Stimulus control by dot position in pigeons

Abstract

In Experiment I positive dot-position generalization gradients were obtained following training in which pecks at a white key with a black dot in a fixed position (at either the top, bottom, left, right, or center of the key) were sometimes reinforced (S+) and pecks at a blank white key were never reinforced (S−). Single-stimulus training was not sufficient to establish control by dot position. In Experiment II negative dot-position gradients were obtained following training on a discrimination between S+ blank vs. S− dot. Implications of these and other results for excitatory and inhibitory stimulus control were discussed.