Making Choices - How Your Brain Decides
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Your brain and decision-making
Source: Jeanette Norden, Understanding the Brain, 2007
The dichotomy of rational thinking and emotional behaviour prevailed in Western intellectual history until evidence provided by modern neuroscience established a new paradigm. The belief that reason and emotions were opposite and conflicting tendencies held morals to be the product of reason, and privileged reason as the foundation for decision-making. Emotion was viewed as a lower-level physical response associated with the body. Reason was associated with higher-level rational tendencies of the mind. Emotion and reason were antithetical.
Modern neuroscience has now established that truly rational behaviour is not possible without emotion, for emotion is essential for rational behaviour and plays a critical role in guiding our decision-making. "Emotions, and in humans the mental representation of emotions that are subjectively experienced as feelings, are absolutely necessary for rational behaviour" (Jeanette Norden, Understanding the Brain, 2007).
Areas of the brain associated with decision-making
Areas of the prefrontal cortex as well as areas of the limbic system are involved in executive function (which include concentration, impulse control, foresight, goal setting, and problem solving), and are associated with decision-making. However, these areas do not function separately or independently. Emotion, memory, and cognition are connected in complex ways, allowing our experiences, which influence and guide future decisions, to acquire meaning.
association areas of the cortex
Modern neuroscience subdivides the the cortex into sensory and motor areas, and association areas. In other words, the association areas of the cortex are those areas not specifically related to movement and sensory processes.
The cerebral cortex is the outer layer of the the brain, the dark outer layer in this image. The cortex is divided into the left and right brain hemispheres and appears wrinkled because it is compressed to fit into the skull.
The cerebral cortex is not a uniform structure, varying in thickness and evolutionary age. The neocortex is the most recently evolved cortex.
It is largely responsible for higher order brain functions, e.g., attention, emotions, memory, thought, language and consciousness.
prefrontal association cortex
The prefrontal association cortex is involved with executive functions such as concentration, impulse control, foresight, goal setting, and problem solving.
orbital frontal cortex
The orbital frontal cortex is part of the frontal lobe. It is located just behind the orbit of the eye. It is part of the limbic association area of the prefrontal cortex.
It is involved in our ability to abstract the mores of our culture and to apply them to our behaviour, a process relating to emotional experience, and not rational thinking.
limbic association cortex
The limbic system is currently conceived as a collection of structures that form the inner border ("limbus") of the cortex.
The limbic association cortex processes emotional information
Click here for more information on the limbic system.
The brain and moral decision-making
It used to be that moral behaviour was viewed as rational behaviour, the product of reason and entirely unrelated to emotion. The mores of a culture are historically created models that guide the behaviour of individuals within a group, often distinguishing one group of people from another. They may be explicit, implicit, reasoned, or taken for granted. When individuals don't live up to the moral code of their group, the often feel shame and guilt. When they do follow them, their brain's reward system is triggered and they feel good. This latter internal subjective state, or "feeling," will motivate and relate to future decisions.
These learned and shared models for living within a society are learned through socialization, beginning in infancy. According to Neuroscientist Jeanette Norden, "We don't decide on a moral code because we think about it." The orbitofrontal cortex is involved in abstracting the mores of our culture, particularly in the personal and social reals. Just as the brain abstracts the rules of language learned in early childhood, "the orbitofrontal cortex abstracts the rules of social interaction from the time we're born." We learn and follow the rules of our culture long before we learn to think about them. As adults we will tend to adhere to the habits of mind, values and behaviours of our formative environments unless we abstract the rules and decide to change our habits of thought.
Habits of mind underly decisions and actions that involve, e.g., stereotyping, racism, sexism, and Islamophobia.
Learning from moral psychology
The moral dilemma associated with a runaway train we well known. Individuals are asked to choose between two difficult options in different scenarios. Using fMRI, researchers study the brains of these individuals to determine what areas of the brain are active during the process of moral decision-making.
In the first scenario - a moral impersonal dilemma, individuals must decide whether to let five people die or whether to flip a switch to save those five, but causing one person to be killed. Most people across cultures, religions, and genders choose to flip the switch.
The second scenario - a moral personal dilemma, sets up a more active role for participants. The same five people will be killed by the runaway train. Individuals must now decide whether to let the five people die or whether to push the person standing next to them off the platform onto the track. Five people would be saved, but the person who was pushed will die. Most people across cultures, religions, and genders decided that would be wrong.
The fMRI images revealed that the most activated areas of the brain were the orbitofrontal cortex and other areas of the limbic system associated with learning, memory and emotion. Also, the limbic system was most activated when processing a moral personal dilemma. Experiments like these indicate that important decisions and judgements that we make implicate the emotional areas of our brain.
Reason and Emotion Guide Decision-making
In the article “Making Choices: How Your Brain Decides,” published in Time on September 4, 2012, Maia Szalavitz explains how “two distinct networks guide our reasoning and the behaviors we ultimately undertake based on those judgments.” One network is associated with cognitive control, and the other with value-based decision-making.
Szalavitz provides the following helpful insights:
“Understanding how the brain parcels out specific decision-making tasks can offer insight into conditions in which such networks go awry, such as in the case of psychiatric disorders. Depressed people, for example, clearly have difficulty with value-based decision making: because nothing feels good or seems appealing, all options appear equally bleak and making choices becomes impossible. Hoarding disorder, in contrast, may involve overvaluation of certain possessions and impairment of the cognitive control needed to shift one’s attention away from them. That explains why hoarding becomes more important than other life goals like maintaining relationships.”
Szalavitz also suggests that while studies using fMRI may identify exactly the areas of the prefrontal cortex and the limbic system involved in processing different stages of decision-making, “studies of brain lesions are better at helping scientists understand cause and effect than imaging studies alone: if a damaged region is linked with impairment on a particular cognitive test, you know that task requires involvement from that region; with imaging studies, however, researchers can never be sure whether brain activity in certain regions is crucial to the task at hand, or whether it resulted from extraneous factors like a participant being distracted in the scanner.”
Scientists do not rely on brain scans alone to understand the effects of traumatic brain injury on cognition and behaviour. They also study case histories and analyze data on hundreds of people to relate brain injury and lesions to cognitive impairment, behaviour dysfunctions, and other changes affecting brain functions related to cognition and emotion.
Effects of damage to decision-making areas of the brain
The following two case studies have been critical to our understanding of the role of emotions in making decisions. Although there are surface similarities in brain damage suffered by Phineas Gage and Elliot, neuroscientists have so far been unable to account for the significant differences between them in the personality changes caused by the damage to their brains.
Phineas Gage 1823-1860
The story of Phineas Gage
Posit Science - Brain Connection - The Strange Tale of Phineas Gage
UCLA Newsroom - UCLA researchers map damaged connections in Phineas Gage's brain - which begins with the following excerpt:
Poor Phineas Gage. In 1848, the supervisor for the Rutland and Burlington Railroad in Vermont was using a 13-pound, 3-foot-7-inch rod to pack blasting powder into a rock when he triggered an explosion that drove the rod through his left cheek and out of the top of his head. As reported at the time, the rod was later found, "smeared with blood and brains."
Miraculously, Gage lived, becoming the most famous case in the history of neuroscience — not only because he survived a horrific accident that led to the destruction of much of his left frontal lobe but also because of the injury's reported effects on his personality and behavior, which were said to be profound. Gage went from being an affable 25-year-old to one that was fitful, irreverent and profane. His friends and acquaintances said he was "no longer Gage."
The case of Elliot
Elliot's case history is more recent. He is a young man who developed a brain tumour that had to be surgically removed. The prefrontal cortex of both hemispheres was damaged, including axons beneath the prefrontal area, although there was more damage to the right hemisphere. His personality and his life changed dramatically. He could no longer experience feelings of emotion. He could remember emotions and describe the feelings, but he could no longer experience it.
His high IQ and his ability to reason were not affected. He could discuss the pros and cons of a situation, but he could not weigh the options. Consequently, he could not make a decision, especially when there were personal and social implications. Unable to engage his emotions, the feelings that would relate experience to reason and motivate Elliot to make a decision were lost to him following damage to his brain.
How rational are our decisions?
Dan Ariely makes a very persuasive argument that our decisions are predictably irrational/
Modern neuroscience has established that emotion plays an important role in cognition and behaviour. This new paradigm has replaced the mistaken dichotomy of rational thinking and emotional behaviour that prevailed for centuries. Learning, memory, experience, as well as and our feelings related to previous experience, influence decision-making and present action. "We learn from experience and decisions we make now influence our decisions in the future." We are not so much characterized by our ability to reason, as by the elaboration of the emotional experiences that guide our behaviour. (Jeanette Norden, 2007)
Daniel Ariely - TED Talk - Are we in control of our decisions
Los Angeles Times - Brain Implant Improves Decision-Making in Monkey
Posit Science - Brain Connection - The Strange Tale of Phineas Gage
UCLA Newsroom (includes video) - UCLA researchers map damaged connections in Phineas Gage's brain