Chapter 11: Emotions

Psychologists define emotion in terms of these components

- Cognition

- Action

- Feeling

- Physiological changes

These elements do not always stick together.

Emotions and Autonomic Arousal

Emotional situations arouse the autonomic nervous system.

Most situations evoke a combination of sympathetic and parasympathetic arousal.

Pure autonomic failure

Output from autonomic nervous system to body fails.

- People with this condition report feeling same emotions, but less intensely.

- People with damage to the right somatosensory cortex have typical

autonomic responses to emotional music but report little subjective

experience.

- Suggests that autonomic responses and subjective experience are not always closely connected.

Basic Emotions or Continuous Dimensions

- From a biological standpoint, much evidence favors dimensions.

Heart rate and breathing rate increase

with the intensity of an emotion:

- They do not distinguish fear from anger, or any other pair of emotions.

- You could not identify anyone's emotion by measuring autonomic activity

Brain Representations of Emotion

- Limbic system, located around the thalamus, is central to emotional processing.

- Disgust is the only emotion strongly tied to a specific brain region: the right temporal-parietal junction.

- remember insular cortex's role in flavor perception. (the primary site for taste processing and integrates multiple sensory inputs to create the perception of flavor)

- Emotions activate multiple areas of the cerebral cortex, not just one region.

- PET and fMRI evidence

- Findings support the idea that emotions exist along dimensions (e.g., pleasure vs displeasure, intensity, complexity) rather than as discrete categories.

Behavioral Activation System (BAS)

is associated with the left hemisphere (frontal and temporal lobes) and linked to approach behavior (happiness or anger).

Behavioral Inhibition System (BIS)

is associated with the right hemisphere (frontal and temporal lobes) and linked to inhibiting impulses and resolving conflict between drives.

- People with greater left frontal cortex activity tend to be happier and more

extraverted.

- People with greater right hemisphere activity are typically more withdrawn,

cautious, and prone to negative emotions.

Facial expressions are similar across cultures, supporting the idea of basic emotions.

- Blind individuals still show typical emotions expressions, suggesting they are innate.

- People can match expressions to emotions better than chance worldwide.

- But this may be overstated due to:

- Use of posed faces

- Forced-choice methods

- Better recognition of own-culture expressions.

Recognizing 6 facial expressions doesn't prove there are only 6 basic emotions.

- People identify expressions like contempt, pride, sleepiness, confusion, etc.

- Emotion recognition ability varies by individual:

- Young adults > older adults

- Women > men

- Psychopathic trait individuals perform worse than average.

- We rarely identify emotions from facial expressions alone:

- Body posture

The Functions of Emotion

- If we evolved the capacity to experience and express emotions, emotions must have served some adaptive function.

- Fear alerts us to escape from danger.

- Anger directs us to attack an offender.

- Disgust tells us to avoid something that might cause illness.

- The adaptive value of happiness, sadness, embarrassment, and other emotions is more speculative.

- Emotions provide a useful guide when we need to make a quick

decision.

Making important moral decisions

-We pay much attention to how the outcome will make us feel.

- Contemplating moral decisions activates the prefrontal cortex and

cingulate gyrus.

- People with strongest autonomic arousal least likely to make decision to

kill one person to save five others.

- Moral decisions are seldom made rationally.

- One decision or the other just "feels" right.

- We rationalize after decision has been made.

Moral decisions involve weighing utilitarian outcomes vs. emotional impact.

fMRI studies show:

-Different brain areas process utilitarian and emotional aspects separately.

- Ventromedial prefrontal cortex integrates both to guide decisions.

Prefrontal cortex damage leads to:

-Less emotional consideration in decisions

- Greater likelihood of choosing the utilitarian option (e.g., kill one to save

five)

Attack Behaviors

Attack and escape behaviors and corresponding emotions

(anger and fear)

- Closely related physiologically and behaviorally

- Attack behaviors depend on the individual and the situation.

- Example: hamster intruder

- Initial attack causes activity in the corticomedial area of the amygdala.

- Increases victim hamster's probability of attacking back when faced with subsequent attack. Up to 30 minutes or more.

Individual differences in aggressive, violent, or antisocial behavior depend on both heredity and environment.

Environment:

- An abusive childhood

- Witnessing violence between one's parents

- Living in a violent neighborhood

- Exposure to lead and other harmful chemicals

- Heavy use of alcohol or other drugs

Heredity

Twin studies indicate significant amount of heritability although there is some debate about experimental design.

- MAOA gene—low activity form shows a link to aggression

- There still seems to be a high interaction between genetics and the environment in which a person was raised.

Impulsiveness and aggressive behavior have been linked to low serotonin release.

Serotonin turnover:

- The amount of serotonin that neurons released, absorbed, and replaced

- Measured by the concentration of 5-HIAA in the cerebrospinal fluid

- Many studies use blood samples to measure the concentration.

Blood serotonin levels and brain serotonin levels don't correlate too well.

Serotonin Synapses and Aggressive Behavior

In mice, social isolation reduces serotonin turnover, especially in aggressive strains.

- Juvenile rodents have lower serotonin and show more fighting than adults.

- In humans, low serotonin turnover is linked to violent behavior, including arson and violent suicide.

- The serotonin-aggression link is small and not predictive at the individual level.