Force emission during bar pressing.

Abstract

This experiment was concerned with a detailed description of emission of forces by rats in a substantially conventional Skinner box as animals proceeded through various stages of learning process (specifically, operant level determinations, regular reinforcement, and extinction) without any experimentermanipulated exteroceptive discriminative stimuli. Rudimentary data of this type were obtained by Skinner (1938, p. 312), but they are—for present purposes—deficient in two respects: measure of force used by Skinner was not linear with actual force, and technique employed did not permit measuring force of single responses. A subsequent major contribution to systematic description of free force emission was made by Trotter (1956). Unfortunately, although he apparently had instrumentation capability, Trotter failed to keep records during acquisition phase of a knob-pressing operant, thereby precluding kind of response-by-response analysis presented here. Nonetheless, his comments concerning the physical properties of bar pressing behaviour remain clearest exposition of physics of bar pressing to date.