Emotion 1

Question 1

What are the components of emotional states?

Answer 1

Physiological responses, behavioral responses, perception, feelings/thoughts

Question 2

What stimuli elicit emotions?

Answer 2

Rewarding stimuli (S+), aversive stimuli (S-), omission of rewarding stimuli (⊘), termination of aversive stimuli (!)

Question 3

What brain regions are involved in emotion?

Answer 3

1. Meso-corticolimbic dopamine system: originates from the ventral tegmental area (TGA) in the midbrain, which sends dopaminergic projections to the forebrain, including the nucleus accumbens (NAc). Release of dopamine in the NAc is what signals rewards.

Amygdala, hippocampus, prefrontal cortex, hypothalamus

Question 4

What is the role of the amygdala in conditioned fear?

Answer 4

Lateral nucleus - associating neutral cues with aversive stimuli, Central nucleus - coordinating fear responses

Question 5

What conditioned fear responses are mediated by central amygdala outputs?

Answer 5

Freezing behavior, autonomic/physiological responses

Question 6

What is the role of the hippocampus in fear/anxiety?

Answer 6

Ventral hippocampus involved in conditioned freezing and innate anxiety

Question 7

What is the effect of lesions on the hippocampus?

Answer 7

Reduced innate anxiety in elevated plus maze (anxiolytic effect)

Question 8

What is the evidence for hippocampal role in human anxiety disorders?

Answer 8

Decreased hippocampal benzodiazepine receptor binding in panic disorder patients

Question 9

Where is the mesolimbic dopamine system located?

Answer 9

Ventral tegmental area (VTA), nucleus accumbens (NAc), involved in reward/positive emotion

Question 10

What is the advantage of using rat models?

Answer 10

Well-established behavioral tests, ability to target distinct brain regions

Question 11

What are the key brain regions in Papez’s theory?

Answer 11

Hippocampus, amygdala, hypothalamus

Question 12

What is Papez’s theory?

Answer 12

Papez’s theory, proposed in 1937, describes a neural circuit involved in emotion and memory called the Papez circuit. The key points are:
Papez Circuit
Starts in the hippocampus (subiculum region)
Travels through the fornix to the mammillary bodies
Then through the mammillothalamic tract to the anterior thalamic nucleus
Reaches the cingulate gyrus and entorhinal cortex
Returns to the hippocampus, forming a loop
Papez proposed this circuit as the anatomical basis for emotional experience and expression.

However, later research showed it plays a more significant role in memory functions like episodic and spatial memory.

Damage to structures in this circuit can lead to amnesia and memory impairment.

Question 13

What are the three components associated with rewards?

Answer 13

Wanting (feeling of desire), liking (feeling of pleasure), and approach behaviors.

Question 14

What is a potential mechanism underlying addiction?

Answer 14

Alterations in the brain substrates of reward-related processes.

Question 15

What are some classical techniques used to identify brain substrates of reward?

Answer 15

Intracranial self-stimulation, intracerebral microdialysis, intracranial drug self-administration, instrumental conditioning.

Question 16

What happens to nucleus accumbens dopamine levels when animals consume rewarding substances like food, drugs of abuse, or receive electrical stimulation of self-stimulation sites?

Answer 16

Nucleus accumbens dopamine levels increase.

Question 17

What was observed in human neuroimaging studies during reward anticipation?

Answer 17

Increased dopamine release (measured by raclopride displacement) in the nucleus accumbens.

Question 18

What are some inputs to the mesolimbic dopamine system implicated in reward processing?

Answer 18

Cholinergic projections from the pedunculopontine tegmental nucleus (PPTg) to the ventral tegmental area (VTA), and glutamatergic projections from the medial prefrontal cortex (mPFC) to the VTA.

Question 19

Is the increase in nucleus accumbens dopamine during rewarding stimuli consistent with the hypothesis that dopamine causes pleasure (liking)?

Answer 19

No, it is more consistent with the hypothesis that dopamine causes desire (wanting).

Question 20

How can researchers dissociate the brain substrates of “liking” from “wanting” in animal studies?

Answer 20

By measuring facial expressions (objective measure of liking) in response to rewarding/aversive tastes, and separating the effects of drug manipulations on liking vs. wanting behaviors.

Question 21

What brain region and neurotransmitter system have been implicated in the “liking” component of rewards?

Answer 21

The nucleus accumbens shell and opioid receptors.

Question 22

What evidence suggests an overlap between brain substrates of positive and negative emotions?

Answer 22

The nucleus accumbens, dopamine, and amygdala play roles in both reward-related and fear-related processes.

Question 23

What is the role of the vmPFC in emotion regulation?

Answer 23

The vmPFC plays a crucial role in regulating and inhibiting emotional responses. It helps control emotional reactions in social situations by integrating emotional information with plans and environmental cues

Question 24

How does vmPFC damage affect emotion regulation?

Answer 24

Damage to the vmPFC causes impairments in behavioral control and decision-making rooted in emotional dysregulation. Patients exhibit poorly regulated anger, frustration, lack of empathy, irresponsibility, and poor decision-making.

Question 25

Phineas Gage

Answer 25

Phineas Gage suffered bilateral vmPFC damage in an accident in 1848. He went from being “serious and industrious” to “childish, irresponsible, and thoughtless of others”, demonstrating the effects of vmPFC damage on personality and emotional control

Question 26

How does the vmPFC regulate fear and anxiety?

Answer 26

The vmPFC inhibits the amygdala, a key region for fear and anxiety responses. Stimulation of the vmPFC suppresses amygdala activity and reduces conditioned fear responses. Impaired vmPFC-amygdala connectivity is linked to anxiety disorders.

Question 27

Lateralization of vmPFC function

Answer 27

The left vmPFC governs parasympathetic activation, while the right vmPFC inhibits sympathetic nervous system activity during emotional processing. Right vmPFC damage impairs regulation of emotional responses to cognitive processes like empathy.

Question 28

Role of vmPFC in stress reactivity

Answer 28

The vmPFC is involved in determining if an environmental signal is perceived as a stressor. Its activity initially decreases with stress exposure but then increases during stress coping, suggesting a role in adaptive responses to stress

Question 29

What technique directly measures “liking” or pleasure in animals?

Answer 29

Measuring facial expressions and other objective responses to rewarding stimuli, distinct from just measuring approach/avoidance or “wanting”.

Question 30

What neurotransmitter system is critically involved in reward and motivation?

Answer 30

The mesolimbic dopamine system, including dopamine projections from the VTA to the nucleus accumbens

Question 31

Which brain regions are part of the brain’s reward circuitry?

Answer 31

Key regions include the nucleus accumbens, ventral tegmental area (VTA), prefrontal cortex, and pedunculopontine tegmental nucleus (PPTg).

Question 32

What happens when accumbal dopamine transmission is blocked?

Answer 32

Blockade of accumbal dopamine transmission blocks the behavioral effects of rewards.

Question 33

Which hypothesis is most consistent with the findings on nucleus accumbens dopamine and reward?

Answer 33

The hypothesis that nucleus accumbens dopamine causes “wanting” or desire for rewards, rather than directly causing the pleasure or “liking” of rewards