Autonomic Nervous System & Biofeedback: Stress Control
Autonomic Nervous System (ANS)
The ANS controls visceral functions, maintaining homeostasis in response to internal and external stimuli. It affects all organs and systems, operating independently of conscious will. The ANS regulates blood pressure, gastrointestinal functions, sweating, body temperature, and cardiac/smooth muscle activity.
In summary, the ANS is a complex network of nerves and ganglia, operating involuntarily. Often, responses are managed by the spinal cord, not the brain.
Sympathetic and Parasympathetic Systems
The ANS is divided into the sympathetic and parasympathetic systems, differing anatomically and functionally.
Sympathetic Nervous System (SNS)
The SNS primarily affects circulation and respiration. It increases cardiac output, causes bronchodilation, inhibits gastrointestinal secretions, and boosts metabolism. The SNS provides a rapid response to external threats.
Parasympathetic Nervous System (PNS)
The PNS conserves energy. It decreases heart rate, slows atrio-ventricular conduction, constricts bronchial smooth muscle, and causes miosis. PNS activation leads to nausea, vomiting, bowel movements, enuresis, defecation, and increased secretions.
Galvanic Skin Response (GSR)
All body tissues conduct electricity, including the skin. GSR measures changes in skin’s electrical conductivity due to physical or emotional changes.
Sudden emotions like fear or physical changes like hot flashes can trigger GSR. GSR is graphically represented but doesn’t reveal the specific cause.
GSR devices can be active (using a mild current) or passive (measuring the body’s current). GSR is used in polygraph tests as lying causes stress, altering skin conductivity, respiration, heart rate, and perspiration.
GSR is also used in psychotherapy, behavior therapy, and stress/anxiety research. Touch screens detect skin conductivity, explaining why they may not work with gloves.
Experimental Objectives: Biofeedback
Biofeedback Defined
Biofeedback enables conscious control of bodily processes normally beyond voluntary command.
Biofeedback Measures
Biofeedback measures blood pressure, breathing, heart rate, muscle tension, and skin temperature. By observing these measurements, individuals learn to alter functions through relaxation or mental imagery.
A monitor displays results for both patient and practitioner. The practitioner guides the patient through stress and relaxation techniques, showing how heart rate and blood pressure respond.
Biofeedback in Physical Activity
This practice introduces biofeedback as a tool in physical activity. In sports, biofeedback helps manage stress during competition and training, promoting relaxation and control.