(The video presents the text in German Sign Language)
The electroencephalogram (EEG) is a non-invasive survey method in which electronic activity in the brain is measured. Electrical potentials are very small (millivolts), thus imperceptible, and are recorded through the scalp. Therefore, special instruments are required for a measurement.
Typically, an EEG study begins with the subject putting on a cap to which the electrodes are attached. Fitting and attaching the electrodes takes about 1-2 hours. Then the subject goes into an isolated chamber to shield the subject from outside stimuli. It is important that no electrical stimuli or other distractions affect the subject in order to obtain a clear signal of brain activity. In this chamber, the subject is presented with visual stimuli that form the core of the experiment. For example, as part of a task, the subject must respond to sign language videos and match images. While the subject completes the task, the EEG is recorded via the electrodes. For each stimulus and response of the test person, a signal is sent from the test computer to the main computer where the data is stored. This is particularly important for the subsequent analysis of the results, where the stimuli and the data are correlated.