Interreinforcement Time, Work Time, and the Postreinforcement Pause

Abstract

Six rats were trained with food deliveries contingent upon their pressing a lever and holding it down for fixed, cumulative durations. Hold requirements were varied from 7.5 seconds to 120 seconds. Lever holding was maintained reliably at hold requirements as long as 30 seconds to 105 seconds for different rats. At longer hold requirements, lever holding was erratic and tended to occur only early in sessions. At shorter and intermediate requirements, the patterns of lever holding resembled those of responding under fixedratio schedules for discrete responses, with breaks in responding immediately after reinforcement alternating with relatively continuous lever holding until the next reinforcement. At longer hold requirements, postpause lever holding frequently was interrupted with additional pauses. The duration of postreinforcement pauses increased linearly with the scheduled hold requirement. However, for five of six rats, the hold requirement, which represents the actual time spent lever holding per reinforcer, accounted for somewhat less variance in pause duration than did interreinforcement time.Key words: postreinforcement pause, interreinforcement time, work time, continuous response, lever holding, rats Performance under schedules that provide reinforcement periodically, such as fixedinterval (FI) and fixed-ratio (FR) schedules, is characterized by a period of time immediately following reinforcement during which no responding occurs. The duration of this postreinforcement pause increases monotonically as the fixed interval (e.g., Harzem, 1969;Innis & Staddon, 1971;Lowe & Harzem, 1977;Schneider, 1969;Shull, 1970Shull, , 1971Skinner, 1938;Wilson, 1954) pause durations were approximately the same under FR schedules and yoked-interval schedules in which interreinforcement times matched those obtained from the FR schedules. Nevin (1973) analyzed data obtained by Berryman and Nevin (1962) and found that pause duration was a linear function of the average interreinforcement times obtained under FI, FR, and interlocking FI FR schedules. Rider (1980) found that pause duration was linearly related to average interreinforcement times obtained under alternative FI FR schedules over a broad range of schedule parameters.The good linear fit between pause duration and interreinforcement time across simple Fl and FR schedules and complex interlocking and alternative schedules raises the possibility that interreinforcement time controls pausing independently of the particular schedule of reinforcement. However, in a direct comparison of FI and FR schedules with comparable interreinforcement times, Capehart, Eckerman, Guilkey, and Shull (1980)

Extended Pausing by Humans on Multiple Fixed-Ratio Schedules With Varied Reinforcer Magnitude and Response Requirements

“…This account predicts that increasing the frequency or magnitude of reinforcement should reduce pausing. Supporting data have come from research with fixed‐ratio (FR), fixed‐interval (FI), and variable‐ratio (VR) schedules (e.g., Blakely & Schlinger, 1988; Crossman, 1971; Felton & Lyon, 1966; Griffiths & Thompson, 1973; Inman & Cheney, 1974; Killeen, 1969; Lowe & Harzem, 1977; Powell, 1968, 1969; Rider & Kametani, 1984; Schlinger et al, 1990).…”

Fixed‐ratio Pausing: Joint Effects of Past Reinforcer Magnitude and Stimuli Correlated With Upcoming Magnitude

“…Moreover, this account predicts that manipulations to enhance response strength, such as increasing the frequency or magnitude of reinforcement, should reduce pausing. Supporting data come from research with FR, FI, and VR schedules (e.g., Blakely & Schlinger, 1988;Crossman, 1971;Felton & Lyon, 1966;Griffiths & Thompson, 1973;Inman & Cheney, 1974; Killeen, 1969;Lowe & Harzem, 1977;Powell, 1968Powell, , 1969Rider & Kametani, 1984;Schlinger et al, 1990). For example, Powell (1969) studied reinforcement frequency by manipulating FR size; as frequency was increased (by lowering the FR), pausing was reduced.…”

Continuous Versus Discrete Dimensions of Reinforcement Schedules: An Integrative Analysis

“…Cumulative distance of wheel running (Skinner, 1938;Skinner & Morse, 1958); cumulative duration of lever holding (Rider & Kametani, 1984, 1987.…”

“…That is, reinforcement is typically contingent upon the occurrence of some specified number of discrete, easily repeatable responses that have been completed when the reinforcer is delivered, and reinforcing stimuli are usually presented on an all-or-none basis. However, contingencies may allow continuous response or reinforcer variation, as in the cumulative distance and duration schedules already described (Rider & Kametani, 1984, 1987Skinner & Morse, 1958).…”

“…The present model can accommodate alternatives to intermittent schedules based on response count. Ratio schedules may be defined as contingencies in which some amount of a dimension of the response class is required to produce some amount of a dimension of the consequence (Rider & Kametani, 1984, 1987. Any dimension of the response or the stimulus class may be inserted without destroying the essential nature of the ratio relation.…”