David Eagleman Jonathan Downar Chapter Outline Early Theories of Emotion Core Limbic Structures Amygdala and Hypothalamus The Limbic Cortex and Emotions Limbic Association Cortex Modulation of Emotion ID: 634160
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13: Emotions
Cognitive Neuroscience
David Eagleman
Jonathan
DownarSlide2
Chapter Outline
Early Theories of Emotion
Core Limbic Structures: Amygdala and Hypothalamus
The Limbic Cortex and EmotionsLimbic Association Cortex: Modulation of EmotionNeurochemical Influences on Emotion
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Early Theories of Emotion
Emotional Expressions: Signposts on a Landscape of Inner States
The James-Lange Theory of Emotion: A Bottom-Up Theory
The Cannon-Bard Theory: A Top-Down TheoryTwo-Factor Theories: Reconciling Central and Peripheral Influences on Emotion
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Emotional Expressions
Emotions allow us to signal our internal state to others.
Animals have similar emotions to humans.
The study of human emotions goes back to Darwin, who suggested that emotions are constant across cultures and ages.Emotions include fear, anger, surprise, joy, sadness, and disgust.
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Emotional Expressions
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The James-Lange Theory of Emotion
According to this theory, the physiological reaction in the body causes the emotion.
Fight or flight system reacts very rapidly to stimuli.
This is a bottom-up theory because stimuli are detected by the peripheral nervous system and transmitted to the brain.
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The James-Lange Theory of Emotion
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The Cannon-Bard Theory
This arose as a criticism of the James-Lange theory.
Many bodily responses are too slow to generate an emotional response.
Artificially triggering sensations in the body does not induce emotions.This is a top-down theory, because information about the emotion spreads from the brain to the body.
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The Cannon-Bard Theory
This theory proposes that the thalamus relays sensory information to the cortex and to the hypothalamus.
The cortical pathway results in the perception of the emotion.
The hypothalamic pathway coordinates the emotional response within the body.
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Two-Factor Theories
Emotions do not need to be either top-down or bottom-up.
Emotions could involve some combination of both theories.
The two-factor theory was developed to address this.
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Two-Factor Theories
Schacter
and Singer’s experiment:
Subjects were injected with either saline or epinephrine to manipulate the physiology.Of those injected with epinephrine, half were told of the effects and half were not to affect the cognitive context.Subjects interacted with an actor.
Both physiology and cognition affected the subject’s emotional state.
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Two-Factor Theories
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Two-Factor Theories
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Core Limbic Structures: Amygdala and Hypothalamus
Hypothalamus: Internal States, Homeostatic Drives
Do Hypothalamic Circuits Generate Inner Emotional Experiences?
Amygdala: Externally Generated States and DrivesThe Amygdala and Emotional ExperienceHippocampus: Emotional Memories
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Core Limbic Structures: Amygdala and Hypothalamus
Ventral Striatum: Pleasure and Reward
Bringing It All Together: The Circuit of
Papez and the Ring of Limbic Cortex
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Hypothalamus: Internal States, Homeostatic Drives
The hypothalamus and the amygdala are important limbic structures.
The hypothalamus contains many different nuclei, which influence reproductive, appetitive, and agonistic behaviors.
Receptors in the bloodstream monitor the composition of the blood and report that to the hypothalamus.
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Hypothalamus: Internal States, Homeostatic Drives
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Hypothalamus: Internal States, Homeostatic Drives
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Hypothalamus: Internal States, Homeostatic Drives
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Hypothalamus: Internal States, Homeostatic Drives
The hypothalamus can affect the internal state via three pathways.
The autonomic output pathway stimulates the sympathetic and parasympathetic nervous systems.
The neuroendocrine pathway regulates hormone levels throughout the body.
The motivational pathway stimulates the forebrain to generate complex plans.
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Hypothalamus: Internal States, Homeostatic Drives
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Hypothalamic Circuits Generate
Inner Emotional Experiences
The hypothalamus is the first level of the nervous system that brings together
Survival-relevant stimuliInternal drives caused by these stimuli
A means to change the internal state to respond to the stimuli
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Amygdala: Externally Generated States and Drives
Much of the input to the amygdala is from the outside world.
Output from the amygdala
Down to the brainstem and spinal cordTo hypothalamic nuclei that are important for secreting hormones
Up to the striatum and the cortex
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Amygdala: Externally Generated States and Drives
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Amygdala: Externally Generated States and Drives
The basolateral amygdala tracks value and projects to the cortex.
The
centromedial amygdala projects to and influences the hypothalamus and brainstem.The amygdala is important for fear learning in classical conditioning experiments.
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Amygdala: Externally Generated States and Drives
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The Amygdala and Emotional Experience
Damage to the amygdala can impact behavior and emotions.
Monkeys with bilateral damage to the amygdala develop
Kluver-Bucy syndrome.In humans with damage to the bilateral amygdala, patients have difficulty learning and expressing fear.
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Hippocampus: Emotional Memories
The hippocampus can be functionally subdivided into the posterior and anterior hippocampus.
The posterior hippocampus is involved in spatial functions.
The anterior hippocampus is involved in emotional memory.
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Hippocampus: Emotional Memories
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Hippocampus: Emotional Memories
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Ventral Striatum: Pleasure and Reward
Electrical stimulation of the septal area, near the ventral striatum, provides intense reward.
Rats will push a lever to receive stimulation here to exclusion of all other activities.
This region shows increased activity during many rewarded behaviors.
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Ventral Striatum: Pleasure and Reward
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Ventral Striatum: Pleasure and Reward
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The Circuit of Papez
and the Ring of Limbic
Cortex
Circuit of PapezInterconnected areas involved in emotional responses.
Hypothalamus monitors the internal environment.
A
mygdala monitors the external environment.
Anterior hippocampus generates emotional states based on past experiences.
Ventral striatum represents reward value.
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The Circuit of Papez
and the Ring of Limbic
Cortex
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The Limbic Cortex and Emotions
The
Interoceptive
Insula: The “Feeling” Side of EmotionsCingulate Cortex: A Motor Cortex for the Limbic SystemVentromedial Prefontal
Cortex: A Generator of Gut Feelings
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The Interoceptive
Insula: The “Feeling” Side of
Emotions
The limbic regions are important for generating and modulating emotional states.The insula regulates the sensory, subjective experience of emotions.The insula produces whole-body sensations that are associated with emotional states.
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The Interoceptive
Insula: The “Feeling” Side of
Emotions
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The Interoceptive
Insula: The “Feeling” Side of
Emotions
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Cingulate Cortex: A Motor Cortex for the Limbic System
The cingulate cortex provides motor control for the autonomic nervous system, brainstem, amygdala, and hippocampus.
The cingulate gyrus contains many sub-regions, each of which influences different targets.
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
Iowa Gambling TaskSubjects pick cards from a risky deck of cards, with large gains and larger losses, for a safe deck, with smaller gains and losses.Over time, subjects learn that picking from the safe deck gives them more money.
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
Patients with damage to the ventromedial prefrontal cortex cannot get along well in daily life, despite normal intelligence.This structure uses somatic markers, gut feelings that suggest danger, to influence behaviors.Patients with damage to this area do not switch their behavior on the gambling task.
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
The ventromedial prefrontal cortex affects activity in the hypothalamus, anterior hippocampus, and brainstem.Through these connections, the ventromedial prefrontal cortex learns and generates visceral responses to stimuli.
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Ventromedial Prefontal
Cortex: A Generator of Gut
Feelings
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Limbic Association Cortex: Modulation of Emotion
The Mechanisms of Emotional Reappraisal
Brain Injury, Brain Stimulation, and Emotion Regulation
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The Mechanisms of Emotional Reappraisal
The adjustment of
emotional response based on
context is known as reappraisal.There are changes in the activity of the lateral prefrontal cortex and anterior insula when a subject reappraises the situation.There are also changes in connectivity between different regions during reappraisal.
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The Mechanisms of Emotional Reappraisal
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The Mechanisms of Emotional Reappraisal
In healthy subjects, the ventrolateral prefrontal cortex activates the ventromedial prefrontal cortex.
This reduces autonomic and amygdala responses to the stimulus.
In depressed patients, the ventromedial prefrontal cortex increases autonomic and amygdala responses to the stimuli.
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The Mechanisms of Emotional Reappraisal
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Brain Injury, Brain Stimulation, and Emotion Regulation
Brain injuries to the regions other than the prefrontal cortex seem to decrease the incidence of depression.
Dorsomedial prefrontal cortex injuries increased the incidence of depression.
Activity in other prefrontal areas has been shown to impact mood disorders in other studies.
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Brain Injury, Brain Stimulation, and Emotion Regulation
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Brain Injury, Brain Stimulation, and Emotion Regulation
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Neurochemical Influences on Emotion
Serotonin and Mood
Norepinephrine and Mood
GABA and Anxiety
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Serotonin and Mood
Serotonin plays an important role in regulating mood.
Subjects on a diet low in tryptophan, a precursor to serotonin, have a negative mood bias.
Subjects also change connectivity in the ventral striatum and ventromedial prefrontal cortex to resemble patients with depression.
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Serotonin and Mood
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Serotonin and Mood
Selective serotonin reuptake inhibitors (SSRIs) alter mood.
These are commonly used to treat depression.
Even low doses can remove the negative mood bias.Use of SSRIs improves confidence and cooperative behaviors.
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Serotonin and Mood
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Norepinephrine and Mood
Some antidepressant medications affect norepinephrine by blocking its reuptake into the presynaptic cell.
Effects of increasing norepinephrine are similar to increasing serotonin.
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Norepinephrine and Mood
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GABA and Anxiety
GABA is the most common inhibitory neurotransmitter in the brain.
Benzodiazepines increase the effect of GABA, thereby decreasing activity in the brain.
These can be used to decrease excitability, and therefore anxiety.
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GABA and Anxiety
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GABA and Anxiety
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