Measurement of electrical activity
Many organs produce electrical activities which allow conclusions about the current physical condition. These include
- Brain: the electrical activity of the brain is the measured as EEG.
- Heart: ECG measures the electrical activity of the heart, from this can be determined the Heartrate.
- Muscles: by EMG the electrical activity of muscles may be determined, especially the facial muscles play a role for determine facial expressions.
Measurement of eye movements and pupils
The measurement of eye movements is essential for many visual experiments. Eye movements are determined using Eyetracking technologies, which usually also measure the Pupil diameter in combination.
Optical measurement methods
Using NIRS: Infrared spectroscopy the oxygen saturation of the blood can be determined optically. From this, in particular, conclusions about brain activities are possible.
Other procedures
In many experiments, it is usual to trace test persons with the help of cameras over time. Special procedures can be used to extract facial expressions and thus the current emotional state of the subject.