POST‐REINFORCEMENT PAUSES AND RESPONSE RATE OF MONKEYS ON A TWO‐HAND FIXED‐RATIO SCHEDULE1

Fixed‐ratio behavior of monkeys was analyzed separately for two hands. While one hand responded on the fixed‐ratio schedule the other performed a holding response and the function of the hands changed in alternate ratio runs. After performance was stable on the fixed ratio (70 responses, two monkeys; 100 responses, two monkeys, 120 responses, two monkeys) 90 sessions of further training equalized post‐reinforcement pauses and the mean interresponse time of the two hands. Hand preference in reaching for food remained unchanged. Then, the fixed‐ratio requirement was changed (a) in small sequential steps, (b) in two large steps, and, (c) within sessions alternating two runs at a high ratio with two runs at a low ratio. The mean duration of post‐reinforcement pauses was correlated with a fixed ratio maintained throughout a session but single pauses were neither controlled by the immediately preceding nor by the following ratio run when a cue to its length was available. The mean interresponse time was insensitive to changes in fixed ratio. The fixed‐ratio performance was generally similar to that of pigeons and rats.