40 MATHEMATICAL BIOPHYSICS OF THE CENTRAL NERVOUS SYSTEM 



have reached the threshold h at the end of this time. But for a given 

 S there is a minimal t = f at which time e = h . This i (S) is the 

 minimal period of stimulation with the intensity S which just suffices 

 to produce the response. We obtain for this an equation similar to 



STIMULUS INTCNSITY S - 



Figure 2. — Comparison of theory with experiment: dependence of delay of 

 reaction upon intensity of the stimulus for auditory stimuli. Curves, theoretical 

 predictions by equation (2) ; points, experimental. (Auditory data from Pieron, 

 1920). Abscissa, intensity (on logarithmic scale) of stimulus; ordinate, interval 

 between presentation of stimulus and occurrence of response. 



STIMULUS INTENSITY S - 



Figure 3. — Comparison of theory with experiment: dependence of delay of 

 reaction upon intensity of the stimulus for gustatory stimuli. Curves, theoretical 

 predictions by equation (2) ; points, experimental. Gustatory data from Pieron, 

 1920.) Abscissa, intensity of stimulus; ordinate, interval between presentation 

 of stimulus and occurrence of response. 



