General information about skin conductance

What is skin conductance?

Skin conductance describes how well skin conducts electrical current; its unit is microsiemens (µS). The eSense Skin Response applies a small electrical voltage to the skin through two electrodes and measures its conductance. Increasing sweat gland activity can raise skin conductance before your hands feel moist. Attach the electrodes as described in the preparation instructions and rest your recording hand. If readings are very low or fluctuate strongly, check contact and the troubleshooting links below before interpreting the signal for training.

For your recording: Preparing a recording and starting the app · Help with very low readings · Help with strongly fluctuating, implausible readings.

The eSense Skin Response measures skin conductance in micro-Siemens (µS, µ means “millionths” and “Siemens” is the unit of electrical conductance). 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!

The eSense app combines skin conductance measurement and feedback with extensive feedback options and guided relaxation exercises, including meditations. Compare your recordings in the archive, use the statistics and document your progress. Export recordings as CSV and PDF: use the PDF report for documentation and the CSV readings for your own charts and further analysis, for example in a spreadsheet. Your data belongs only to you. Since app versions 8.1.x, signal smoothing also applies to recorded and exported readings: the CSV contains the same smoothed readings you see in the app, not unfiltered sensor signals.