Electrodermal activity provides an excellent insight into the activity of a person’s autonomic nervous system.
When used correctly, EDA measurements accurately detect emotional arousal and can illustrate the relationship between stimulus and physiological response.
movisens possesses many years of experience in recording electrodermal activity in an ambulatory setting. We would gladly support your project and create a concept together which tailored to your research goals.
Recommendations for EDA Monitoring
EDA measurement in everyday life
A prerequisite for recording electrodermal activity in everyday life is the correct application and placement of the electrodes, as well as a complete cleaning of the skin areas to which the electrodes are attached. In order to keep the sensor as a disturbing factor as low as possible in everyday life, movisens recommends to place the EdaMove 4 on the non-dominant hand. If you want to examine test persons who work a lot with their hands, it is recommended to place the EDA sensor on the ankle to minimize movement artifacts.
Long term measurements (≥24 h)
The EdaMove 4 records raw data of the skin resistance and skin conductance over a period of up to 4 weeks and is therefore ideally suited for the permanent examination of the emotional state of a person in everyday life.
For measurements which last more than 24 hours movisens recommends to change the adhesive electrodes 1-2 times per day.
Short term measurements ( ̴ 5 min)
The EdaMove 4 offers the possibility to check individual situations in everyday life or to record specifically selected actions. If, for example, the emotional excitement during a meeting at work or a digital experience of different target persons is to be observed, this can be realized by short-term measurements of the EDA. In order to achieve a high signal quality for measurements over a few minutes or several hours, movisens recommends the use of adhesive fleece to optimally fix the electrodes.
EDA- and Activity Measurements
In addition to electrodermal activity, the EdaMove 4 records acceleration, barometric pressure, rotation rate and temperature in a synchronized manner. This allows artifacts that typically complicate, identify and isolate the evaluation of EDA data in the ambulatory setting.
EDA- and Heart Rate Variability Measurements
If you want to investigate exactly defined effects of physical stress, you can record different sensor data synchronously. For example, to investigate the effects of fear on climbing performance, the EdaMove 4 und dem EcgMove 4 recorded data simultaneously.
EDA and Interactive Ambulatory Assessment (IAA)
The joint acquisition of physiological and subjective data in everyday life can be realized with movisensXS thanks to the integrable sensor trigger. Via a Bluetooth interface, all mobile sensors from movisens are able to transfer the results of the data measured and analyzed in real time to a Smartphone (mobile device). From this, questionnaires can be triggered in movisensXS to start a query.
This triggering enables the acquisition of subjective data exactly at the times when something physiologically interesting (increase in HR and/or acceleration) is measured. The combined use of EDA measurement and IAA allows quick and easy direct small interventions in everyday life.
Pilot study in a climatic chamber: daylight effects on aspects of health and wellbeing not related to vision
Estudo piloto em câmara climática: efeito da luz natural em aspectos de saúde e bem-estar não relacionados à visão; This pilot study was carried out in a climate chamber and analysed the influence of natural light (or its effects) on variables related to the health and well-being of individuals.
Assessment of Physiological Outcomes of Gamification in a Cultural Tourism Guide on smartphones
For more than 10 years, the Institute of Geography and Sustainability of the University of Lausanne has been working on the evaluation, protection and promotion of the geocultural heritage. It has developed an evaluation method for geotopes which is used by several other universities worldwide (Reynard, Coratza and Regolini-Bissig 2009). For this purpose, movisens has developed a smartphone-based interactive guide for didactic routes, which covers several environmental topics. Click here to discover more about "Assessment of Physiological Outcomes of Gamification in a Cultural Tourism Guide on smartphones"
The electrodermal activity is a short-term decrease of the electrical resistance of the skin, caused by the typical increase of the sympathetic tone in emotional-affective reactions. This leads to an increased sweat secretion, corresponding to an increase in skin conductivity. The unit of measurement for skin conductivity in the International System of Units is Siemens.
The EDA Sensor from movisens (EdaMove 4) uses the method of exsomatic measurement. Here a weak current is applied to the skin and either the current or the voltage is kept constant. The measurement of the conductivity, where the voltage is kept constant, is the most frequently used method, because it is the best way to compare between 2 test persons. The conductivity is measured in Siemens (1 S = 1/Ω). Since the conductivity of the skin is very low, μS is mostly used (typical: 2 - 20μS, phasic change only 0.02-1μS). Usually about 0.5 V is applied to the skin.
Short-term increases in the electrical conductivity of the skin caused by an irritation are measured. The increased conductivity of the skin occurs 0.5 to 4 seconds after an irritation and quickly flattens out again.
Here the electrical conductivity of the skin is measured over a longer period of time. This "level" of skin conductivity changes with emotional states over a longer period of time. For example, anxiety causes an increased tonic EDA. The more intense the stimulus, the shorter the reaction time.
What changes in the skin?
The sweat glands are more active, which means that more sweat is secreted and the electrical resistance of the skin decreases. When the sweat evaporates, the resistance increases. However, since an increase in conductivity can be measured just before the moisture level of the skin rises, the activity of the sweat glands themselves can also be responsible for short-term fluctuations.
What triggers the change?
The sweat glands and thus the EDA are controlled by the autonomic nervous system, which cannot be influenced deliberately. Therefore, the EDA value gives unadulterated answers which cannot be influenced directly and deliberately. However, there are many factors that influence the EDA; such as breathing, temperature, humidity, muscle activity, or reactions and emotional states that one usually really wants to measure.
When working with EDA measurements, it should be noted that the electrodermal reactions, increase in skin conductivity, occur with a certain latency to external stimuli.
Boucsein, W. (2012). Electrodermal Activity. Second Edition. Springer.