Effect of flickering light of different intensity on critical fusion frequency

U vezi s ispitivanjima, koji je dio vidnog analizatora odgovoran za kritičnu frekvenciju fuzije (da li periferni ili centralni dio) izvršena je serija pokusa, koja pokazuje da se subjektivna i objektivna frekvencija titranja svijetla u nekim uvjetima ne podudaraju. To pokazuje, da je subjektivna frekvencija titranja pod utjecajem procesa u neuronima centara, pa da je, dakle, i kritična frekvencija fuzije rezultat procesa u centrima.The stimulation of the eye by subfusional flickering of light reduces c. f. f. Bujas has stimulated subjects for 30 seconds with different subfusional frequencies of light intensity of 50 nits, and found that the c. f. f. reducement is the greatest with the frequency of 20 per second. C. f. f. has been measured by the light intensity of 70 nits. The same experiment was repeated but with the stimulating intensity of light of 12 nits, and the greatest reduction was with the stimulating frequency of 15 per second. This leads to a hypothesis that the experience of flickering Iight with the frequency of 15 per second and intensity of 12 nits is subjectively equal to that of the frequency of 20 per second and the intensity of 50 nits. This hypothesis is supported by Bartley\u27s observations that the subjective and objective frequencies of flickering are not identical an special circumstances, that is to say the subjective flickering is slower than the objective one. In the experiment described this difference would depend on the intensity of light. Thus, different combinations of light intensity and light frequency lead to the same functional state of the centres, i. e. to the maximum inhibition resulting in the maximum decrease of c. f. f. - C. f. f. depends on the functional state of the centres disregarding various peripheral processes which cause it. The stimulation with suprafusional light frequencies of the intensity of 12 nits does not change c. f. f. attained as a result of the stimulation of the eye with a constant light of 6 nits through the same period of time. As both intensities, according to Talbot\u27s law, are equal (the relation light - dark being 1/2 : 1/2) we can conclude that the suprafusional flickering as such has no effect on c. f. f