On reaction-times and the velocity of the nervous impulse

• Published in: Psychological review 1894-03, Vol.1 (2), p.159-168
• Main Authors: Dolley, Charles S, Cattell, J. McKeen
• Format: Article
• Language: English
• Subjects: Cutaneous Sense; Human; Motor Neurons; Neural Pathways; Perceptual Motor Processes; Reaction Time; Sensory Neurons; Spinal Nerves
• ISSN: 0033-295X; 1939-1471
• DOI: 10.1037/h0064218

Our objective was to determine the conditions which affect the length of reaction-times on dermal stimuli, and to study the application of the reaction-time to the measurement of the velocity of the nervous impulse in motor and sensory nerves, and in the motor and sensory tracts of the spinal cord. Section I. Apparatus and Methods.--In order to measure a reaction-time at least three instruments are required--one to give the stimulus and record the instant at which it is given, one to record the instant at which a movement is made, and one to measure the intervening time. We used the Hipp electric chronoscope for measuring the time, having made several improvements in its construction and regulation. With our apparatus we could measure the time of a reaction with a variable error of about 1|c (i.e. one thousandth of a sec.), and a constant error of about the same size. The variable error is practically eliminated in the average of 100 measurements, and the constant error is practically eliminated when a difference is taken. We used various methods to apply an electric shock or a blow to the skin. In the case of a blow we were able to measure exactly its force. The greater part of the apparatus was secured through an appropriation from the Bache Fund, and is the property of the National Academy of Sciences.