Chapter 14: Emotion and Stress

Question 1

What is an Emotion?

Answer 1

Emotions are subjective experiences that arise spontaneously and unconsciously in response to internal and external events.

Physiological response and conscious feeling.

Question 2

Expression & Recognition of Emotion

Answer 2

Arousal
Approach / Avoidance
Communication

The Yerkes-Dodson Law

Question 3

The Yerkes-Dodson Law

Answer 3

The Yerkes–Dodson law is an empirical relationship between arousal and performance, originally developed by psychologists Robert M. Yerkes and John Dillingham Dodson in 1908. The law dictates that performance increases with physiological or mental arousal, but only up to a point.

The graph of Arousal Level (y) vs. Performance (x) is bell-shaped.

Question 4

Facial Expressions

Answer 4

Facial nerves control the muscles involved in facial expression.

–Cranial nerve VII: superficial muscles attached to skin
–Cranial nerve V: deep muscles attached to bones of head

Question 5

Facial nuclei

Answer 5

–Located in pons nuclei near midline.
–Upper 1/3 of face receives bilateral input.
–Lower 2/3 of face receives contralateral input only.
–Hemispheric stroke may impact muscle tone in lower face on one side.

Question 6

Neural Control of Facial Expression

Answer 6

Right Hemisphere Cortical Damage.

Voluntary smile: sideways
Spontaneous: normal

Volitional facial paralysis

Two pathways control expression:

• Voluntary: motor cortex input
• Involuntary: subcortical (BG)

Question 7

Neural Control of Facial Expression:

Parkinson’s Disease

Answer 7

Parkinson’s disease

Emotional facial paralysis
Two pathways control expression
- Voluntary: motor cortex input
- Involuntary: subcortical Basal Ganglia

Question 8

Emotions are Universal

Answer 8

Paul Ekman: small number of universal emotions.

• Happiness, sadness, anger, fear, disgust, surprise.
• Expressed by 42 facial muscles.

Children’s capacity for emotional expression:
Blind infants express emotions (e.g. social smile) at the same time as sighted infants
Infants protest separation from mothers at the same time across cultures

Question 9

Cultural Contributions to Expression

Answer 9

Cultures influence how expressive we are in group situations.

–American students are about as expressive when alone as when in a group of strangers
–Japanese students are more expressive when alone than when in a group of strangers

Question 10

Individual Differences in Emotion

Answer 10

Kagan: Temperament differs at birth.
–Babies that are highly reactive to environmental stimuli may develop anxiety disorders later in life
–Low responders may develop antisocial behaviors later in life

Psychopaths are extremely non-responsive, possibly leading to lack of empathy;
Low amygdala activation.

Question 11

Three Theories of Emotion

Answer 11

–James-Lange Theory
–Cannon-Bard Theory
–Schacter-Singer Theory

Question 12

James-Lange Theory

Answer 12

Specific pattern of autonomic arousal (bodily response) leads to specific conscious emotion.

Emotion can be induced by the corresponding bodily responses

Question 13

Schacter-Singer Theory

Answer 13

Physiological arousal contributes to emotion’s intensity, while identity of emotion is based on cognitive appraisal.

Subjects injected with adrenaline or placebo:
–In absence of “appropriate explanation” for arousal participants manipulated into emotional experience
–Informed vs. ignorant subjects paired with euphoric or irritable companion
–Ignorant subjects attributed physiological arousal to presence of companion.

This theory has the most support right now.

Question 14

Complexity of Emotion

Answer 14

Physiological feedback may not be necessary, but adds intensity.
–Patients with spinal cord injury have full range of emotions, though muted.

Conscious appraisal may not be necessary, but allows for identification of appropriate response
–Disgust vs. pride

Question 15

Biological Correlates of Emotion

Answer 15

Complex interacting physical responses that combine activation of ANS, amygdala, cingulate cortex, and cerebral cortex

Question 16

The Limbic System

Answer 16

that combine activation of ANS, amygdala, cingulate cortex, and cerebral cortex

Cingulate Cortex
Corpus Callosum
Thalamus
Hippocampus
Amygdala
Hypothalamus

Question 17

The Amygdala

Answer 17

Stimulation: produces fear & anxiety

Damage: difficulty identifying fear & anger expressions
Input: sensory cortices, ACC, hippocampus

Output: frontal & temporal lobes, BG, hypothalamus

Question 18

Kluver-Bucy Syndrome

Answer 18

bilateral temporalobectomy.

• Decreased emotional reactivity
• Hyper-orality: putting random things in mouth
• Hyper-sexuality

Question 19

The Amygdala

Answer 19

Stimulation: produces fear & anxiety

Damage: difficulty identifying fear & anger expressions
Input: sensory cortices, ACC, hippocampus

Output: frontal & temporal lobes, BG, hypothalamus

Imaging: more active when viewing expressions of fear.

Bilateral damage to the amygdala impairs ability to associate neutral and aversive stimuli.

Question 20

Fear Conditioning

Answer 20

Information related to CS and US can enter amygdala directly through thalamus or indirectly through cortex
Lateral Nucleus (La): site of CS-US association
Central Nucleus (Ce): expression of CR

Question 21

Anterior Cingulate Cortex

Answer 21

Role in emotion, attention, cognitive processing, consciousness.
–Serves as gateway between limbic structures and PFC
–Active when we express emotion
–Damage may be implicated in psychopathy
–Same regions activated by physical and emotional pain
–Right ACC larger in people who score high in harm avoidance

Question 22

The Cerebral Cortex

Answer 22

Clinical observations of frontal lobe damage—e.g., Phineas Gage

• Difficulty making and executing plans
• Reduced emotionally, esp. fear and anxiety

Question 23

Emotional lateralization of The Cerebral Cortex

Answer 23

• Left hemisphere damage: depression
• Right hemisphere damage: surprisingly cheerful

Look left, right hemisphere processes emotional facial expression better and faster.

Question 24

Stress

Answer 24

unpleasant and disruptive state resulting from the perception of danger or threat

Question 25

Stressors

Answer 25

sources of stress, can be physical or psychological

Question 26

General Adaptation Syndrome (GAS)

Answer 26

1. Alarm Stage: The stressor upsets homeostasis or cellular balance.
2. Resistance Stage: The Body fights back by adjusting to the stress.
3. Exhaustion Stage: Rest permits enhanced adaption.
   No Rest= overtraining, injury, lack of adaption

Dome-Shaped Graph of the Stages

Question 27

Two major systems mediate most components of the stress response

Answer 27

SNS activation raises Catelcholamines.

HPA activation raises Cortisol.

Question 28

Stress Hormones

Answer 28

Sympathetic Nervous System:
1. Norepinephrine (Noradrenaline)
2.  Epinephrine (adrenaline)
–Increase output from heart
–Liberate glucose from muscles for additional energy

Hypothalamic Pituitary Axis:
Cortisol
–Increases energy by converting proteins to glucose, increasing fat availability, and increasing metabolism
–Long-term energy increase for sustained stress

Question 29

Sympathetic Nervous System (SNS)

Answer 29

Walter Cannon (1929):
–Stressors lead to SNS activation
–Adrenal medulla releases 2 Catecholamines: adrenaline and noradrenaline
–The resulting increases in heart rate, blood flow, and respiration rate help the person deal with the stressful situation

Question 30

Hypothalamic-Pituitary-Adrenal (HPA) Axis

Answer 30

Higher cognitive centers identify specific stimulus as a stressor.
Sensory information also travels to the amygdala, which identifies danger.
The amygdala sends information to the hypothalamus (PVN) via the stria terminalis.
The paraventricular hypothalamus (PVN) releases corticotrophin-releasing hormone (CRH), which affects the anterior pituitary.
The anterior pituitary releases adreno-corticotropic hormone (ACTH).
In response to ACTH, the adrenal glands release cortisol.
Cortisol influences many neurons in the brain, increasing the release of several neurotransmitters.

Question 31

HPA Axis: Negative Feedback

Answer 31

The hippocampus contains receptors for glucocorticoids, such as cortisol.
When the hippocampus binds cortisol, it acts to inhibit CRH release by the hypothalamus
With less CRH, less ACTH and cortisol will be released

The Amygdala stimulates CRH release in the PVN.

Question 32

Stress and Health – Hippocampus

Answer 32

Cortisol increases the amount of calcium entering neurons—too much can be neurotoxic.

Neurons in the hippocampus are particularly vulnerable to stress, impacting negative feedback of stress response

Question 33

Cellular Changes in Response to Stress

Answer 33

The Hippocampus dendrites atrophy and neurogenesis is inhibited.

Thr Amygdala dendrites hypertrophy.

Question 34

Stress and Health - Immunity

Answer 34

Acute stress may be beneficial; it increases immune system activity, increasing number of immuno-responsive cells

Chronic or prolonged stress compromises the immune system.

Catecholamines and cortisol are immunosuppressive; they suppress the activity of lymphocytes (white blood cells) and affect the production of cytokines (antibody-recognizing cells).

Consequently, people experiencing chronic stress are more vulnerable to disease.

Question 35

Stress and Health - Cardiovascular

Answer 35

The cardiovascular system is particularly vulnerable to stress.
–Stress increases blood pressure, and prolonged high blood pressure can damage the heart or cause a stroke.

“During the Siege of Leningrad, BP increased dramatically. The effect of that siege combined with its starvation conditions cast a long lasting effect on cardio health. Even 50 years later, survivors of the Leningrad siege had increased BP and increased mortality from cardiovascular disease.” (Sparen P, et al., 2004)

Question 36

Stress and Health

Answer 36

Whether stress has a negative impact on health depends on a variety of factors, including social support, personality, and attitude.

Attitudes about stress and a sense of control may influence health.

Question 37

Cannon-Bard Theory

Answer 37

Autonomic arousal and identification occur simultaneously and independently.