Emotions Matter
Here is a story that may have an emotional effect on you. Mother Superior calls all the nuns together
and says to them: “I must tell you all something. We have a case of gonorrhea in the convent.” “Thank
God,” says an elderly nun at the back of the room, “I'm so tired of chardonnay.” Most people react to
this joke with pleasurable surprise, including laughter. This chapter will try to explain the neural
basis of this and other emotional reactions that are integral to appreciating the meaning of life.
Here are some facts you probably didn't know. Tirana is the capital of Albania. Sarcoidosis is an
immune system disease characterized by small nodules in various organs. Flatworms lack endocrine
glands. If the rest of this chapter were so boring, you would probably stop reading soon. People
generally use perception and inference to acquire knowledge that matters to them, not just isolated
pieces of information that are irrelevant to their lives. But if you are excited about a trip to the
Balkans, or worried about a lump in your lymph nodes, or fascinated by invertebrate anatomy, then
you may well become interested in Albania, sarcoidosis, or flatworms. Emotions such as excitement
and worry shape our knowledge of reality by guiding us to acquire information that matters to us.
Although there are destructive emotions like deep depression that sometimes suck all meaning out of
people's lives, without emotion there would be no sense of what matters, and hence no wisdom.
This chapter describes brain mechanisms that constitute emotional feelings and thereby make
possible valued experiences, wisdom about what matters, and meaningful lives. Basic emotions like
happiness, sadness, fear, anger, disgust, and surprise can all be understood as brain processes, as can
more complex social emotions such as shame, guilt, contempt, envy, pride, and gratitude.
Psychologists and philosophers have long debated whether emotions should be understood as (1)
cognitive appraisals that people make about the degree of satisfaction of their goals, or (2)
perceptions of their physiological states. We will see how the brain can accomplish such appraisals
and perceptions simultaneously, dynamically integrating them with cognitive representations like
concepts and beliefs. Such integration is crucial for the accounts presented in subsequent chapters
about decision and action, what makes life worth living, and moral judgments.
People are often told to be rational instead of emotional. The view that emotions conflict with
reason goes back at least to Plato, who said that the intellect needs to control passions as a charioteer
controls a horse. There are indeed many ways in which emotional states can interfere with making
good inferences, ranging from psychiatric problems such as mania and depression to more everyday
afflictions such as wishful thinking, motivated inference, weakness of will, and self-deception.
Understanding emotional brain processes can help us to deal with these problems, but it can also help
us to appreciate how emotions are essential for effective thinking in all domains, from practical
decision making to scientific discovery.
Valuations in the Brain
The mind does not just have concepts and beliefs, but also attaches values to them. How do you feel
about the following kinds of things: babies, dogs, chocolate, beef, basketball, beer, television,
cockroaches, and broccoli? Your mental representations of many of these probably involve definite
emotional attitudes, positive or negative, although you may be indifferent to some of them. Different
facts about these things are also accompanied by emotional attitudes—for example, the positive
thought that chocolate tastes good and the negative thought that it can be fattening. When our brains
represent things using concepts and beliefs, they connect these representations with positive and
negative valuations.
Suppose, as the last two chapters argued, that your concept of chocolate is a pattern of activation in
a population of neurons. These neurons do not need to be confined to brain areas devoted to thinking
with words, but could also include neurons in areas for sensory processes such as sight, smell, and
taste. Hence the look, feel, and taste of chocolate are as much a part of your concept of chocolate as is
the verbal information that it is made out of cocoa beans. The activity of neurons in different regions
of the brain is temporally coordinated through the interactions that take place via synaptic
interconnections, produced by long axons that enable neurons in one part of the brain to excite or
inhibit neurons in other parts. Such multimodal activity makes it possible for you to recognize a
morsel as chocolate because it has the sensory properties, such as taste, smell, and mouth feel, of your
previous experiences of chocolate. For concepts and beliefs, similar kinds of coordination occur with
brain areas important for emotions.
There are many relevant brain areas, but I will focus on just two that are known to affect emotional
processes. First consider the amygdala, a small almond-shaped area located in the lower middle part
of the brain, below the cortex (figure 5.1). Recordings of neuron firings in animals and brain-scanning
experiments in humans show the amygdala is important for emotions, especially fear. For example,
when people are shown a picture of a scary face, brain scans show an increase of blood flow to the
amygdala, indicating that the neurons in it are firing more rapidly and need renourishing. Hence it is
plausible that the experience of being afraid of a gruesome face requires an association between the
firing of neurons that visually represent the face and the firing of neurons in the amygdala. We may
say or think that the face is scary, but this is only a verbal description of the emotional experience of
fear of the face. All mammals have an amygdala, and there are analogous regions in fish and reptiles.
The amygdala has reciprocal connections with many other brain areas, including the prefrontal cortex,
so that neural populations in the amygdala can increase the firing of neurons in the cortex, and vice
versa.
Another brain area important for emotions is the nucleus accumbens, located above the amygdala.
If you like eating chocolate, doing so probably increases activation in this region of your brain, which
has been extensively studied because of its role in addiction to drugs such as alcohol and cocaine.
Both of these drugs increase firing of neurons in the nucleus accumbens and related areas. Feelings of
pleasure and anticipation of desirable outcomes are associated with a circuit of neurons that employ
the neurotransmitter dopamine, running from the ventral tegmental area through the nucleus accumbens
to the prefrontal cortex. Such brain circuits are reciprocal, with many feedback loops. Hence for
people like me, who love chocolate, the pattern of neural firing associated with eating it includes
neurons in the nucleus accumbens as well as parts of the brain involved in verbal, visual, and other
sensory representations.
5.1 Location of the amygdala and some other brain areas important for emotion. Locations are only approximate because of the
difficulty of portraying the three-dimensional structure of the brain.
I won't try now to review all the brain regions that contribute to human emotions, a long list that
includes the orbitofrontal cortex (behind the eyes), the ventromedial (bottom middle) prefrontal
cortex, and the insula. More will be said below about how they work together to produce emotions.
The key point is that definite brain areas such as the nucleus accumbens and the amygdala are known
to be associated with positive and negative emotions, and such associations can be accomplished
through coordinated neural firings. The patterns of neural firing that constitute representations such as
concepts include the operations of neural populations in areas known to be involved in emotional
processing. Such associations ensure that when the brain is representing some aspects of the world, it
is simultaneously valuing it.
Cognitive Appraisal versus Bodily Perception
There is much more to emotion than just positive and negative valuation, as we see in the many
varieties of feelings, such as happiness, elation, contentedness, fear, anger, disgust, and horror.
Philosophers and psychologists have long debated the nature of the emotions, and their proposed
theories fall into two main camps: cognitive appraisal and bodily perception. According to cognitive
appraisal theories, emotions are judgments about the extent to which a perceived situation
accomplishes a person's goals. According to bodily perception theories, however, emotions are not
judgments but rather perceptions of physiological states. I will briefly review these historically
competing theories, and then offer a synthesis of them in the form of a model of how the brain
combines both cognitive appraisal and bodily perception.
When something happens to you, you naturally evaluate how it affects your life. When you get a
good job offer, it usually makes you happy because it contributes to your goals of having a successful
career and making money. According to the cognitive appraisal approach to emotions, a situation
makes you happy when it contributes to your goals, with greater contributions leading to greater
happiness. Sadness is the opposite, indicating that a situation impedes accomplishment of your goals,
as when you do not get a job you want or get a puny raise. Anger occurs when someone blocks the
accomplishment of your goals—for example, when a fellow worker keeps you from being successful
at your work. Fear arises in situations that threaten your survival goals, such as when a car cuts you
off on the freeway and almost makes you crash. Disgust is basically a violation of your eating goals
and desire for bodily integrity, as when someone tries to feed you something rep