Transcript 2012-Emotion Feelings and Motivation

Emotion, Feelings and
Motivation
Emotions
Stress
Stress
Stress
Emotions
Brain
Periphery
Brain
Emotions
Brain
Periphery
Emotions
Brain
Emotions
• Whether conscious feeling follows bodily
changes (James-Lange) or bodily changes
follow feeling ?
Emotion & Feeling
• “Emotion” sometimes is used to refer only to the
bodily state (ie, the emotional state) and
“feeling” is used to refer to conscious sensation
• When frightened we not only feel afraid but also
experience increased heart rate and respiration,
dryness of the mouth, tense muscles, and
sweaty palms
James-Lange Theory (1880s)
• James wrote: “We feel sorry because
we cry, angry because we strike,
afraid because we tremble.”
A double-blind test
Epinephrine
Saline
Watch a thrilling film
Which group will rate a higher thrill in the film?
Patients in whom
the spinal cord
has been
accidentally
severed appear to
experience a
reduction in the
intensity of their
emotions.
Cannon's study of peripheral responses
to intense emotion
• fight-or-flight response (1920)
• the physiological responses to emotionally
significant stimuli are too undifferentiated
to convey to the cortex specific, detailed
information about the nature of an
emotional event.
Bard’s Experiments (1920s)
Sham rage: animals with the whole cerebral cortex removed
retain fully integrated emotional responses
By progressive
transections the
coordinated response
disappeared when the
hypothalamus was
included in the ablation
Cnnon-Bard Theory
• The Hypothalamus mediating both the
cognitive and peripheral aspects of
emotion
SchachterSinger
Schachter’s Cognitive Experiment (1960s)
Epinephrine
Saline
Group 1
Group 2
Epinephrine
Group 3
Saline
Group 4
Epinephrine’s effects
Epinephrine’s effects
Informed
Not Informed
How nervous are you?
How nervous are you?
James-Lange
Cannon-Bard
Schachter
Peripheral
stimuli
Peripheral
stimuli
Peripheral
stimuli
Hypothalamus
Cognitive
translation
Emotional state:
Emotional state:
autonomic, endocrine,
skeletomotor responses
autonomic, endocrine,
skeletomotor responses
Conscious
feelings &
emtional state
When the sound alone is given, it evokes physiological changes in blood pressure and
freezing similar to those evoked by the sound and shock together (right)
Fear and Amygdala
• Electrical stimulation of the amygdala in humans
produces feelings of fear and apprehension.
• Bilateral lesions of the basolateral complex of
the amygdala in experimental animals abolish
this learned response to fear.
• Patients with damage to the amygdala do not
learn to fear the neutral sound even though most
were consciously aware that the neutral sound
and the offensive noise were paired together.
James-Lange
Cannon-Bard
Schachter
Neuroanatomy
Peripheral
stimuli
Peripheral
stimuli
Peripheral
stimuli
Central or
Peripheral sti
Hypothalamus
Cognitive
translation
amygdala
Conscious
feelings &
emtional state
Conscious
feelings &
emtional state
Emotional state:
Emotional state:
autonomic, endocrine,
skeletomotor responses
autonomic, endocrine,
skeletomotor responses
The Hypothalamus Coordinates the Peripheral
Expression of Emotional States
• In anesthetized animals, Ranson (1932)
evoked individual conceivable autonomic
reaction by stimulating different regions of
the hypothalamus
• In 1940s, Walter Hess extended Ranson's
approach to awake, unanesthetized cats and
found that different parts of the
hypothalamus produce characteristic
constellations of reactions
Stimuli from the cortex
• In 1935 John Fulton and Carlyle Jacobsen
first reported that removing the frontal
cortex (lobotomy) had a calming effect in
chimpanzees. Within a few months of
Fulton and Jacobsen's report, Egas Moniz,
a Portuguese neuropsychiatrist, performed
the first prefrontal lobotomy in humans,
isolating the orbital frontal cortex. The
patients became tamed.
Egas Moniz performed the first prefrontal
lobotomy in humans in 1935.(1949 Nobel Prize)
SchachterSinger
Cahill & McGaugh’s Propranolol Experiments
Saline
Propranolol
Watch an emotionally arousing short story
No difference in the initial
emotional reaction to the story
A week or a month later
Reduced emotional reaction to the
story in the propranolol group
Mood & Monoamines
1.
2.
3.
Long-term use of reserpine may cause depression (1959)
Some people got euphoric when treated with iproniazid (1952)
Imipramine is an effective antidepressant (1958)
A.
Reserpine almost irreversibly blocks the uptake (and storage)
of norepinephrine and dopamine into synaptic vesicles by
inhibiting the Vesicular Monoamine Transporters
Iproniazid inhibits synaptic monoamine oxidase
Imipramine inhibit reuptake of norepinephrine and serotonin
B.
C.
Motivation
Hierachical Drive States of Motivations
Love
Pleasure
Drive states are characterized by tension and discomfort due to a
physiological need followed by relief when the need is satisfied.
Physiological Needs
• Temperature regulation involves integration
of autonomic, endocrine, and skeletomotor
responses
• Feeding behavior Is regulated by a variety of
mechanisms
• Drinking is regulated by tissue osmolality and
vascular volume
Recombinant human leptin
0.01-0.04 mg/kg/day, 18 months
Noningestive behavior of all three patients
was consistently observed to change from
very docile and infantile to assertive and
adult-like, within 2 weeks of the onset of
leptin treatment, before weight loss occurred.
PNAS 2004
Motivational States Can Be Regulated by Factors Other Than Tissue Needs
Experimental Self-Stimulation of the
Brain Reward Pathway
The Mesolimbic Dopaminergic Pathways
Important for Reinforcement
In the presence of the drugs animals self-stimulate with a lower-frequency
current that was previously ineffective.