1. Ch 17: Emotion, Stress & Health

2. Fear
Biopsychological research on emotions has concentrated mainly on fear because it has 3 important qualities
The easiest emotion to infer from behavior in a variety of species
Plays an adaptive function in motivating the avoidance of threatening situations
Chronic fear induces stress

3. Phineas Gage
In 1848, Phineas Gage had a terrible accident when a 3-foot iron rod was blasted into his face, going through this brain and out the other side of his skull

4. Phineas Gage He survived!!!
He was as able-bodied & intellectually capable as before
But his personality & emotional life changed drastically

5. Phineas Gage
While he was originally a pious, respectful & reliable man; after his injury he was rude, impulsive, undependable, cursed a lot, lost his job
After his death, his skull was studied to determine the brain areas that were likely damaged
Both medial prefrontal lobes
Known to be involved in planning & emotion

6. Darwin’s Theory of the Evolution of Emotion
Observed that members of a species have the same behavioral responses to specific emotional states (ex: human facial expressions)
So the behavioral expressions of emotion are the product of evolution
Expressions of emotion evolve from behaviors that indicate what an animal is likely to do next
Over time the signals may lose their original meaning, remaining only communicative
Threat displays
Opposite messages are often signaled by opposite movements/postures (ex: aggression/submission)

7. James-Lange Theory
Emotion-inducing sensory stimuli are received by the cortex & trigger bodily changes via the autonomic & somatic nervous system, which trigger the experience of emotion in the brain

8. Cannon-Bard Theory
Emotional stimuli have 2 independent excitatory effects:
The feeling of emotion in the brain
The physical expression of emotion in the autonomic & somatic nervous systems
The emotional experience & physiological expression of the emotion are parallel processes (no causal relationship)

9. J-L vs C-B J-L: C-B: So which is right?
Emotional experience depends entirely on feedback from the ANS/SNS activity
C-B:
Emotional experience is independent of the ANS/SNS activity (yet simultaneous)
So which is right?
Both wrong!

10. Modern Biopsychological View of Emotion
Each of the 3 factors of an emotional response…
Perception of emotion-inducing stimuli
Autonomic & somatic nervous system responses
Experience of the emotion
…can influence the other 2.

11. Comparing the Theories of Emotion

13. Limbic System
A circuit of interconnected nuclei & tracts around the thalamus that are involved in emotional expression
Amygdala, mammilary body, hippocampus, fornix, cortex of the cingulate gyrus, septum, olfactory bulb & hypothalamus

14. Emotions & Facial Expression
The human facial expressions of the major emotions are universal
People from all different cultures can identify the emotion just from pictures of facial expressions
And they are very similar to those made by primates
And now I need a volunteer!

15. Emotions & Facial Expression
There are 6 primary emotions & corresponding facial expressions
Surprise
Anger
Sadness
Disgust
Fear
Happiness
All other facial expressions of genuine emotion are some combination of these 6

18. Facial Feedback Hypothesis
Your facial expression can influence your emotional experience
If you smile, it can actually cause you to feel happy!

19. Voluntary Control of Facial Expressions
Because we can voluntarily control our facial muscles, we can inhibit true facial expressions & create false ones
But the details show differences between real & fake expressions
Microexpressions
Millisecond long expressions of your true emotion that intermittently break through the fake face you are making
Slow-mo video review can show them

20. Voluntary Control of Facial Expressions
Real vs. fake smiles
Both involve lifting the corners of your mouth
But only real smiles (Duchenne smiles) also involve the muscles at the outside corners of your eyes

21. Skip 17.2 & 17.3

22. Stress & Health Stress is the body’s physiological response to threat
Stressors (experiences that cause stress) can be physical or psychological
Chronic psychological stress has been frequently implicated in poor health
The stress response is adaptive in the short term because it causes the animal to respond to the stressor, but in the long term it produces changes that are maladaptive

23. Stress Response
Stressors stimulate the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary, which then triggers the release of glucocorticoids from the adrenal cortex, which results in the stress response
Stressors also activate the sympathetic nervous system, which increases the amount of epinephrine and norepinephrine released from the adrenal medulla

24. Stress Response

25. Psychosomatic Disorders
Medical disorders with psychological causes
Stress can cause a number of medical disorders
Heart disease, asthma, skin disorders, gastric ulcers, etc
So many medical maladies can be caused by stress that almost any medical disorder could be classified as psychosomatic
Stress can increase one’s susceptibility to infectious diseases

26. Stress & the Immune System
Psychoneuroimmunology: the study of interactions among psychological factors, the nervous system & the immune system
The effects of stress on the immune system depend on the kind of stress
Acute (less than 100min) stressors improve immune function
Ex: public speaking
Eustress: stress that improves health
Chronic stressors negatively impact the immune system
Ex: caring for a sick loved one, a period of unemployment
Distress: stress that disrupts health

27. Stress & Health
Stress can also affect your behaviors which in turn decrease your immune system function
Ex: not sleeping, not eating healthy, not exercising, drug use
The behavior of a stressed person can produce stress & illness in others
Ex: stressed mother & the health of her child
Early exposure to stress can have many negative effects on development (especially brain & endocrine system)
Including prenatal stress

28. Stress & the Hippocampus
Exposure to stress can negatively affect the brain
The hippocampus is particularly susceptible to the negative impacts of stress
Likely because of the high concentration of glucocorticoid receptors in the hippocampus

29. Brain Mechanisms of Emotion
Scans have shown that brain activity associated with each human emotion is diffuse
i.e. no sadness center of the brain
Experiencing emotion or empathizing almost always results in activity in motor & sensory cortical areas
There is similar brain activity when someone experiences an emotion, imagines that emotion, or sees someone else experiencing that emotion
Think back to mirror neurons!

30. Brain Mechanisms of Emotion
The amygdala is involved in the perception of fear & other negative emotions, not so much its experience
The medial prefrontal lobes are active when emotional reactions are being cognitively supressed or reevaluated

31. Asymmetry of Facial Expressions
In most people, a facial expression is more pronounced on the left side of the face
So we pay more attention to that side to get emotional info
Even dogs have picked up on this!!
Monkeys also have asymmetrical left-biased facial expressions!

32. Asymmetry of Facial Expressions