When good pigeons make bad decisions: Choice with probabilistic delays and outcomes

Abstract

Pigeons chose between an (optimal) alternative that sometimes provided food after a 10-s delay and other times after a 40-s delay and another (suboptimal) alternative that sometimes provided food after 10 s but other times no food after 40 s. When outcomes were not signaled during the delays, pigeons strongly preferred the optimal alternative. When outcomes were signaled, choices of the suboptimal alternative increased and most pigeons preferred the alternative that provided no food after the long delay despite the cost in terms of obtained food. The pattern of results was similar whether the short delays occurred on 25% or 50% of the trials. Shortening the 40-s delay to food sharply reduced suboptimal choices, but shortening the delay to no food had little effect. The results suggest that a signaled delay to no food does not punish responding in probabilistic choice procedures. The findings are discussed in terms of conditioned reinforcement by signals for good news.

Gambling-like behavior in pigeons: ‘jackpot’ signals promote maladaptive risky choice

“…Although there is a growing body of evidence to suggest that losses minimally influence preferences by pigeons 30, 34, 35 , translational procedures with rats have suggested that, if there is inhibition to loss signals, suboptimal choice does not occur 46 , and humans may show differential discounting of wins and losses 21, 22 . Although the lack of the ‘jackpot’ signal appearing on loss trials likely serves as a signal for a loss, we introduced a more salient signal for loss outcomes in the Signaled group to determine if salient losses would influence discount rates (see supplemental materials).…”

“…In this suboptimal choice procedure, choice of a gambling-like alternative is followed either by a signal indicating that a win or loss will follow, while the alternative choice generally results in an ambiguous, uninformative cue that provides greater overall reward 26 . It has been hypothesized that under these conditions pigeons over-weight the infrequent signal for wins 28, 29 , and show more optimal preferences if these signals are ambiguous 32, 33 ; conversely, pigeons also appear to under-weight the signal for losses 30, 31, 34, 35 , and show little change in choice when the salience of the loss is manipulated 30, 35 . Similar effects involving signaled outcomes may also be relevant to human risk taking, as Molet et al .…”

Suboptimal choice in rats: Incentive salience attribution promotes maladaptive decision-making

“…To our knowledge, the present study is the first to obtain suboptimal choice behavior in rats using a suboptimal choice procedure commonly used with pigeons (Pisklak et al 2015; McDevitt et al 2016; Zentall, 2016; Smith and Zentall, 2016; Smith et al 2016) and replicated with humans (Molet et al 2012). Importantly, like previous studies using lights as terminal-link stimuli to assess suboptimal choice behavior in rats using a similar procedure (Roper and Baldwin, 2004; Trujano and Orduna, 2015; Trujano et al 2016), we also demonstrated optimal choice behavior in rats when using lights as reward-associated stimuli.…”

“…Interestingly, previous research (Fantino, 1969; Moore, 1985; Dunn and Spetch, 1990; Williams and Dunn, 1991; Mazur, 1991, 1995, 1997; Williams, 1994; Roper and Zentall, 1999; Stagner et al 2012; Pisklak et al 2015; Smith and Zentall, 2016; Smith et al 2016) has suggested the importance of terminal-link stimuli as conditioned reinforcers and their ability to influence choice through various approaches. On the contrary, other approaches have been used that closely resemble the procedure used herein and have found contrasting results leading to different theories on the mechanisms that drive suboptimal choice behavior.…”

“…Thus, in the suboptimal choice procedure, the effects of primary reinforcement (i.e., food) can be dissociated from those of conditioned reinforcement, (the different stimuli in the terminal-links that predict reward). Using concurrent-chain schedules, there have been findings suggesting that terminal-link stimuli associated with reward outcome function as conditioned reinforcers and can influence the relative allocation of choices (Fantino, 1969; Moore, 1985; Dunn and Spetch, 1990; Williams and Dunn, 1991; Mazur, 1991, 1995, 1997; Williams, 1994; Roper and Zentall, 1999; Stagner et al 2012; Pisklak et al 2015; Smith and Zentall, 2016; Smith et al 2016), even if preference leads to significantly reduced primary reinforcement. Although not all stimuli associated with reward become conditioned reinforcers (cf.…”