Abstract
The construction and validation of a computerized device to test simple reaction time and decision-making time is dimmed. The device is required to demonstrate repeatability (consistency of response times from human subjects) across replications of the same experimental condition. A second requirement of the device is that it must separately and independently measure simple reaction time and the time it takes lo process one bit of information The concepts behind the construction of the box are discussed, as well ad the design of its internal circuits to achieve these specifications.