Sequential summation of excitation refers to the process in which several stimuli following one another at a short interval cause a total response that exceeds the response to each individual stimulus. This effect is due to the fact that with sequential stimulation, the previous excitation does not have time to completely fade away by the time the subsequent stimulus acts.
Thus, responses to individual stimuli are summed up, enhancing the overall response. This phenomenon plays an important role in the integration of sensory stimuli and the formation of an adequate response of the nervous system. Sequential summation underlies processes such as the processing of auditory and visual signals, as well as the generation of muscle contractions.