The photographically recorded winking reflex as elicited by a loud snapping sound was studied as regards latency, amplitude, variability and integration of the response, and the effects of three "sets" on these variables were noted. The term "set" was employed in a very broad sense, referring to the general condition of the organism when a specified stimulus is presented. Specifically, the subjects were instructed (1) to relax completely; (2) to wink voluntarily on hearing the sound; (3) to press a telegraph key on hearing the sound. It was found that the variables studied were affected differently by the three sets, and the conclusion was made that even unconditioned reflexes were conditioned on the general state of the organism. In addition, the author prepared a rather exhaustive summary of experimental conditions modifying reflex responses as reported by numerous writers on the subject.