General information about skin conductance

The term “skin conductance” refers to measurable changes in bioelectrical properties of the skin. The skin conductance depends on the activity of the skin’s sweat glands and reacts to even the smallest changes, which are far from being perceived by us as wet hands. A very small, completely harmless and imperceptible electrical voltage is applied to the skin via the two electrodes of the eSense Skin Response, over which a very small current flows. The greater the activity of the sweat glands, the moister the skin and the better the current is conducted. The skin conductance increases as a result.

The eSense Skin Response measures skin conductance in micro-Siemens (µS, µ means “millionths” and “Siemens” is the unit of conductivity). The term “skin resistance” is also commonly used to describe the same phenomenon and refers to the reciprocal of the skin conductance (1S = 1/Ω).

The activity of the skin’s sweat glands is determined by the autonomic nervous system. Sympathetic and parasympathetic nervous systems are parts of the autonomic nervous system. The sweat glands of the skin are innervated exclusively sympathetically, i.e. without the influence of the parasympathetic nervous system, and are thus a good indicator of “inner tension”. When exposed to stressful stimuli, the sympathetic nervous system activates all the emergency functions of the organism and puts it in a heightened state of readiness to act: pulse and blood pressure rise, glucose levels in the blood increase to provide a readily available source of energy, and the level of attention becomes higher. Of central importance to the measurement process explained here is that the hands become moist.

We also often know these situations from our own lives. For example, think of a speech you gave in front of a group or a job interview. If you were excited in these situations, you can certainly remember the cold, proverbial sweaty hands?

One theory on the cause of this phenomenon is that our ancestors’ moist hands gave them a better grip when grasping in stressful situations, such as when fleeing through terrain. Once the threatening situation is over, the parasympathetic nervous system gains the upper hand: pulse and blood pressure slow down, and the glucose circulating in the blood decreases. The organism is switched to rest to ensure recovery. The hands become dry again.

The increasing activity of sweat glands and consequently the increase of skin conductance is clearly visible under the influence of a stress stimulus. This stimulus can be mental activity, emotional arousal, deep breathing or even a startle, for example, by unexpected clapping of hands or loud dropping of an object on the floor. Try it out for yourself with the eSense right now!

We combine the measurement and feedback of skin conductance in the eSense app with guided relaxation exercises, including guided meditations, and offer you an overall experience beyond biofeedback. In addition to extensive feedback options, you have the possibility to evaluate their measurements with many statistics, document your progress and export the records as CSV and PDF files. Your data belongs only to you! You have full access to the raw data.