The relationship between the strength of the conditioned stimulus and the size of the resulting conditioned reflex / by P.S. Kupalov and W. Horsley Gantt.

  • Kupalov, P. S. (Petr Stepanovich), 1888-
Date:
[1926?]
Catalogue details

Licence: In copyright

Credit: The relationship between the strength of the conditioned stimulus and the size of the resulting conditioned reflex / by P.S. Kupalov and W. Horsley Gantt. Source: Wellcome Collection.

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    in some measure diminish the influence of the stronger. Observations made by Yakovleva [7] and by ourselves incline us to this view. We found that when the strength of a tone was greatly increased the response to a complex stimulus of which it is a component becomes for the next few days irregular and smaller. Evidently new relations are set up between the components, and a certain length of time is necessary to establish a new equilibrium between light and tone. These experiments do not afford a conclusive answer to the question of the specificity of function of different parts of the brain, but they suggest that all parts of the cerebral cortex function in the same way and are subject to the same factors. The possibility of differences of functional activity is not excluded, but if such differences exist they are of a quantitative order only. In reality the determining factor is the energy which acts upon the nervous elements of the cortex. Further and more exact observations are necessary for a final decision of the question. For example, we must have exact quantitative esti¬ mations of the energy which acts upon the various peripheral receptors on stimulation, the extent to which this energy is transformed into the nervous impulse, and its strength when it reaches the cerebral cortex. If it could be demonstrated that there is an exact correspondence between the size of the reaction and the intensity of the nervous impulse which reaches the cortex, we might conclude that cerebral activity is conditioned entirely by external factors. Summary. (1) Separate employment of the components of a complex condi¬ tioned stimulus is a reliable method of determining their relative strengths. (2) In a complex of two stimuli, the main effect is produced by the stronger stimulus, and this may even inhibit the weaker component. (3) A strong light (400 candle-power lamp) and cold (0° C.) are more potent stimuli than a very faint sound. (4) The size of the conditioned reflex reaction depends upon the strength of the stimulus, that is, upon the energy transmitted to the cerebral cortex. (5) The comparative effects of different stimuli depend upon the intensities of these stimuli, regardless of the analyser to which they belong. (6) Our observations incline us to the view that the various regions