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BIOPAC Skin Conductance Training

Last modified by Iris Spruit on 2026/03/23 14:18
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Contents

Introduction

This training is intended for researchers and students who want to learn how to measure skin conductance/EDA with the BIOPAC system.  

This page can be used in three ways: 

  • As a guide for trainers delivering skin conductance training 
  • As a digital handout for trainees 
  • As reference material when running a skin conductance study with BIOPAC 

This training assumes all equipment is already correctly set up and connected. If you need assistance with hardware setup, please contact labsupport@fsw.leidenuniv.nl.  

Estimated duration: ~ 30 minutes 

Learning Goals

By the end of this training, you will be able to: 

  • Have basic knowledge about BIOPAC 
  • Know what skin conductance is 
  • Understand how the BIOPAC skin conductance equipment is set up and how to use it safely 
  • Prepare a participant and apply 2 EDA electrodes correctly 
  • Use AcqKnowledge to record skin conductance data 
  • Obtain good data 

Not included in this training: 

  • Experimental design 
  • Physiological data analysis 

Materials

The following materials are required for this training: 

  • BIOPAC equipment including a skin conductance module (EDA/GSR100C, PPGED-R or EDA100D). The BIOPAC should be connected to a PC on which AcqKnowledge is installed. 
  • 2 dry disposable EDA electrodes 
  • Isotonic gel GEL101
  • Gloves 
  • Incidin OxyWipe 
  • Tissues 
electrodes_eda_edited2.png

Dry EDA electrodes

Isotonic_gel_edited2.png

Isotonic gel GEL101

Step-by-Step Training Plan

Introduction to Skin Conductance, BIOPAC and AcqKnowledge

  1. Read the Introduction section of the skin conductance page to obtain a basic understanding of it. 
  2. On the BIOPAC page read the following sections: 
  3. Open AcqKnowledge and follow the Creating an AcqKnowledge template instructions to create a template for your skin conductance module.  
    • Make sure to check the calibrate checkbox to calibrate the skin conductance module at the start of each recording:
      Acq-calibrateEDA.png
    • On SSH/FSW Lab PCs, create your own folder in C:\ExperimentData (e.g. “Training”).  
    • Save your template as Graph Template (.gtl) in your folder. 

Participant setup

Follow the Electrode preparation, Skin preparation and Electrode placement parts of the Protocol on the Skin conductance page. Make sure to involve the participant in the process: 

  • Explain what skin conductance is
  • Describe the electrode placement process 
  • Ask for consent before touching the participant and placing the electrodes. When the participant feels uncomfortable, you may ask the participant to place the electrodes with your instructions.  
  • Remind the participant they can stop at any time 

Recording the skin conductance signal

  1. Open the AcqKnowledge template you created earlier. 
  2. Start the recording. 
  3. Follow the instructions for calibrating the skin conductance module. Make sure the leads are NOT connected to the electrodes and subject when you hit calibrate (the leads are just loose). After having calibrated, you can connect the leads to the electrodes. 
  4. Explore AcqKnowledge features: 
    • Use the magnifying glass to zoom into the skin conductance waveform. 
    • Right-click the graph > Autoscale Single Waveform or Autoscale Waveforms. 
    • See additional helpful options in the Preferences and View section on the AcqKnowledge page. 
  5. Read the Tips and Tricks on the skin conductance page. See what happens when:  
    • The participant moves their fingers. 
    • The participant holds their breath.  
    • One of the electrodes comes loose. 
    • For the wireless module (PPGED-R), see what happens when the receiver and transmitter lose connection, i.e. move the participant with the transmitter away from the receiver. When the connection starts to deteriorate, the signal will show short flat lines. 

Clean-up

  1. Stop the recording and save the recording in the folder you created in C:\ExperimentData. Make sure to save the file as Graph (.acq) file. Close AcqKnowledge. 
  2. Follow the Cleaning up section on the skin conductance page. 
  3. Turn off the BIOPAC. 

Further Considerations

Safety

Review general safety information for participant-based research here: Safety - SOLO Research Wiki. 

Markers

Event markers are crucial when measuring physiological data.  

See: 

Equipment choice

BIOPAC has wired (EDA100C/GSR100C), wireless (RSPEC-R), or wired smart amplifier (EDA100D) skin conductance options. In most studies, any of these modules can be used. Wireless equipment may be preferred when participants need to move around (but beware of movement artifacts in the skin conductance signal). Note that wireless connections may drop if the participant moves too far from the receiver. In most cases, it does not matter which equipment is used. 

Compatibility with other signals and equipment

Skin conductance measurements can often be combined with many other signals and equipment such as EEG, ICG, ECG, respiration, blood pressure, fEMG, virtual reality, etc. When measuring other signals on the hand/fingers (such as blood pressure), the other hand can be used for skin conductance. Note however that the participant will not be able to use both hands in this case. Other locations for measuring skin conductance could be considered, see van Dooren, de Vries, and Janssen (2012) (Further Reading). When you want to measure multiple signals with BIOPAC, consult the Grounding section on the BIOPAC page. 

Analysis options

Several software options exist for preprocessing and analyzing skin conductance data collected with BIOPAC.  

Experimental design

Make sure to consider your preferred measurement outcome when designing your experiment: 

  • Tonic EDA: relates to the slower components and the general level of the signal over time. 
  • Phasic SCRs: the skin conductance responses reflect the faster changing elements of the signal 

Please check the literature for current recommendations.

Further Reading