Foster, W. S. (1923). Reflex organic responses. In W. S. Foster, Experiments in psychology (pp. 122-131). NY, US: Henry Holt and Company.
http://dx.doi.org/10.1037/10966-009
Modern psychology holds. that actions and mental processes are not a "law unto themselves," simply following an arbitrary "fiat" of the will, but are connected with definite physical and organic conditions. This dependence is often stated more specifically as the "law" of stimulus-response (S→R) or the "law" of dynamogenesis. "No response, bodily or mental, occurs without an antecedent physical stimulus." "Every sensory stimulus, if of sufficient intensity, arouses a widespread bodily response." "Mental processes tend to 'express' themselves in organic changes." "Every change in experience, whether it is initiated by a change in the sensory stimulus or by some internal cause, is accompanied by changes in muscular tension." The law implies that the nerve impulses, which pass over the nerve tracts to higher centers of the brain, do not there "cause" consciousness and then "die out," but pass on by motor tracts and bring about changes in effectors. It implies, in other words, that the whole reflex arc is always completed. (PsycINFO Database Record (c) 2016 APA, all rights reserved)