BCIA Peripheral Biofeedback Modalities (EMG, Temperature, GSR) 2 — Questions and Answers
Question 1: The unit of measurement for skin conductance in GSR biofeedback is:
- Microvolts (µV)
- Microsiemens (µS) (Correct answer)
- Degrees Celsius (°C)
- Beats per minute (bpm)
Correct answer: Microsiemens (µS)
Skin conductance is measured in microsiemens (µS), reflecting the inverse of skin resistance (measured in ohms). Higher conductance indicates greater sympathetic arousal.
Question 2: In EMG biofeedback, the amplitude of the signal is typically reported in:
- Hertz (Hz)
- Microvolts root mean square (µV RMS) (Correct answer)
- Millimeters of mercury (mmHg)
- Watts per square meter
Correct answer: Microvolts root mean square (µV RMS)
EMG amplitude is expressed as microvolts root mean square (µV RMS), which represents the average power of the electrical signal produced by muscle activity.
Question 3: Raynaud's disease is a clinical condition frequently treated with which peripheral biofeedback modality?
- EMG biofeedback
- EEG neurofeedback
- Thermal (temperature) biofeedback (Correct answer)
- Respiratory biofeedback
Correct answer: Thermal (temperature) biofeedback
Thermal biofeedback teaches clients to increase peripheral blood flow and raise finger temperature, which is directly beneficial for Raynaud's disease characterized by excessive vasoconstriction.
Question 4: Which factor most commonly introduces artifact in surface EMG recordings?
- Client breathing rate
- Electrode movement and poor skin preparation (Correct answer)
- Ambient room temperature
- Client eye blinks
Correct answer: Electrode movement and poor skin preparation
Movement artifact from electrode displacement and impedance caused by oils or dead skin cells are the most common sources of noise in surface EMG biofeedback recordings.
Question 5: A practitioner using GSR biofeedback observes a phasic increase in skin conductance. This most likely reflects:
- Onset of deep relaxation
- A transient sympathetic response to a brief stressor or orienting stimulus (Correct answer)
- Parasympathetic dominance
- Artifact from client movement only
Correct answer: A transient sympathetic response to a brief stressor or orienting stimulus
Phasic GSR responses (rapid, short-duration spikes) are associated with transient sympathetic activation triggered by orienting responses, emotional stimuli, or unexpected events.
Question 6: For biofeedback-assisted relaxation training, thermal feedback indicating success would show finger temperature:
- Dropping below 75°F
- Rising toward or above 95°F (35°C) (Correct answer)
- Remaining constant at room temperature
- Rapidly fluctuating above and below baseline
Correct answer: Rising toward or above 95°F (35°C)
Successful peripheral vasodilation during relaxation training is reflected by finger temperature rising toward 95–96°F (35°C), indicating reduced sympathetic tone and increased blood flow.
BCIA Peripheral Biofeedback Modalities (EMG, Temperature, GSR) 2
The unit of measurement for skin conductance in GSR biofeedback is: