Goal: Learn about the components of the EDA signal and its key characteristics

• Chapter 7 on The Electrodermal System in: John T. Cacioppo, Louis G. Tassinary, Gary G. Berntson - Handbook of Psychophysiology (Cambridge University Press, 2007). The most important parts:
  • Physical context (pp. 160-164)
  • Inferential context (pp. 164-167)
  • Advantages and disadvantages (pp. 167-168)

1. Q&A Session:
   1. What is actually measured when electrodermal activity is measured?
   2. How is the EDA signal related to emotional changes?
   3. What two main components can we separate the EDA signal into? What are they related to?
2. Measurement time:
   1. The most common way to measure EDA is to place two electrodes on the fingers (index and middle) - as presented on page 7 in EDA User Manual – or on the wrist (location 2 and 3 in the paper)
      1. Many other locations are used in studies – if you are interested, check the paper
      2. Note: there is no need to use a reference electrode for EDA measurement
   2. Follow the Devices 101 lab to connect the biosignalsplux with the PC
   3. Use the EDA Datasheet and EDA User Manual to properly record the EDA signal
   4. Tasks:
      1. The EDA signal is very sensitive to changes in skin moisture (they change the conductivity of the skin). Check if this is really the case by comparing the baseline signal level (SCL) on dry skin and on wet skin (you can go to wet your hand in the bathroom)
      2. The EDA signal is related to emotional responses – the stronger the response, the greater the amplitude of the SCR – so after putting on the sensors, try to elicit a strong emotional response in the subject! (e.g., try to frighten or pinch the arm)
   5. At the end of class:
      1. clean the equipment with disinfectant wipes
      2. throw away the disposable electrodes (or keep them as souvenirs )
      3. pack all items in bags
      4. make sure all items are in the case:
         • biosignalsplux hub
         • bluetooth dongle
         • 4 sensors (each has a sticker with the name on it)
         • reference electrode (single, no stickers)
         • power supply
      5. give the case to the teacher
3. Practice session:
   1. Today's lab is placed in one Jupyter Notebook: Electrodermal activity (EDA/GSR)

• Chapter 7 on The Electrodermal System in: John T. Cacioppo, Louis G. Tassinary, Gary G. Berntson - Handbook of Psychophysiology (Cambridge University Press, 2016) – great handbook if you want to know more about all the physiology behind analysed signals (3rd edition available online via EBSCO)
• Boucsein et al. - Publication recommendations for electrodermal measurements (How to perform EDA measurements properly and how to describe them in the publications to facilitate studies replication)
• van Dooren et al. - Emotional sweating across the body: Comparing 16 different skin conductance measurement locations (besides classical hand locations, there are other placement for EDA electrodes; they are compared in this paper)
• Posada-Quintero and Chon - Innovations in Electrodermal Activity Data Collection and Signal Processing: A Systematic Review (Sensors, 2020)

• NeuroKit2 (toolbox for BVP, ECG, EDA, EEG, EMG, EOG, Respiration; it has a physiological signal generator)
• BioSPPy (toolbox for BVP, ECG, EDA, EEG, EMG, Respiration)