There is provided herein a motion-based evaluation of reaction time that utilizes motion detection hardware of a mobile device to determine auditory and visual stimulated reaction time. In an embodiment, the subject holds a mobile computing device equipped with built-in triaxis accelerometer and gyroscope with both hands at arms length away from the face. A visual or auditory stimulus is then presented on screen via a software application that also records the response time for the individual to initiate a movement of the device. A simple reaction time test could include the movement of the device in any direction that exceeded a threshold of movement beyond what would be expected from static holding. An embodiment of a choice reaction time test would provide for specific directional movements as it related to an instructed stimulus.