
  
What
is Applied Psychophysiology (Biofeedback)?
Biofeedback is the process of obtaining information about
psychophysiological or mind-body interactions and “feeding it back” for
training. These interactions are measured via heart rate, breathing,
CO2 breath measurement, skin temperature, sweat gland activity, muscles
tension and brain wave activity. Information is received by
noninvasive surface electrodes (sensors) and electronically amplified to
provide feedback, usually in the form of an audio tone and/or visual
feedback.
Biofeedback
uses the information that has been monitored from the sensors to help
train the client to learn how to make voluntary changes in those
biological functions and enhance self-regulation. This training helps to
increase the client’s awareness first of their body and second, of the
mind-body connection. For example, pain, stress and anxiety management
increases as self-regulation skills are learned and then applied to daily
life.

Description of
Biofeedback Modalities:
Psychophysiological Stress Profile:
The PPSP is an assessment of physiological response during
stress. A baseline measurement is obtained with respiration, sEMG,
GSR, skin temperature, EEG and/or heart rate. (Other modalities may
also be used) After the baseline, the client is given an appropriate
stressor, such as Serial 7s (counting backwards by 7’s from 100), invoking
an emotional event or math or reading task and recorded. The
stressor is discontinued and the client rests. Stress recovery time
and physiologic “hot spots” are isolated and targeted for future
training.
Skin/Surface EMG (sEMG): activity is a measure of the number of muscle motor units firing
under the sensor and is measured in microvolts (uV). It is reflective of
the client’s level of tension and motor control over a muscle or
region. Ideally the muscle should both relax and contract quickly
and efficiently. A baseline is established at each
session.
Basal Skin Response (GSR, Skin
conductance): is a phasic
measure of electrical resistance in the epidermis and is measured in
ohms. This resistance is created by autonomic activity in the
eccrine sweat glands, which is easily measured on the fingers. In
general, the higher the reading, the lower the sympathetic activity or
arousal taking place. “Higher is drier” with this
measure.
Heart
Rate (HR): is measured using a
photoplythsmograph (PPG) and should be variable. In general, we
should see an increase in HR as the client inhales and a decrease as the
client exhales. This is known as normal respiratory sinus arrhythmia
(RSA). It is a reflection of the sympathetic and parasympathetic
nervous systems correct signals to the sino-artrial node in the
heart. Working with the RSA pattern, we generalize the readings to
sympathetic and parasympathetic activity throughout the
body.
Heart
Rate Variability (HRV): is a measure of heart
rate using a Fourier Transform analysis to generate spectral display from
the raw PPG tracing. It reflects sympathetic and parasympathetic
influences on the heart. When the influences on the heart are
balanced, a spike appears around the .1Hz area of the
spectrum.
Blood
Volume Pulse (BVP): is extracted from the raw
data present in the PPG tracing. It is an indirect measure of blood
pressure and blood flow. As the signal increases we can extrapolate
that the blood pressure is dropping.
Skin
Temperature: is a measure of surface skin
temperature and is measured on the fingers and/or toes. Skin
temperature is related to vasodilatation and vasoconstriction. It is a
measure of sympathetic or arousal activation or
deactivation.
Respiration: is a
measure using a strain gauge positioned across the abdomen and/or
chest. Diaphragmatic breathing is encouraged, depending on the
client’s medical history and capnometry readings. Limited amount of
upper chest and trapezius movement is encouraged. However, the emphasis is
on effortless breathing. Signs of hyperventilation and
over-breathing are monitored and clients are educated regarding these
breathing problems. Diaphragmatic breathing decreases arousal and is
very helpful for any condition exacerbated by stress, anxiety and
pain.
Capnometry: training
with a simple breath analyzer called a capnometer. A capnometer
measures the amount of CO2 exhaled at the end of the breath, called end
tidal CO2. (The amount of infrared light absorbed by the CO2 in the
sample is displayed by a wave form or capnograph). If the capnometer
reading is low, it may indicate that the client is over breathing during
the session or they have been over breathing for awhile. The goal in
training is to work with the breathing to normalize O2 and CO2 levels
which in turn normalizes blood pH and other body
chemistries.
EEG: is a measure of
various brain frequencies, specifically frequencies referred to as delta,
theta, alpha and beta. EEG training is done for a variety of
conditions in which the clients can benefit from uptraining or
downtraining certain frequencies.
HEG: Hemoencephalography measures blood flow in cortical areas of the
brain. The premise is that if there is blood flow, the glucose and oxygen
metabolism occurs. This occurs when there is brain activity and is
encouraged for optimal function.
qEEG:
The quantitative electroencephalogram
measures the brain's electrical activity and is used as a diagnostic tool
for determining brain function and to aide in developing neurofeedback
(EEG) training protocols.
Electromyography
(EMG): measuring the electrical activity produced by muscle groups
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