Cannon - Significance of the Emotional Level - Highlighted

Author: Dr. Walter B. Cannon, George Higginson Professor of Physiology, Harvard Medical School.
Concept of Emotion:
- Emotions are conditions that move individuals, often described as "moving experiences".
- Powerful emotions can dominate rational thoughts, leading to impulsive actions.
- Historical context includes thoughts on emotions by philosophers and biologists like Spinoza, Descartes, and Darwin.
- Recent research enhances understanding of the physiological nature of emotional excitement.

Characteristics of Rage:
- Physiologically, rage follows a "reaction pattern":
  - Physical manifestations: crouching posture, frowning, clenched teeth, and tight fists.
  - Deeper physiological changes: elevated heart rate, increased blood pressure, higher blood sugar levels, altered blood flow, and inhibited digestion.
- Many aspects of rage response are reflexive:
  - Rage is innate and observable from infancy.
  - Similar triggers produce consistent reactions across cultures and ages.
- Reflexes serve a purpose (e.g., defensive mechanisms).

Vascular and Metabolic Responses:
- Faster heart rate and higher blood pressure expedite oxygen delivery during physical responses.
- Increased blood sugar provides energy for muscle activity, vital during aggressive situations.

Similarities with Animals:
- Emotional expressions in humans and animals (e.g., dogs) show common behavioral patterns.
- Both humans and animals demonstrate similar visceral changes during emotional responses.

Human vs. Animal Nervous System:
- Humans have significantly more developed cerebral hemispheres compared to other vertebrates.
- Functionally, the spinal cord and brain stem exhibit quicker, uniform responses to stimuli.
- Cortical (brain) responses are slower, more variable, and easily modified.

Neuronal Patterns of Emotion:
- Research shows that the mechanisms for emotional reactions (e.g., rage) are located within the thalamic region of the brain (hypothalamus).
- Sham rage in animals with disrupted cerebral cortices indicates that the emotional expression resides there.

Cortex vs. Thalamic Control:
- Emotional responses can originate from two neural levels: cortical and thalamic.
- Even when the cortex is inactive, the thalamic region can trigger emotional expressions, demonstrating dual control.

Effects of Emotional Level:
- Emotional states like rage, fear, or stress can disrupt normal bodily functions (e.g., digestion).
- Recognized cases show deterioration in health due to emotional stress (e.g., fracture healing affected by anxiety).

Sympathetic Nervous System Function:
- Components: sympathetic, parasympathetic, and both work to maintain internal constancy.
- The sympathetic division is activated during emotional excitement, causing behaviors and bodily changes necessary for responding to threats.
- The autonomic system protects against fluctuations in internal conditions (e.g., blood sugar and blood pressure).

Ill Effects of Chronic Stress:
- Continuous emotional arousal without physical response can be detrimental to health (e.g., digestive issues, weakened immune response).
- Appeals to emotion during stress can cause biochemical disruptions and exacerbate conditions like diabetes and cardiovascular issues.

Understanding Emotional Responses:
- Emotional disturbances result from ancient brain structures shared with lower animals.
- The emotional level influences critical physiological functions, underlying the significant connection between emotional experiences and overall health.