Emotion, Feelings and Motivation

Stress

Brain

Emotions

Periphery

Stress Emotions

Stress EmotionsBrain

Brain Emotions

Periphery EmotionsBrain

• 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

Which group will rate a higher thrill in the film?

Epinephrine Saline

Watch a thrilling 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

Schachter-Singer

Epinephrine’s effects

Informed

Epinephrine’s effects

Not Informed

How nervous are you? How nervous are you?

Epinephrine EpinephrineSaline Saline

Group 1 Group 2 Group 3 Group 4

Schachter’s Cognitive Experiment (1960s)

James-Lange Cannon-Bard Schachter

Peripheral stimuli

Peripheral stimuli

Emotional state: autonomic, endocrine,

skeletomotor responses

Peripheral stimuli

Hypothalamus Cognitivetranslation

Emotional state: 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

Peripheral stimuli

Peripheral stimuli

Emotional state: autonomic, endocrine,

skeletomotor responses

Peripheral stimuli

Hypothalamus Cognitivetranslation

amygdala

Conscious feelings &

emtional state

Neuroanatomy

Central or Peripheral sti

Emotional state: autonomic, endocrine,

skeletomotor responses

Conscious feelings &

emtional state

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)

Schachter-Singer

Propranolol Saline

Cahill & McGaugh’s Propranolol Experiments

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 & Monoamines1. Long-term use of reserpine may cause depression (1959)

2. Some people got euphoric when treated with iproniazid (1952)

3. 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

B. Iproniazid inhibits synaptic monoamine oxidase

C. Imipramine inhibit reuptake of norepinephrine and serotonin

Motivation

Pleasure

Love

Hierachical Drive States of Motivations

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 leptin0.01-0.04 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 ofleptin treatment, before weight loss occurred.

PNAS 2004

Experimental Self-Stimulation of the Brain Reward Pathway

The Mesolimbic Dopaminergic Pathways Important for Reinforcement

Motivational States Can Be Regulated by Factors Other Than Tissue Needs

In the presence of the drugs animals self-stimulate with a lower-frequency current that was previously ineffective.