A stimulus reaction time test (DIN ISO 17488:2016) can be used to determine performance-based mental stress and attention measurement. Response time fluctuates with mental load and lengthens with cognitive load. The goal of the stimulus reaction time test is to measure this load.
The test participants must react to an unpredictable stimulus by pressing a button. The stimulus is emitted for one second or until the test participant returns a response. The next stimulus is played randomly every three to five seconds. A valid response to a stimulus exists if the subject presses the button within 100 – 2500 ms after the onset of the stimulus. Premature unrealistic responses below 100 ms and also responses longer than 2500 ms are not scored. If no response is made, this is coded as an error and is included in the calculation of the response rate.
The special feature of the stimulus reaction time test at IAD is the presentation of three stimulus modalities (see picture: visual, auditory and tactile).
The visual stimulus is attached via an LED to the eye movement goggles at a distance of 12 to 13 cm from the left eye. This head-mounted version offers the advantage that the stimulus is always in the same position in the field of view even during head movements (see video). For more information, see the dissertation by Müller (2020).