Rats engage in suboptimal choice when the delay to food is sufficiently long.

Abstract

Numerous examples in the decision-making literature demonstrate that animals sometimes make choices that are not in their long-term best interest. One particular example finds pigeons preferring a lowprobability alternative in lieu of a high-probability alternative, referred to as suboptimal choice. Although there is ample evidence that pigeons engage in such suboptimal choice, there is currently weak evidence (at best) that rats also do so. Cunningham and Shahan's (2018) temporal information-theoretic model suggests that suboptimal choice in pigeons arises when (1) the low-probability alternative provides stimuli that convey more temporal information than stimuli associated with the high-probability alternative and (2) when the delay to food is much longer relative to the delay to temporally informative signals at the choice point. The latter condition plays the important role of biasing decision making to be governed by the relative temporal information conveyed by stimuli rather than the relative rate of food delivery. The present experiment explored the possibility that rats will engage in suboptimal choice if the delay to food at the choice point is sufficiently long, as the temporal information-theoretic model suggests. Rats were given a choice between a suboptimal alternative providing food 20% of the time and an optimal alternative providing food 50% of the time. The suboptimal alternative provided stimuli that differentially signaled choice outcomes whereas the optimal alternative did not. The postchoice delay was manipulated across conditions and ranged from 10 s to 50 s. As with previous research, rats did not engage in suboptimal choice when the postchoice delay was 10 s. However, once the delay was at least 30 s, rats engaged in suboptimal choice. These results are consistent with the temporal informationtheoretic model of suboptimal choice and suggest that rats and pigeons likely do not differ in the decision-making processes involved in the suboptimal choice procedure.

The Δ–∑ hypothesis: How contrast and reinforcement rate combine to generate suboptimal choice

“…Part of the difficulty stems from the complexity of the task, from its large number of features including various stimuli, delays, and probabilities. Previous research has examined the role of, among other variables, the terminal link delays (which seem not to affect preference except when very short, for example, 1.5 s; see Cunningham & Shahan, ; Fortes et al, ; Kendall, ; Spetch et al, ; Zentall & Stagner, ); the degree of contiguity between choice and the terminal link stimulus onset (with gaps decreasing or reversing the preference for the suboptimal alternative; see McDevitt et al, ; Vasconcelos et al, ); and the response requirement during the initial links (VIs or FRs with parameter greater than 1 reduce or even prevent suboptimal behavior; see Fantino et al, ; Kendall, ; Zentall et al, ). However, most models of suboptimal choice rely on the predictability of the signals in the terminal link of the suboptimal alternative and the difference in the overall rate of reinforcement between alternatives (Cunningham & Shahan, ; Fortes et al, ; Stagner & Zentall, ).…”

Human and pigeon suboptimal choice

“…Since Kendall's (1974) initial demonstration, suboptimal choice has been extensively studied in pigeons (see McDevitt et al, 2016 andZentall, 2016b), and has been observed in monkeys (e.g., Blanchard, Hayden, & Bromberg-Martin, 2015;Bromberg-Martin & Hikosaka, 2009;Smith, Beran, & Young, 2017) and starlings (e.g., Vasconcelos, Monteiro, & Kacelnik, 2015). The procedure has also been used with rats, but the results have been less consistent (e.g., Mazur, 2007;Trujano & Orduna, 2015; but see Cunningham & Shahan, 2019). Human participants, however, have received little empirical attention despite the suggestion that the suboptimal choice task "provides a reasonable analog to human commercial gambling behavior" (Zentall, 2016a, p. 110, cf.…”

Human Choice Predicted by Obtained Reinforcers, Not by Reinforcement Predictors

“…Past research has demonstrated preference for an alternative which produces stimuli that signal the future presence or absence of reinforcement over an alternative which does not produce reinforcement-predictive stimuli. This preference has been found in multiple species, including capuchins, rhesus macaques, pigeons, and rats ( Roper and Zentall, 1999 ; Smith et al, 2017 ; Cunningham and Shahan, 2019 ; Smith and Beran, 2020 ). For example, when Roper and Zentall (1999) presented a choice between two alternatives which produced reinforcement equally 50% of the time, pigeons’ choices were more frequently allocated to the alternative which provided reinforcement-predictive stimuli (see Figure 1A ).…”

“…This choice preference has been found multiple times in pigeons ( Stagner and Zentall, 2010 ; Zentall and Stagner, 2011 ; Laude et al, 2014 ) and has been likened to gambling behavior demonstrated by humans ( Zentall, 2014 , 2016 ). The present experiments used a similarly structured task to examine adult human preferences for reinforcement predictors and compared findings to choice behavior demonstrated by children ( Lalli et al, 2000 ), monkeys ( Smith et al, 2017 ; Smith and Beran, 2020 ), dogs ( Jackson et al, 2020 ), rats ( Chow et al, 2017 ; Cunningham and Shahan, 2019 ; Jackson et al, 2020 ), and pigeons ( Roper and Zentall, 1999 ; Stagner and Zentall, 2010 ). In Experiment 1, adult human participants showed no preference for reinforcement predictors.…”