BCIA Peripheral Biofeedback Modalities (EMG, Temperature, GSR) 1 — Questions and Answers
Question 1: Which peripheral biofeedback modality measures electrical activity produced by skeletal muscle contractions?
- Galvanic skin response (GSR)
- Electromyography (EMG) (Correct answer)
- Thermal biofeedback
- Heart rate variability (HRV)
Correct answer: Electromyography (EMG)
Electromyography (EMG) detects the electrical potential generated by muscle cells during contraction, making it the primary modality for monitoring skeletal muscle tension.
Question 2: In thermal biofeedback, the sensor is most commonly placed on which anatomical site for general stress training?
- The forehead
- The forearm
- The index or middle finger (Correct answer)
- The earlobe
Correct answer: The index or middle finger
Finger temperature (typically the index or middle finger) is the standard sensor placement for thermal biofeedback because peripheral vasodilation and constriction are reliably reflected there.
Question 3: Galvanic skin response (GSR) biofeedback measures changes in which physiological parameter?
- Skin blood flow velocity
- Electrodermal activity related to sweat gland output (Correct answer)
- Subcutaneous muscle tension
- Peripheral nerve conduction velocity
Correct answer: Electrodermal activity related to sweat gland output
GSR (also called electrodermal activity or EDA) reflects eccrine sweat gland activity, which varies with sympathetic arousal and is a standard measure of autonomic nervous system activity.
Question 4: A client with tension-type headaches would most likely benefit from which peripheral biofeedback protocol?
- GSR biofeedback targeting palm electrodes
- Thermal biofeedback at the forehead
- EMG biofeedback at the frontalis or trapezius muscles (Correct answer)
- Temperature biofeedback at the fingertip
Correct answer: EMG biofeedback at the frontalis or trapezius muscles
EMG biofeedback targeting the frontalis or trapezius muscles is the evidence-based first-line peripheral biofeedback protocol for tension-type headaches.
Question 5: During sympathetic arousal, peripheral skin temperature typically:
- Increases due to vasodilation
- Decreases due to vasoconstriction (Correct answer)
- Remains unchanged
- Increases due to sweating
Correct answer: Decreases due to vasoconstriction
Sympathetic activation triggers vasoconstriction in the peripheral capillaries, reducing blood flow to the extremities and causing a measurable drop in skin temperature.
Question 6: Which EMG electrode placement configuration records the potential difference between two active sites over the same muscle?
- Monopolar recording
- Bipolar recording (Correct answer)
- Referential recording
- Common-mode recording
Correct answer: Bipolar recording
Bipolar recording places two active electrodes over the muscle belly and measures the potential difference between them, which reduces noise and is the standard EMG configuration in biofeedback.
BCIA Peripheral Biofeedback Modalities (EMG, Temperature, GSR) 1
Which peripheral biofeedback modality measures electrical activity produced by skeletal muscle contractions?