Studies in Vision: IV. The Interactions of Rods and Cones in After-Sensations

Fixed-ratio (FR) size was increased for pigeons (N = 6), while the number of eating responses at reinforcement was either held constant or increased. Also, FR size was held constant while the number of eating responses at reinforcement was increased. Major findings were as follows: (a) when eating responses were held constant, higher FR requirements led to stable key rates and postreinforcement pauses; (b) allowing more eating responses at successively higher FR requirements led to stable key rates and postreinforcement pauses; (c) at high FR requirements which produced low key rates, increasing the number of eating responses at reinforcement increased key rates; and (d) eating response rates varied systematically with key rates.