to good outcomes and avoid decisions leading to bad outcomes. The signals also increase the speed of decision making as a person does not have to go through all possible outcomes of the situation, instead the signals are the dominant decision maker (the individual is unaware of this) leaving the person to really only rationalize the decision that they've already made. People that experience a breakdown of communication between past experience influencing present situations, due to injury, surgery, disease etc., have trouble making appropriate decisions. For example Damasio talks about a girl who experienced brain damage as a child which drastically influenced her behaviour into young adulthood, causing her to act inappropriate/abnormally and unable to experience guilt, shame, pride, sympathy etc., which would normally act as a guide to future experiences. She was not able to recall  or categorize past emotional experiences, and therefore her decisions were not influenced by these warning signals.