| Abstract: | Two experiments examined between-chains and within-chain speed gradients as functions of length. The first, involving straight runways, revealed hyperbolic gradients within chains for each of three lengths, .61, 1.22, and 2.44 m. Between-chains comparisons showed a goal gradient effect confined to the start box segment and a long-chain depression effect in the last two segments. The second experiment, involving discrete-trial fixed-ratio bar-pressing schedules of FR(1 + 4), FR(1 + 8), and FR(1 + 16), showed goal gradient effects for starting speeds and for speeds across the first segment beyond start. Also, confounding effects apparent in the runway, of acceleration, deceleration, and long-chain depression, were diminished or absent in the bar-pressing situation. |
