Response acquisition with delayed reinforcement.

Abstract

Discrete responses of experimentally naive, food-deprived White Carneaux pigeons (key pecks) or Sprague-Dawley rats (bar or omnidirectional lever presses) initiated unsignaled delay periods that terminated with food delivery. Each subject first was trained to eat from the food source, but no attempt was made to shape or to otherwise train the response. In both species, the response developed and was maintained. Control procedures excluded the simple passage of time, response elicitation or induction by food presentation, type of operandum, food delivery device location, and adventitious immediate reinforcement of responding as the basis for the effects. Results revealed that neither training nor immediate reinforcement is necessary to establish new behavior. The conditions that give rise to both the first and second response are discussed, and the results are related to other studies of the delay of reinforcement and to explanations of behavior based on contingency or correlation and contiguity.

Neural systems implicated in delayed and probabilistic reinforcement

“…Delays can hamper both Pavlovian and instrumental conditioning (Dickinson, 1980(Dickinson, , 1994Gallistel, 1994;Hall, 1994;Mackintosh, 1983): for example, instrumental conditioning has long been observed to be systematically impaired as the outcome is delayed (Dickinson, Watt, & Griffiths, 1992;Grice, 1948;Harker, 1956;Lattal & Gleeson, 1990;Perin, 1943;Skinner, 1938). Despite this, normal rats have been shown to acquire free-operant responding with programmed response-reinforcer delays of up to 32 s, or even 64 s if the subjects are pre-exposed to the learning environment (Dickinson et al, 1992).…”

Perceived intent motivates people to magnify observed harms

“…However, a rat that has been made cocaine-dependent, and is therefore motivated to obtain the drug, will often choose to expend effort to obtain cocaine, even when otherwise appetitive food is available. This change in free-choice behavior is an example of a motivational shift in what the rat wants and how their new motivations shape their behavioral priorities [similar motivational shifts occur as a result of conditioning, surgery, genetic modification, and other manipulations (36)(37)(38)(39)]. …”

“…Following this logic, participants in Exp. 2 completed a reinforcement game modeled after classic studies of animal motivation (36)(37)(38)(39)(40). In a typical experiment of this type, the number of times that a rat pressed a lever indexed the rat's motivation to obtain a food reward associated with that lever (such that hungry rats would demonstrate greater effort and persistence in lever-pressing than nonhungry rats).…”

Acquisition of discriminated operant responding: The effects of brief reinforcement delays

“…Thus, little is known about the effects of delays on the acquisition of discriminated responding under free-operant, multiple schedule conditions. A number of researchers (Bruner et aI., 1998;Dickinson, Watt, & Griffiths, 1992;Lattal & Gleeson, 1990;Lattal & Metzger, 1994;Skinner, 1938;Van Haaren, 1992) have investigated response acquisition with delays to reinforcement; the current experiments parametrically investigated the acquisition of discriminated responding under nonresetting (Experiment 1 a) and resetting delays (Experiments 1 b, 2a, and 2b).…”

“…In his first experiment, however, Skinner used a resetting variable delay that averaged 2, 4, 6, and 8 s; while in the second, acquisition experiment, he used nonresetting fixed delays of 1, 2, 3, and 4 s. In the latter case, he noted that the procedure allowed for intervals between responses and reinforcers that were shorter than those prescribed by the experiment. Lattal and Gleeson (1990) and Wilkenfield, Nickel, Blakely, and Poling (1992) corrected for many of the procedural limitations in Skinner (1938) and demonstrated response acquisition in the absence of explicit shaping using resetting, nonresetting, and stacked delays. Dews (1960) demonstrated that nonresetting delays maintained higher rates of responding than resetting delays using pigeons and FR-1 schedules with delays of 10 s, 30 s, or 100 s. However, as Skinner noted, responses during the delay interval were likely in the nonresetting delay case, whereas those responses would have been punished under contingencies of resetting delays.…”