Basic Galvanic Skin Response (GSR) Application User Guide

Contents

1. Introduction & launching the application
2. Parameters
3. Working with the Basic GSR Application (User Interface)
   1. Main Window
   2. Thresholds
   3. Audio Feedback
4. Report Functionality

Introduction

This guide introduces the GSR biofeedback application, part of the Mind-Body Training Tools suite. MBTT applications are designed to train self-regulation skills, which I sometimes call mind-body skills.

The guide has two purposes: firstly to give an overview of GSR biofeedback, and secondly to teach you how to use the software – though it is more of a reference than a tutorial.

Galvanic Skin Response (GSR) is a biological phenomenon in which the electrical properties of the skin change in response to physiological and psychological stimuli. It's a useful biofeedback parameter because it can teach us about the stress response and how to manage it. GSR is driven at the physiological level by the Sympathetic Nervous System.

Synonyms for GSR include Electrodermal Response (EDR) and Electrodermal Activity (EDA).

The specific electrical parameter that we measure is Skin Conductance (SC). You can read more about GSR and its associated parameters, and how they are used in biofeedback, in this user guide.

The guide assumes that you already have a basic knowledge of how to work with Mind-Body Training Tools software. If not, I suggest you read this Introductory Guide to Working with MBTT.

Launching The Application

To launch the application (after starting the platform program) first click on the "EMG & Peripheral" tab, then select the "Galvanic Skin Response (GSR) Basic" application from the drop-down list, then click the button to launch the app.

Parameters

The app works with a single parameter - the electrical property we measure is Skin Conductance (SC). SC is not precisely synonymous with GSR - it is a measure of GSR in the same way as RMSSD is a measure of HRV - GSR refers to the more general phenomenon.

The application calculates the rate of change of SC - since for biofeedback training we're more interested in relative changes in SC rather than actual values, the SC rate of change is a useful way to present GSR feedback.

Working With The Basic GSR Application (User Interface)

The MBTT apps have a common design scheme. The intent is that learning to use one app, can be generalised so that other apps in the suite are easy to learn.

The apps generally have three windows:

1. Main window, or trainer's window, containing parameter charts
2. Threshold window - each app has at least one threshold, but there are usually more.
3. Feedback window - in a sense, all charts and thresholds are giving feedback, but the feedback window contains controls for audio feedback plus more specialised feedback forms.

Main Window

The main window, shown here, follows the normal MBTT pattern of short term displays in the upper half, and a longer term trend chart in the lower.

TO_DO This video gives a tour of the Basic GSR app.

Thresholds

The threshold window for the Basic GSR app is shown here - there is only a single threshold.

Notice that the threshold is based on SC rate of change rather than simply SC. (Again, this is because we're more interested in relative change.)

You can update the threshold levels by dragging them with your mouse.

You can learn more about how thresholds operate in Mind-Body Training Tools in this guide.

Audio Feedback

The application offers midi feedback, tone feedback, and threshold-based contingent audio feedback. Additionally, you can transmit feedback parameters out of BioEra, for use with external feedback applications, such as the “Shadow” Feedback Utility (which is part of the Platform program).

Threshold-Based Audio Feedback

To recap, the basic concept is that the software plays a sound (actually a midi note) whenever a threshold limit (level) is crossed.

The controls for threshold based feedback are found at the bottom of the threshold controls. There is a button to activate it / turn it off. A drop-down control sets the condition or contingency: for example if set to “above”, the feedback will sound whenever the parameter exceeds the upper level. “Below” means it sounds below the lower level, and “outside” means it sounds for either of these two.

You can change the midi “instrument”, and you can have the sound repeat for each breath that meets the threshold condition, or only the first time the level is crossed.

Audio Feedback Window

The controls for audio feedback, aside from the threshold-based audio feedback discussed above, are found in a separate window shown below:

In midi feedback, a musical note is played whose pitch varies with the selected feedback parameter. Again you can opt to invert the pitch mapping.

You can select which parameter to use as the basis of feedback using a drop-down list control, and you can invert the pitch mapping if you wish, so that a higher score produces a lower tone.

Tone feedback works in the same way as midi feedback, except that a simple, constant tone is played in place of midi notes. Tone feedback could be said to have greater sensitivity, since the pitch varies continuously rather than being restricted to musical pitches (A, B, C# etc.) as midi feedback does.

Auto-Range Feature

Both midi and tone feedback have an auto-range feature, meaning they work in a similar way to trend charts. When the signal moves above or below the chart range, the chart resets so that the signal is in the middle again. The scale is maintained but the range shifts up or down.

In a similar way, if audio feedback pitch moves to the limit of the pitch range, the sound resets so that the pitch is in the middle of the range again (and the same scale is maintained).

Audio feedback is demonstrated in the following video TO_DO.

Report Functionality

Mind-Body Training Tools allows you to generate session reports and application reports.

The controls for report generation are found in the platform window, in the EMG & Peripheral tab shown towards the beginning of this document. You need to have selected the right application from the drop-down list - in this case GSR Basic.

A session report shows charts and tables for the feedback parameters summarising the whole session. You'll be asked to select one particular session, and given report options. This figure shows the report options for EMG but it's almost the same for GSR:

The application report shows the variation of the feedback parameters across multiple sessions. Typically for each feedback parameter, the software generates line charts for session means, session maxima and session minima.

Report functionality is described in greater depth here.

You can see sample reports here:

Sample Session Report from the EMG, GSR and Skin Temperature application

Sample Application Report (not from the GSR application).