38 RESEARCH OF RESPONSE TIME

The reaction is the response of the body to an external or internal stimulus. The reaction time is the time interval from the beginning of the action of the stimulus to the occurrence of an organism response to it.

Physiologists Z. Exner and F. Donders were the first to start measuring time using the psychic components of the reaction. Z. Exner measured elementary mental reactions in stages: first, auditory, then visual and skin.

The characteristics of the measurement of the primitive reaction were investigated by him depending on the age of the subjects, on the saturation of the stimuli, the effects of fatigue, the action of alcohol, etc. It was in the works of Z. Exner that the term “reaction time” arose.

While Z. Exner studied the definition of the time of nervous excitement in various parts of the reflex arc, another physiologist, F. Donders, proceeded to measure directly the mental link of a single reaction. He determined that the duration of the mental component of the reaction does not exceed 1/10 s; to clarify the result, F. Don-derss introduced terms such as the act of discrimination and the act of choice, which made it possible to calculate the reaction time more accurately.

There are two ways to study the reaction time.

1. Measuring the time of an elementary mental reaction.

A psychic reaction is a primitive sensory-motor reaction to a particular stimulus. The reaction time is formed from:

1) latent (hidden) period;

2) delays in the flow of mental processes, depending on the personality characteristics of the subjects. The boundaries of the delays for the light stimulus are 180–200 ms, for the sound one - 150–180 ms. Required devices: a meter of clearly following reactions, a design for the delivery of light and sound signals.

Conducting research. The subject is located directly in front of the device, holding a finger on the button. Instructions are provided: "When a sound or light signal appears, instantly press a button."

2. Stages of research:

1) situation of complete silence and psycho-physiological rest of the subject;

2) abstraction of the subject through the formation of conscious interferences when performing sensomotor reactions.

Each stage of the examination includes the performance of 10 sensorimotor reactions by the test subjects - to sound and light stimuli at intervals of 3-5 s. Preliminary the command is given: “Attention!” The time of reactions to each stimulus is recorded. After that, a second series of stimuli is provided, but already in the conditions of creating noise - noises and sounds of different nature. Also recorded the reaction time.