Electrodermal Activity (EDA)

Electrodermal Activity (EDA) refers to the changes in the electrical properties of the skin in response to various physiological and psychological stimuli. It is also commonly known as galvanic skin response (GSR) or skin conductance response (SCR). EDA is a non-invasive method used to assess the activity of the sweat glands on the skin’s surface, which is regulated by the sympathetic nervous system.

Principle of Measurement

EDA is typically measured using electrodes placed on the surface of the skin, usually on the fingers or palm. These electrodes detect the changes in the electrical conductivity of the skin, which are influenced by the sweat gland activity. Sweating is regulated by the sympathetic nervous system’s response to stimuli such as stress, emotional arousal, or physical exertion, making EDA a valuable indicator of autonomic nervous system activity.

Applications

EDA is extensively used in various fields, including psychology, neuroscience, and human-computer interaction, due to its ability to provide insights into emotional and physiological states. It has been used to assess stress levels, emotional arousal, cognitive load, attention, and other psychophysiological responses. Additionally, EDA can be employed in lie detection tests, biofeedback therapy, and the development of affective computing applications.

Limitations

While EDA is a useful measure of sympathetic nervous system activity, it is important to acknowledge its limitations. Factors such as temperature, humidity, and skin hydration can affect the measurement accuracy, potentially introducing variability in the results. Additionally, individual differences in sweat gland activity and electrode placement can influence the signal quality, requiring careful calibration and standardization for reliable measurements.