PREFERENCE FOR AND EFFECTS OF VARIABLE‐AS OPPOSED TO FIXED‐REINFORCER DURATION¹

Abstract

Pigeons were trained on multiple schedules in which a fixed number of pecks produced either a fixed or a variable period of access to food, the average variable-duration reinforcement equalling the fixed. Pecking rates were generally higher during the variableduration component. Subsequent performance on concurrent schedules revealed an initial preference for variable-duration reinforcement for all subjects; for most subjects, this preference was sustained. For one subject, the average variable duration was gradually reduced to half the fixed duration: continued preference for the variable component resulted in a loss of up to 30% of available reinforcement time. A return to multiple schedules with unequal pay-off shifted the preference to the greater fixed duration, and this preference was maintained even when the variable duration was again raised to equal the fixed duration. For the remaining subjects, the initial variable-duration preference on concurrent schedules was gradually replaced by a side preference. When the range of variable durations was varied, keeping the average variable duration equal to the fixed, the occasional longer reinforcers sustained a preference for variable-reinforcer durations for three of the four subjects.

The Science of Decision-making: Behaviours Related to Gambling

“…A majority of studies have found evidence that subjects are risk averse (Barkan, 1990;Battalio et al, 1985;Caraco, 1982;Caraco and Lima, 1985;Clements, 1990;Hamm and Shettleworth, 1987;Kagel et al, 1986;Logan, 1965;Menlove et al, 1979;Tuttle et al, 1990). However, several studies with nonhumans have found that subjects are risk prone or indifferent Bateson and Kacelnik, 1995;Essock and Reese, 1974;Mazur, 1985;Staddon and Innis, 1966;Young, 1981).…”

Incentive Theory: Iv. Magnitude of Reward

“…Such a modification, with a 3/1 weighting, reduces the average deviation to less than 5%. Essock and Reese (1974) gave pigeons a choice between two FR 30 schedules, one leading to 5-s access to grain and the other to a variable-duration access to grain. The subjects responded more on the key that produced fixedduration access.…”

Choice between variable and fixed cocaine injections in male rhesus monkeys

“…To date, there are no studies examining choice between fixed and variable doses of a drug reinforcer. When choice is between fixed and variable food amounts, results are mixed with different studies showing greater choice of a variable food amount and others showing aversion or indifference (e.g., Bateson and Kacelnik 1995; Essock and Reese 1974; Lagorio and Hackenberg 2012; McSweeney et al 2003; see Kacelnik and Bateson 1996 for a review).…”