Measurement of electrical activity

Many organs produce electrical activity that allows conclusions to be drawn about the current physical condition. These include:

• Brain: The electrical activity of the brain is measured as EEG.
• Heart: ECG measures the electrical activity of the heart; heart rate can be determined from it.
• Muscles: EMG can determine the electrical activity of muscles; facial muscles in particular play a role in determining facial expressions.

Measurement of eye movements and pupils

The measurement of eye movements is essential for many visual experiments. Eye movements are determined using eye-tracking technologies, which usually also measure pupil diameter.

Optical measurement methods

Using NIRS: infrared spectroscopy, the oxygen saturation of the blood can be determined optically. This makes it possible to draw conclusions about brain activity in particular.

Other procedures

In many experiments, it is common to track participants over time with cameras. Special procedures can be used to extract facial expressions and thus the participant’s current emotional state.