Galvanic Skin Response (GSR)

GSR operates by detecting variations in the skin’s electrical conductance through electrodes placed on areas like the fingers or palms. The signals it generates consist of tonic (baseline) and phasic (stimulus-related) components, which can be analyzed to understand both long-term arousal levels and immediate emotional reactions.

The primary purpose of GSR measurement is to assess autonomic nervous system activity and its connection to emotional and cognitive processes. It is widely used in biofeedback, where individuals learn to regulate stress and emotions using real-time physiological data.

Applications of GSR span psychological research, clinical therapy, lie detection, affective computing, human-computer interaction, mindfulness support, and emotional well-being tracking. In biofeedback and mental health contexts, GSR helps improve self-awareness, emotional regulation, and resilience.

This document explores GSR's physiology, measurement techniques, signal components, and its applications with a focus on its role in biofeedback and emotional well-being.

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Autonomic Nervous System (ANS), Skin & Sweat Glands

Among the two major divisions of the nervous system, the Autonomic Nervous System (ANS) plays a central role in involuntary physiological responses. Since GSR measures emotional arousal, it is closely linked to the functioning of the ANS.

The Autonomic Nervous System (ANS) is a branch of the peripheral nervous system that controls involuntary physiological functions in the body, such as heart rate, blood pressure, digestion, respiration, and sweating. It operates automatically, without conscious effort, and plays a critical role in maintaining homeostasis (the body’s internal balance).

The ANS is divided into two major subdivisions:

• Sympathetic Nervous System (SNS): Activates the body’s “fight or flight” response during stress or emotional arousal. It increases heart rate, dilates pupils, and stimulates eccrine sweat glands, which directly influences GSR.

• Parasympathetic Nervous System (PNS): Promotes the “rest and digest” state, helping the body relax and conserve energy.

The sympathetic nervous system responsible for controlling the fight and flight response of the body is involved in the sweat secretion process. Here is the step-by-step breakdown of the process involved-

Sweat Secretion Mechanism (Eccrine Glands)

Step 1: Emotional or Thermal Stimulus

• The body detects a stressful situation, emotional arousal, or increased temperature.

• This activates the hypothalamus in the brain, the control centre for homeostasis.

Step 2: Activation of the Sympathetic Nervous System (SNS)

• The hypothalamus signals the SNS to respond.

•  The SNS controls sweat secretion via cholinergic fibers — this is unique, as most SNS responses use norepinephrine.

Step 3: Cholinergic Sympathetic Fibers Transmit Signals

• SNS sends electrical signals through Cholinergic preganglionic fibers in the ANS to autonomic ganglia.

• These synapse with Cholinergic postganglionic sympathetic fibers which carry the signal to the eccrine sweat glands.

Step 4: Release of Acetylcholine (ACh)

• The postganglionic fibers release acetylcholine at the sweat gland terminals for stimulation of the eccrine glands.

Step 5: Acetylcholine Binds to Muscarinic Receptors

• Acetylcholine binds to muscarinic receptors located on the membrane of eccrine sweat gland cells.

• This triggers a signal transduction cascade inside the glandular cells.

Step 6: Sweat Production Begins

• The binding causes glandular epithelial cells to actively transport electrolytes (like Na⁺ and Cl⁻) into the sweat duct.

•   Water follows osmotically, creating sweat.

•   Sweat is secreted onto the skin surface through ducts in the epidermis.

Step 7: Increased Skin Moisture Leads to GSR

• The released sweat increases the moisture on the skin.

• This reduces skin resistance and increases electrical conductance.

• Electrodes placed on the skin can now detect this change as part of the Galvanic Skin Response (GSR).

Beginner’s Guide to Take GSR Readings

1. Prepare the Equipment

Make sure you have a GSR device with all the main hardware components: electrodes, wires, power supply, signal conditioning circuit, analog-to-digital converter (ADC), microcontroller, and a way to connect to a computer or phone (USB, Bluetooth, etc.).

2. Attach the Electrodes

Place the two electrodes (sensors) on your skin, usually on the index and ring fingers of one hand. Use Velcro straps or adhesive patches so they fit snugly but not too tight—tight straps may cause sweating just from pressure. If using adhesive patches, you might need a dab of conductive gel to improve signal quality.

3. Connect Everything

Make sure the wires from the electrodes are securely plugged into your GSR device. Check that the device is powered on and, if needed, connected to your computer or phone. 

4. Get Ready to Record

Rest your hand comfortably on a table so you don’t move during the recording—movement can cause errors in your data. Let the electrodes "settle" for a minute to get a stable reading.

5. Start the Recording

Use the software that came with your GSR device to start recording. Record a baseline: Sit quietly for 1 minute and let the device measure your normal skin conductance level (SCL). Watch the live data on your screen to make sure the signal looks stable and is not too noisy.

6. Introduce a Stimulus (Optional)

If you want to see how your skin responds to stress or emotion, you can introduce a stimulus: ask a question, show a picture, or play a sound. Mark the moment in your software when the stimulus happens, so you can see how your GSR changes in response.

7. Observe and Interpret the Data

The GSR device will show changes in skin conductance (measured in microsiemens, µS).

Understanding and interpreting GSR readings

Interpreting a GSR (Galvanic Skin Response) graph involves recognizing two main components: tonic (baseline) and phasic (response) activity. Here’s how to read and understand each part: 

1. The GSR Graph: What You See

• X-axis: Time (seconds or minutes)

• Y-axis: Skin conductance (measured in microsiemens, µS)

The graph shows how your skin’s ability to conduct electricity changes over time, reflecting your physiological arousal and emotional responses.

2. Tonic (Baseline) Readings

The tonic level is your skin’s baseline conductance when you are calm and at rest, without any immediate stimulus.

• On the graph: It appears as a relatively flat or slowly changing line, representing your steady state.

• Interpretation: A stable tonic level means you are relaxed. A higher tonic level can indicate general arousal, anxiety, or stress.

3. Phasic (Response) Readings

Phasic responses are rapid, temporary increases in skin conductance caused by specific stimuli (like a loud noise, a surprising image, or a stressful question).

• On the graph: These appear as sharp upward spikes or bumps above the tonic level.

• Interpretation: Each spike reflects an emotional or physiological reaction. The size (amplitude) and timing (latency) of these spikes can indicate how strong and how quick your response was.

How to Read and Interpret the Graph

Component What to Look For What It Means

Tonic Level Flat/steady baseline Calm, relaxed state; overall arousal level

Phasic Response Sharp upward spikes Emotional or physiological response to a stimulus

Amplitude Height of spike Strength of the reaction

Latency Time from stimulus to spike Speed of the response

Recovery Return to baseline How quickly you calm down after a response

• Before stimulus: Observe the baseline (tonic) level.

• After stimulus: Look for a spike (phasic response). The larger and quicker the spike, the stronger and faster your emotional reaction.

• After the spike: The graph should return toward the baseline as you recover.

Example

• Start recording: The graph shows a steady line (tonic level).

• Introduce a stimulus: You hear a sudden sound.

• Phasic response: The graph shows a rapid spike.

• Recovery: The line gradually returns to the baseline as you relax.

Summary

• Tonic readings = your baseline, steady state.

• Phasic readings = quick spikes due to specific events or stimuli.

GSR graphs help you visualize and measure both your general state and your immediate reactions, giving insight into your emotional and physiological arousal.

Research in Happiness Science

Applications of GSR

Psychophysiological Research

GSR is widely used in psychological studies to measure emotional arousal. It helps researchers examine the relationship between physiological states and cognitive or emotional processes.

Mental Health Monitoring

In clinical settings, GSR is used to assess stress, anxiety, and emotional regulation. It can support diagnosis and therapy by tracking changes in autonomic nervous system activity over time.

Human-Computer Interaction (HCI)

GSR data is utilized in adaptive systems that respond to a user’s emotional state. For example, interfaces may adjust their complexity or feedback style based on detected arousal levels.

Biofeedback Therapy

GSR is incorporated into biofeedback systems that teach individuals to regulate their physiological responses. It is particularly effective in managing stress, anxiety, and certain psychosomatic conditions.

Market and Consumer Research

Companies employ GSR to evaluate consumers’ unconscious emotional reactions to products, advertisements, or brand experiences. It provides insights into emotional engagement and decision-making.

Educational Technology

GSR sensors are used to measure student engagement and cognitive workload. Educators and developers use this data to design more responsive and personalized learning environments.

Lie Detection and Security

Although controversial, GSR remains a component of polygraph testing. It is used in conjunction with other physiological signals to detect deception by identifying physiological arousal.

Virtual Reality (VR) and Gaming

In immersive environments, GSR can enhance user experience by allowing dynamic content adjustment based on real-time emotional states, leading to more personalized and engaging interactions.

Sleep and Fatigue Monitoring

GSR measurements contribute to systems that detect stress-induced insomnia or fatigue by monitoring sympathetic nervous system activity during rest and sleep cycles.

Affective Computing and Wearable Technology

GSR is integrated into wearable devices that continuously monitor emotional wellbeing. These tools are increasingly applied in mental wellness tracking and emotion-aware AI systems.

Emotional Intelligence & GSR for Science of Happiness

GSR and Emotional Intelligence

Emotional Intelligence (EI) refers to a person's ability to recognize, understand, and regulate their emotions and those of others. GSR, which tracks changes in skin conductance resulting from sweat gland activity regulated by the sympathetic nervous system, is a physiological indicator of emotional arousal. The connection between GSR and emotional intelligence lies in its ability to provide real-time feedback about one's emotional reactivity.

1. Self-Awareness

GSR data offers an objective way to detect unconscious physiological responses to emotional triggers. Individuals can use this information to develop heightened self-awareness, a foundational component of EI. When someone observes an increase in skin conductance during stressful or emotionally charged situations, they gain insights into their inner emotional states that may not be easily accessible through introspection alone.

2. Self-Regulation

GSR feedback plays a valuable role in self-regulation training. Through biofeedback mechanisms, individuals can learn to modulate their physiological responses, such as reducing skin conductance during anxiety-inducing tasks. This supports the development of emotional control and resilience, particularly under high-pressure environments, which are key aspects of EI.

3. Empathy and Social Skills

Emotional responses often manifest physiologically before they are consciously acknowledged. In interpersonal contexts, GSR measurements can aid researchers and clinicians in studying empathic responses. For example, synchrony in GSR responses during social interactions is considered a potential biomarker for emotional attunement between individuals. These insights can inform training programs aimed at enhancing empathy and communication.

4. Emotional Learning and Feedback

When integrated into emotional learning systems or training programs, GSR can help users understand how specific stimuli—such as images, sounds, or social scenarios—affect them emotionally. It also serves as an evaluative tool for therapists or educators to monitor a person’s emotional development over time and adjust strategies accordingly.

GSR in the Science of Happiness

The science of happiness investigates the factors that contribute to human well-being, contentment, and emotional flourishing. Emotional arousal plays a central role in the experience of happiness, and GSR is a powerful tool for capturing this dimension objectively.

1. Measuring Positive Emotions

Studies have shown that even though GSR cannot differentiate the valence (positive or negative) of emotions, it effectively quantifies arousal. High-arousal positive emotions—such as joy, excitement, and enthusiasm—are typically accompanied by increases in skin conductance. When used alongside self-report tools or contextual data, GSR enhances the understanding of how happiness is experienced on a physiological level.

2. Evaluating Mindfulness and Meditation

Mindfulness-based practices and meditation have been consistently linked to increased happiness and psychological well-being. During mindfulness sessions, GSR tends to show a reduction in arousal, reflecting decreased stress and increased relaxation. Repeated monitoring of GSR during such interventions can validate their effectiveness in promoting calm and contentment.

3. Behavioral and Cognitive Therapies

Positive psychology interventions—such as gratitude journaling, acts of kindness, and strengths-based reflection—aim to increase long-term happiness. GSR can serve as a non-intrusive method to measure how these interventions impact the individual’s physiological state over time. Reductions in stress-related arousal in response to these activities suggest improvements in overall emotional health.

4. Quantifying Emotional Engagement

In happiness research, emotional engagement is a key outcome metric. Whether the context is a positive social interaction, exposure to nature, or participation in creative activities, GSR responses help to quantify levels of involvement and enjoyment. This makes it an important instrument in both research and applied positive psychology.

Limitations of GSR (Galvanic Skin Response)

While Galvanic Skin Response is a valuable tool for measuring emotional arousal, it has several important limitations that must be considered in both research and applied contexts:

1. Lack of Emotional Specificity

GSR measures physiological arousal, not the valence of the emotion. This means it can indicate that a person is emotionally stimulated but cannot determine whether the emotion is positive (e.g., joy, excitement) or negative (e.g., fear, anger). To identify the type of emotion, GSR data must be paired with other physiological or psychological measurements, such as facial expression analysis, heart rate variability, or self-reports.

2. Susceptibility to Environmental Factors

Skin conductance is affected by external conditions such as temperature, humidity, and skin dryness. For instance, cold environments or dry skin can reduce the accuracy of measurements. These environmental variables can introduce noise in the data, especially during long recording sessions or fieldwork.

3. Individual Differences

There is considerable inter-subject variability in GSR readings. Factors like age, gender, hydration level, skin condition, and medication can influence baseline skin conductance levels and response amplitudes. As a result, comparisons across participants require careful normalization, and GSR is best used for within-subject studies rather than between-subject comparisons.

4. Movement Artifacts

GSR sensors are highly sensitive to movement. Even slight finger or hand movements can introduce noise or false readings in the data. This makes it challenging to use GSR in dynamic or naturalistic environments without introducing signal artifacts.

5. Lag in Response Time

There is a time lag of about 1–3 seconds between the emotional stimulus and the detectable change in skin conductance. This delay makes real-time interpretation of emotional shifts more difficult, especially in fast-paced or interactive settings.

6. Limited Contextual Insight

GSR alone provides no contextual information about the stimulus causing the emotional reaction. Without pairing it with behavioral, situational, or self-reported data, it is impossible to determine what exactly triggered the physiological response.

7. Non-specific Arousal Triggers

Aside from emotions, GSR can be influenced by non-emotional factors such as physical exertion, caffeine intake, pain, or cognitive load. This non-specificity limits the use of GSR in isolating emotional reactions unless such variables are strictly controlled.

Demonstration Video

Experiments of GSR

Experiment - 1: Investigation of GSR during VR Gaming

Aim

To observe GSR changes during excitatory VR gaming using EmotiBit.

Introduction

Virtual Reality (VR) gaming offers immersive experiences that can be enhanced by understanding players’ physiological and emotional states. Galvanic Skin Response (GSR), which measures skin conductance linked to emotional arousal and stress, is a valuable indicator of user engagement during gameplay. EmotiBit, an open-source wearable sensor, enables real-time collection of GSR and other biometric data without disrupting the VR experience. This experiment uses EmotiBit to record baseline and in-game GSR data to analyze how physiological responses change during VR gaming. The findings aim to support the development of adaptive VR systems that respond dynamically to players’ emotional states, improving immersion and overall user experience.

Objective

To observe and measure changes in Galvanic Skin Response (GSR) in response to high-arousal stimuli during a VR-based shooting game using EmotiBit biosensor.

Expected outcome

Galvanic Skin Response (GSR) readings will be higher during VR gameplay compared to baseline, indicating increased physiological arousal and emotional engagement in the immersive environment.

More About Experiment More About Emotibit

Experiment - 2: GSR Response for Relaxing Sounds

Aim

To observe the GSR response to a relaxing stimulus using a Physiograph/ Polygraph.

Introduction

Have you ever felt your hands getting sweaty when you're nervous or anxious? That’s a sign of your body responding to stress. The Galvanic Skin Response (GSR) helps us measure this reaction by detecting changes in the skin’s ability to conduct electricity, which increases with sweating. Because sweating is controlled by the nervous system, GSR can tell us a lot about a person’s emotional state.

In this experiment, we wanted to see whether listening to calm and soothing sounds like gentle rain, soft music, or flowing water can help relax the body. To do this, we used a polygraph to monitor participants’ GSR while they listened to relaxing audio. Our goal was to see if the body showed signs of relaxation, such as reduced arousal or tension, when exposed to peaceful sounds.

Objective

To see if the body showed signs of relaxation, such as reduced arousal or tension, when exposed to peaceful sounds.

Expected outcome

In studies such as Frontiers in Psychology (2018) and Joshi et al. (2020), participants showed reduced skin conductance when listening to soothing music, suggesting decreased emotional arousal. Based on these findings, we expect a similar outcome in this study, where the calming sound is anticipated to produce a gradual increase in GSR resistance, reflecting increased physiological relaxation.

More About Experiment

References

• Pedersen, M., Soyyilmaz, D., Bülow, P., Justinussen, J., & Mowla, L. (2025a, January 16). Galvanic skin response (GSR): The Complete Pocket Guide. iMotions. https://imotions.com/blog/galvanic-skin-response/

• Castelleti, M., Tonon, G., Montagna, A., ErCarlo Castagnoli, E. D., & Berné, E. (n.d.). Galvanic skin response—extinction biofeedback training for psychogenic abdominal pain: A validation protocol. https://www.scirp.org/journal/paperinformation?paperid=133246 

• MR;, N. Y. L. P. (n.d.). Clinical efficacy of galvanic skin response biofeedback training in reducing seizures in adult epilepsy: A preliminary randomized controlled study. Epilepsy & behavior : E&B. https://pubmed.ncbi.nlm.nih.gov/15123023/ 

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• Critchley, H. D. (2002). Electrodermal responses: What happens in the brain. The Neuroscientist, 8(2), 132–142. https://doi.org/10.1177/107385840200800209. 

• Dawson, M. E., Schell, A. M., & Filion, D. L. (2007). The electrodermal system. In J. T. Cacioppo, L. G. Tassinary, & G. G. Berntson (Eds.), Handbook of psychophysiology (3rd ed., pp. 159–181). Cambridge University Press. https://doi.org/10.1017/CBO9780511546396.007

• Stern, R. M., Ray, W. J., & Quigley, K. S. (2001). Psychophysiological recording. Oxford University Press.

• Boucsein, W. (2012). Electrodermal activity (2nd ed.). Springer Science+Business Media. https://doi.org/10.1007/978-1-4614-1126-0

• Benedek, M., & Kaernbach, C. (2010). A continuous measure of phasic electrodermal activity. Journal of Neuroscience Methods, 190(1), 80–91. https://doi.org/10.1016/j.jneumeth.2010.04.028