Forced-exposure trials increase suboptimal choice

Do goldfish like to be informed?

Like humans, several mammalian and avian species prefer foretold over unsignalled future events, even if the information is costly and confers no direct benefit. It is unclear whether this is an epiphenomenon of basic associative learning mechanisms, or whether these preferences reflect a derived form of information-seeking that is reminiscent of human curiosity. We investigate whether a fish that shares basic reinforcement learning mechanisms with birds and mammals also shows such a preference, with the aim of elucidating whether widely shared conditioning processes are sufficient to explain paradoxical preferences resulting in unusable information. Goldfish (Carassius auratus) chose between two alternatives, both resulting in a 5 s delay and 50% reward chance. The 'informative' option immediately produced a stimulus correlated with the trial's forthcoming outcome (reward/no reward). Choosing the 'non-informative' option instead triggered an uncorrelated stimulus. Goldfish discriminated between the different contingencies but did not develop a preference for the informative option, suggesting that in goldfish associative learning mechanisms are not sufficient to generate preferences between alternatives differing only in outcome predictability. These results challenge the notion that informative preferences are a by-product of ubiquitous associative processes, and are consistent with the possibility that derived information-seeking mechanisms have evolved in some vertebrate species.

To know or not to know? Curiosity and the value of prospective information in animals

Humans and other animals often seek instrumental information to strategically improve their decisions in the present. Our curiosity also leads us to acquire non-instrumental information that is not immediately useful but can be encoded in memory and stored for use in the future by means of episodic recall. Despite its adaptive benefits and central role in human cognition, questions remain about the cognitive mechanisms and evolutionary origins that underpin curiosity. Here, we comparatively review recent empirical studies that some authors have suggested reflects curiosity in nonhuman animals. We focus on findings from laboratory tasks in which individuals can choose to gain advanced information about uncertain future outcomes, even though the information cannot be used to increase future rewards and is often costly. We explore the prevalence of preferences in these tasks across animals, discuss the theoretical advances that they have promoted, and outline some limitations in contemporary research. We also discuss several features of human curiosity that can guide future empirical research aimed at characterising and understanding curiosity in animals. Though the prevalence of curiosity in animals is actively debated, we surmise that investigating behavioural candidates for curiosity-motivated behaviour in a broader range of species and contexts, should help promote theoretical advances in our understanding of cognitive principles and evolutionary pressures that support curiosity-driven behaviour.

Temporal context effects on suboptimal choice

Choice can be driven both by rewards and stimuli that signal those rewards. Under certain conditions, pigeons will prefer options that lead to less probable reward when the reward is signaled. A recently quantified model, the Signal for Good News (SiGN) model, assumes that in the context of uncertainty, signals for a reduced delay to reward reinforce choice. The SiGN model provides an excellent fit to previous results from pigeons and the current studies are the first to test a priori quantitative predictions. Pigeons chose between a suboptimal alternative that led to signaled 20% food and an optimal alternative that led to 50% food. The duration of the choice period was manipulated across conditions in two experiments. Pigeons strongly preferred the suboptimal alternative at the shorter durations and strongly preferred the optimal alternative at the longer durations. The results from both experiments fit well with predictions from the SiGN model and show that altering the duration of the choice period has a dramatic effect in that it changes which of the two options pigeons prefer. More generally, these results suggest that the relative value of options is not fixed, but instead depends on the temporal context.

Human Behavior in Suboptimal Choice Tasks: Defining Optimality

Suboptimal choice behavior, or behavior that leads to a loss of resources over time, has been observed in a laboratory setting from multiple species. A procedure commonly used to capture this effect involves presenting two alternatives during choice trials, one of which is optimal whereas the other is suboptimal. The optimal alternative yields reinforcement more often than the suboptimal alternative, but often does not produce signals that indicate whether reinforcement will occur. The suboptimal alternative produces less reinforcement than the optimal alternative but may include reinforcement-predictive stimuli that indicate to the organism whether reinforcement will occur. This procedural framework has consistently produced a preference for the suboptimal alternative in pigeons and, to a lesser extent, rats. However, human participants have demonstrated preference for the optimal alternative. Following a review of past suboptimal choice research, we applied the reinforcement-derived definition of optimality to two sets of our previously published human data. We found that under multiple conditions, human choice behavior was consistent with what was predicted by the proportion of obtained reinforcement, thus supporting that the behavior was optimal. However, we found that participants in two conditions chose the suboptimal alternative more than expected. This finding could be considered as a demonstration of suboptimal choice in humans. We propose that comparing choice behavior to what past obtained reinforcement outcomes would predict might be a more accurate view of whether patterns of choice are within the parameters of this task.

Inhibition and paradoxical choice

The present study evaluated the role of inhibition in paradoxical choice in pigeons. In a paradoxical choice procedure, pigeons receive a choice between two alternatives. Choosing the "suboptimal" alternative is followed 20% of the time by one cue (the S+) that is always reinforced, and 80% of the time by another cue (S-) that is never reinforced. Thus, this alternative leads to an overall reinforcement rate of 20%. Choosing the "optimal" alternative, however, is followed by one of two cues (S3 or S4), each reinforced 50% of the time. Thus, this alternative leads to an overall reinforcement rate of 50%. González and Blaisdell (2021) reported that development of paradoxical choice was positively correlated to the development of inhibition to the S- (signal that no food will be delivered on that trial) post-choice stimulus. The current experiment tested the hypothesis that inhibition to a post-choice stimulus is causally related to suboptimal preference. Following acquisition of suboptimal preference, pigeons received two manipulations: in one condition one of the cues in the optimal alternative (S4) was extinguished and, in another condition, the S- cue was partially reinforced. When tested on the choice task afterward, both manipulations resulted in a decrement in suboptimal preference. This result is paradoxical given that both manipulations made the suboptimal alternative the richer option. We discuss the implications of our results, arguing that inhibition of a post-choice cue increases attraction to or value of that choice.

Commentary on Slocum et al. (2022): Additional Considerations for Evaluating Experimental Control

In the target article, Slocum et al. (2022) suggested that nonconcurrent multiple baseline designs can provide internal validity comparable to concurrent multiple baseline designs. We provide further support for this assertion; however, we highlight additional considerations for determining the relative strength of each design. We advocate for a more nuanced approach to evaluating design strength and less reliance on strict adherence to a specific set of rules because the details of the design only matter insofar as they help researchers convince others that the results are valid and accurate. We provide further support for Slocum et al.'s argument by emphasizing the relatively low probability that within-tier comparisons would fail to identify confounds. We also extend this logic to suggest that staggering implementation of the independent variable across tiers may be an unnecessary design feature in certain cases. In addition, we provide an argument that nonconcurrent multiple baseline designs may provide verification within baseline logic contrary to arguments made by previous researchers. Despite our general support for Slocum et al.'s assertions and our advocacy for more nuanced approaches to determining the strength of experimental designs, we urge experimenters to consider the perspectives of researchers from other fields who may favor concurrent multiple-baseline designs and suggest that using concurrent multiple-baseline designs when feasible may foster dissemination of behavior analytic research.