Sapolsky, Chapter 13

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Sapolsky, Chapter 13

• Why is Psychological Stress Stressful?

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Bioengineering

• Input-output relationship precise, logical,
  mechanistic.
• Blood pressure, hypoglycemia feedback mechanisms
  maintain values within proper limits.
• Body is sensitive to size of stressor, rate of
  change.

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Selye crew

• Some physiological mechanisms respond similarly
  to hot and cold and injury, etc.
• But Selye was still committed to PHYSIOLOGICAL
  mechanisms of stress response.

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John Mason

• But response to pain can be altered by
  environment.
• Mason All stress responses are psychological
  responses.
• Rabble of psychologists muddying up the picture!

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Mason vs. Selye

• Mason monkey feeding experiment
• Some didnt get fed either in room with those
  that did get fed or in room by themselves.
• Only those that saw others being fed showed
  stress response.
• Psychological stress alone can ? stress response.

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• Selyes retort Not ONLY psychological stress!!
• Surgery ? stress response in anesthetized
  animals!

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Outlets for frustration

• Jay Weiss
• Rats outlet for frustration gnaw on wood
• Even imagining outlets helps. (POW)
• Displaced aggression in humans and rats
• He doesnt get ulcers, he gives them!
• Do something positive exercise
• Stress response gears body up for exercise.

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Social support networks

• Encounter stressor with other people
• Friends help strangers make things worse.
• Baboons
• Low ranking males have high GCs.
• All in unstable social groups have high GCs.
• Low ranking males less stress if they groomed
  females or played with kids.

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Baboons grooming
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Social support networks

• Humans various stressors w/ or w/o a friend
• Friend lowered cardiovascular response.
• Humans stepchildren have higher GCs than
  biological children.
• Socially isolated people overly active SNS ?
  increased blood pressure, platelet aggregation,
  heart disease ? die at earlier age.
• 2-5 X more likely to die of heart disease.
• Type A w/ TV crew

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Predictability

• Warning signal 2 pieces of info
• When stressor is about to happen
• The rest of the time its NOT about to happen.
• Familiarity with stressor reduces stress response
• Norwegian military parachute training

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Unpredictability

• Rats intermittent, changed to random food
  reinforcement
• Loss of predictability ? stress R
• Bird in Arctic (5o) vs. bird in tropics (60o)
• Stress-related disease sometimes ? HIGHER among
  people with lower rate of stressors
• Blitzkrieg more ulcers in suburbs
• Humans Information may even lower stress
  response DURING stressor.

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Control

• Rat can press lever to turn off shock ? less
  stress
• Take away the lever ? massive stress R!
• Even if lever not connected still helps if rat
  (or human turning off noise) THINKS it works.
• Exercise helps IF person or rat has control over
  it.

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Control

• Too much control can also be bad
• Air traffic controllers
• Worst problem is high demand and low control
• Planes are safer than cars, but people are more
  frightened to ride in planes.
• Controlling reward is preferred over free reward
• Rats, pigeons, and children of wealthy people

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A perception of things worsening

• Rats
• 50 or 10 shocks on day 1
• 25 shocks on day 2
• Rats with the increase on day 2 had greater
  stress R.
• Baboons
• Social rank climbing or dropping?

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Not so fast!

• Which factor is more important?
• Winning lottery (things getting better) is
  usually good (even though unpredictable).
• Some people persist in known misery rather than
  try to change for the good.
• Some lack of control/predictability can be good
• Roller coaster ride, mystery novel, random act of
  kindness.
• Boring job can be a drudge.

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Subtleties of predictability

• How predictable is the stressor in absence of
  warning?
• Warning less effective for either very rare or
  very common stressors.
• How far in advance is the warning?
• Not helpful either immediately before or too long
  before stressor.
• How specific is the warning?
• Orange alert

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Subtleties of control

• If you think you have control, but dont, you may
  feel guilt if stressor occurs.
• Blaming others for what happens to them.
• Woman wearing suggestive clothes
• Minorities not assimilating

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Subtleties of control

• Strong internal locus of control
• Greater stress response if uncontrollable bad
  event occurs.
• Joseph Bradys executive monkeys
• More ulcers, compared with yoked controls
• But monkeys not randomly assigned

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Summary

• Both physical and psychological stressors can ?
  stress response.
• Outlets for frustration reduce stress R.
• Social support networks do, too.
• Predictability may help, if not too far ahead of
  stressor or too close.
• Control helps, within limits.
• Perception of things getting better helps.