What Is the Galvanic Skin Response (GSR)?
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Medically reviewed by Leah Ansell, MD
The galvanic skin response (GSR), also known as electrodermal activity (EDA) or skin conductance, measures electrical changes in the skin caused by sweat gland activity in the palms and fingers. It can provide important information about the body’s level of physiological arousal, or activation and excitement, in response to stimuli.
The galvanic skin response is typically used in medical research or in a type of treatment known as biofeedback therapy. Learn more about the galvanic skin response, including its definition, uses, and conditions treated.
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Definition
The galvanic skin response measures the skin’s electrical changes in response to sweat gland activity in the fingers and palms. The skin tends to become a “better” conductor of electricity when you experience something intense or out of the ordinary—that is, when you are physiologically aroused.
GSR is an indicator of autonomic (involuntary) bodily response. When exposed to external or internal stimuli—such as sound, light, temperature, emotions, words, and faces—your body reacts involuntarily.
As your level of physiological arousal (meaning activation) changes, so do your autonomic responses. Arousal can be positive, negative, or neutral. For example, people tend to sweat more when they are hot, excited, or emotionally stressed. Pupils dilate when someone enters a dark room or when they see someone they are attracted to.
What Is the Autonomic Nervous System?
The autonomic nervous system regulates the actions of the body’s glands and smooth muscles, such as the reproductive organs and the circulatory, respiratory, and digestive systems. It includes the parasympathetic and sympathetic nervous systems.
The parasympathetic nervous system controls functions like sleep, sex, pleasure, and eating. Meanwhile, the sympathetic nervous system—which produces the galvanic skin response—helps to control the fight-or-flight response.
Uses
Galvanic skin response is usually measured with pain-free sensors placed on the body, often on the hands, feet, and/or fingers. Certain wearable devices, such as specially designed gloves and watches, may also be used to measure changes in skin conductance. Data about the galvanic skin response is also sometimes used in virtual reality (VR)–based therapy.
GSR information is sometimes used to gather data as part of medical research. For example, a 2020 study found that people in the intensive care unit (ICU) experienced positive changes in GSR signals in response to attention from a nurse or family member, even while in a coma. This information could be used to help to improve treatment in the ICU in the future.
Researchers and healthcare providers also sometimes measure the galvanic skin response as part of biofeedback therapy. Biofeedback therapy is a process that involves measuring the body’s physiological responses, such as heart rate, breathing, temperature, and sweating.
The person being treated gets real-time audio or visual feedback about their physiological responses. Over time, biofeedback therapy aims to gain more control over involuntary bodily functions to develop better coping skills, reduce symptoms, and treat certain conditions.
Related: 10 Breathing Exercises for Anxiety Relief
Conditions Treated
Information about the galvanic skin response has been used to treat a number of conditions, often as an aspect of biofeedback therapy or to gather more information about particular symptoms. Researchers have used GSR data to treat and learn more about the following:
Epilepsy: Research indicates that GSR biofeedback therapy can be effective in reducing seizure frequency among people with epilepsy. Biofeedback training is sometimes used to treat people with drug-resistant epilepsy or as a complementary therapy alongside anti-seizure medications.
Headache: GSR biofeedback therapy may help to reduce the symptoms of chronic headache, especially for people with tension-induced headaches.
Hyperhidrosis (excessive sweating): Studies indicate that wearable biosensors that measure GSR and sweat loss may effectively reduce excessive sweating in cases of hyperhidrosis.
Hypertension (high blood pressure): In a 2020 study, people with hypertension experienced a drop in blood pressure after a nurse-led, home-based intervention that included GSR biofeedback therapy and deep breathing exercises.
Anxiety: The galvanic skin response often plays a key role in anxiety and tension. GSR biofeedback can help people with anxiety disorders, such as phobias, learn to relax their muscles and soothe themselves in moments of stress or panic.
Schizophrenia: Several studies have found that biofeedback training can help improve certain social and cognitive skills. For example, a 2020 study found that GSR biofeedback therapy improved concentration and attention among young men with schizophrenia.
Post-traumatic stress disorder (PTSD): In addition to measurements of heart rate and body temperature, data about the galvanic skin response is often helpful in the study of novel treatments for PTSD.
Dementia: A 2021 study indicated that older adults with certain types of dementia, such as Alzheimer’s disease, experienced positive changes in galvanic skin response, heart rate, breathing, and other signs of stress or arousal after receiving care from a specially designed “social robot.”
Traumatic brain injury (TBI): The preliminary results from an ongoing study suggest that wearable biofeedback devices may decrease anxiety, increase self-esteem, boost mindfulness, and improve well-being among people with traumatic brain injuries and related medical complications.
Chronic pain: A 2019 study found that people with chronic pain experienced a reduction in both pain and inflammation after wearing an electrodermal biofeedback device for three weeks.
Nausea: Relaxation exercises that involve GSR biofeedback are helpful in the treatment of various types of nausea, including motion sickness, chemotherapy-related nausea, and pregnancy-related morning sickness.
Tourette's syndrome: Some early research suggests that GSR biofeedback training may help prevent tics (involuntary movements or sounds) among people with Tourette's syndrome.
Diabetes: Studies have found that GSR biofeedback may help some people with type 2 diabetes control their glucose levels and their related stress and anxiety symptoms.
Galvanic Skin Response and Epilepsy
Biofeedback therapy using data about the galvanic skin response has been found to be particularly effective in the treatment of epilepsy. One 2019 systematic review and meta-analysis found that people who received biofeedback training using GSR measurements experienced a 64% reduction in seizure frequency on average.
Summary
The galvanic skin response (GSR), sometimes known as skin conductance or electrodermal activity (EDA), refers to changes in the skin’s electrical and sweat gland activity in response to physiological arousal (activation). It is typically measured with sensors placed on the skin, often as part of a wearable device.
In some cases, the galvanic skin response is measured in order to gather data for medical research. Galvanic skin response signals are also measured as part of biofeedback therapy. GSR biofeedback can help to treat conditions like epilepsy, schizophrenia, dementia, and anxiety, among others.
