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.

Suboptimal choice: A review and quantification of the signal for good news (SiGN) model.

As first reported several decades ago, pigeons (Columba livia) sometimes choose options that provide less food over options that provide more food. This behavior has been variously referred to as suboptimal, maladaptive, or paradoxical because it lowers overall food intake. A great deal of research has been directed at understanding the conditions under which animals and people make suboptimal choices and the mechanisms that drive this behavior. Here, we review the literature on suboptimal choice and the variables that play a role in this phenomenon. Suboptimal choice is most likely to occur when the outcomes following a choice are uncertain, when the outcomes are delayed after the choice, and when the outcomes are signaled only on the option that provides food less often. We propose a mathematical formalization of the signal for good news (SiGN) model which assumes that a signal for a reduction in delay to food reinforces choice. We generate predictions from the model about the effect of parameters that characterize suboptimal choice and we show that, even in the absence of free parameters, the SiGN model provides a very good fit to the choice proportions of birds from a large set of conditions across studies from numerous researchers. R code for SiGN predictions and the data set are available on the Open Science Framework (https://osf.io/39qtj). We discuss limitations of the model, propose directions for future research, and discuss the general applicability of this research to understanding how rewards and signals for reward may combine to reinforce behavior. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Directed retreat and navigational mechanisms in trail following Formica obscuripes.

Ant species exhibit behavioural commonalities when solving navigational challenges for successful orientation and to reach goal locations. These behaviours rely on a shared toolbox of navigational strategies that guide individuals under an array of motivational contexts. The mechanisms that support these behaviours, however, are tuned to each species' habitat and ecology with some exhibiting unique navigational behaviours. This leads to clear differences in how ant navigators rely on this shared toolbox to reach goals. Species with hybrid foraging structures, which navigate partially upon a pheromone-marked column, express distinct differences in their toolbox, compared to solitary foragers. Here, we explore the navigational abilities of the Western Thatching ant (Formica obscuripes), a hybrid foraging species whose navigational mechanisms have not been studied. We characterise their reliance on both the visual panorama and a path integrator for orientation, with the pheromone's presence acting as a non-directional reassurance cue, promoting continued orientation based on other strategies. This species also displays backtracking behaviour, which occurs with a combination of unfamiliar terrestrial cues and the absence of the pheromone, thus operating based upon a combination of the individual mechanisms observed in solitarily and socially foraging species. We also characterise a new form of goalless orientation in these ants, an initial retreating behaviour that is modulated by the forager's path integration system. The behaviour directs disturbed inbound foragers back along their outbound path for a short distance before recovering and reorienting back to the nest.

Route retracing: way pointing and multiple vector memories in trail-following ants.

Maintaining positional estimates of goal locations is a fundamental task for navigating animals. Diverse animal groups, including both vertebrates and invertebrates, can accomplish this through path integration. During path integration, navigators integrate movement changes, tracking both distance and direction, to generate a spatial estimate of their start location, or global vector, allowing efficient direct return travel without retracing the outbound route. In ants, path integration is accomplished through the coupling of pedometer and celestial compass estimates. Within path integration, it has been theorized navigators may use multiple vector memories for way pointing. However, in many instances, these navigators may instead be homing via view alignment. Here, we present evidence that trail-following ants can attend to segments of their global vector to retrace their non-straight pheromone trails, without the confound of familiar views. Veromessor pergandei foragers navigate to directionally distinct intermediate sites via path integration by orienting along separate legs of their inbound route at unfamiliar locations, indicating these changes are not triggered by familiar external cues, but by vector state. These findings contrast with path integration as a singular memory estimate in ants and underscore the system's ability to way point to intermediate goals along the inbound route via multiple vector memories, akin to trapline foraging in bees visiting multiple flower patches. We discuss how reliance on non-straight pheromone-marked trails may support attending to separate vectors to remain on the pheromone rather than attempting straight-line shortcuts back to the nest.

Rare and extreme outcomes in risky choice.

Many real-world decisions involving rare events also involve extreme outcomes. Despite this confluence, decisions-from-experience research has only examined the impact of rarity and extremity in isolation. With rare events, people typically choose as if they underestimate the probability of a rare outcome happening. Separately, people typically overestimate the probability of an extreme outcome happening. Here, for the first time, we examine the confluence of these two biases in decisions-from-experience. In a between-groups behavioural experiment, we examine people's risk preferences for rare extreme outcomes and for rare non-extreme outcomes. When outcomes are both rare and extreme, people's risk preferences shift away from traditional risk patterns for rare events: they show reduced underweighting for events that are both rare and extreme. We simulate these results using a small-sample model of decision-making that accounts for both the underweighting of rare events and the overweighting of extreme events. These separable influences on risk preferences suggest that to understand real-world risk for rare events we must also consider the extremity of the outcomes.

Varieties of visual navigation in insects.

The behaviours and cognitive mechanisms animals use to orient, navigate, and remember spatial locations exemplify how cognitive abilities have evolved to suit a number of different mobile lifestyles and habitats. While spatial cognition observed in vertebrates has been well characterised in recent decades, of no less interest are the great strides that have also been made in characterizing and understanding the behavioural and cognitive basis of orientation and navigation in invertebrate models and in particular insects. Insects are known to exhibit remarkable spatial cognitive abilities and are able to successfully migrate over long distances or pinpoint known locations relying on multiple navigational strategies similar to those found in vertebrate models-all while operating under the constraint of relatively limited neural architectures. Insect orientation and navigation systems are often tailored to each species' ecology, yet common mechanistic principles can be observed repeatedly. Of these, reliance on visual cues is observed across a wide number of insect groups. In this review, we characterise some of the behavioural strategies used by insects to solve navigational problems, including orientation over short-distances, migratory heading maintenance over long distances, and homing behaviours to known locations. We describe behavioural research using examples from a few well-studied insect species to illustrate how visual cues are used in navigation and how they interact with non-visual cues and strategies.

Biased confabulation in risky choice.

When people make risky decisions based on past experience, they must rely on memory. The nature of the memory representations that support these decisions is not yet well understood. A key question concerns the extent to which people recall specific past episodes or whether they have learned a more abstract rule from their past experience. To address this question, we examined the precision of the memories used in risky decisions-from-experience. In three pre-registered experiments, we presented people with risky options, where the outcomes were drawn from continuous ranges (e.g., 100-190 or 500-590), and then assessed their memories for the outcomes experienced. In two preferential tasks, people were more risk seeking for high-value than low-value options, choosing as though they overweighted the outcomes from more extreme ranges. Moreover, in two preferential tasks and a parallel evaluation task, people were very poor at recalling the exact outcomes encountered, but rather confabulated outcomes that were consistent with the outcomes they had seen and were biased towards the more extreme ranges encountered. This common pattern suggests that the observed decision bias in the preferential task reflects a basic cognitive process to overweight extreme outcomes in memory. These results highlight the importance of the edges of the distribution in providing the encoding context for memory recall. They also suggest that episodic memory influences decision-making through gist memory and not through direct recall of specific instances.

Forced-exposure trials increase suboptimal choice.

The influence of single option or forced-exposure (FE) trials was studied in the suboptimal choice task. Pigeons chose between an optimal alternative that led to food half of the time and a suboptimal alternative that led to food 20% of the time. Choice of the suboptimal alternative was compared across groups of subjects that received different numbers of FE trials during training. In Experiment 1, subjects received 100% FE trials, 67% FE trials, or only choice trials. Pigeons in the two groups that had FE trials developed extreme preference for the signaled suboptimal alternative over the unsignaled optimal alternative, while pigeons that had no FE trials showed pronounced individual differences. Experiment 2 compared 10% and 90% FE trials. When neither alternative signaled trial outcomes, both groups of subjects strongly preferred the optimal alternative. When the suboptimal alternative provided differential signals, the subjects in the 90% FE group developed strong preference for the suboptimal alternative and subjects in the 10% FE group maintained preference for the optimal alternative. The results of both experiments demonstrate that FE trials can have substantial effects on the development of preference in the suboptimal choice task.

Aversive view memories and risk perception in navigating ants.

Many ants establish foraging routes through learning views of the visual panorama. Route models have focused primarily on attractive view use, which experienced foragers orient towards to return to known sites. However, aversive views have recently been uncovered as a key component of route learning. Here, Cataglyphis velox rapidly learned aversive views, when associated with a negative outcome, a period of captivity in vegetation, triggering increases in hesitation behavior. These memories were based on the accumulation of experiences over multiple trips with each new experience regulating forager hesitancy. Foragers were also sensitive to captivity time differences, suggesting they possess some mechanism to quantify duration. Finally, we analyzed foragers' perception of risky (i.e. variable) versus stable aversive outcomes by associating two sites along the route with distinct captivity schedules, a fixed or variable duration, with the same mean across training. Foragers exhibited fewer hesitations in response to risky outcomes compared to fixed ones, indicating they perceived risky outcomes as less severe. Results align with a logarithmic relationship between captivity duration and hesitations, suggesting that aversive stimulus perception is a logarithm of its actual value. We discuss how aversive view learning could be executed within the mushroom bodies circuitry following a prediction error rule.

Good news is better than bad news, but bad news is not worse than no news.

Under certain conditions, pigeons will reliably prefer an alternative that leads to a lower probability of food over an alternative that leads to a higher probability of food (i.e., demonstrate suboptimal choice). A critical aspect of the typical procedure is that the alternative associated with less food provides differential stimuli that signal trial outcomes, but the alternative associated with more food does not. Few studies have investigated how partial signaling of an alternative influences preference. In Experiments 1-3, pigeons chose between two alternatives that each led to food 60% of the time with partially signaled trial outcomes. One alternative occasionally provided a stimulus that always preceded food (i.e., "good news") and the other alternative occasionally provided a stimulus that always preceded no food ("bad news"). Experiments 2 and 3 also assessed preference in conditions in which alternatives were either completely unsignaled (provided no differential stimuli) or always led to food. Pigeons consistently preferred the "good news" alternative over the "bad news" alternative and preferred 100% food over the "bad news" alternative. The results from conditions in which pigeons chose between the "bad news" alternative and an unsignaled alternative were inconclusive, but suggestive of a preference for bad news. The results are used to evaluate and distinguish between competing explanations of suboptimal choice.

Encoding Context Determines Risky Choice.

Both memory and choice are influenced by context: Memory is enhanced when encoding and retrieval contexts match, and choice is swayed by available options. Here, we assessed how context influences risky choice in an experience-based task in two main experiments (119 and 98 participants retained, respectively) and two additional experiments reported in the Supplemental Material available online (152 and 106 participants retained, respectively). Within a single session, we created two separate contexts by presenting blocks of trials in distinct backgrounds. Risky choices were context dependent; given the same choice, people chose differently depending on other outcomes experienced in that context. Choices reflected an overweighting of the most extreme outcomes within each local context rather than the global context of all outcomes. When tested in the nontrained context, people chose according to the context at encoding and not retrieval. In subsequent memory tests, people displayed biases specific to distinct contexts: Extreme outcomes from each context were more accessible and judged as more frequent. These results pose a challenge for theories of choice that rely on retrieval as guiding choice.

Role of the pheromone for navigation in the group foraging ant, Veromessor pergandei.

Navigation is comprised of a variety of strategies which rely on multiple external cues to shape a navigator's behavioral output. Here, we explored in the ant Veromessor pergandei, the interactions between the information provided by the pheromone trail and the home vector guided by the celestial compass. We found that a cross sensory interaction between the pheromone cue and the path integrator underlies correct orientation during the inbound journey. The celestial compass provides directional information, while the presence of the trail pheromone acts as a critical context cue, triggering distinct behaviors (vector orientation, search, and backtracking). While exposed to the pheromone, foragers orient to the vector direction regardless of vector state, while in the pheromone's absence, the current remaining vector determines the forager's navigational behavior. This interaction also occurs in foragers with no remaining path integrator, relying on the activation of a celestial compass-based memory of the previous trip. Such cue interactions maximize the foragers' return to the nest and inhibit movement off the pheromone trail. Finally, our manipulations continuously rotated foragers away from their desired heading, yet foragers were proficient at counteracting these changes, steering to maintain a correct compass heading even at rotational speeds of ~ 40°/s.

Traveling through light clutter: Path integration and panorama guided navigation in the Sonoran Desert ant, Novomessor cockerelli.

Foraging ants use multiple navigational strategies, including path integration and visual panorama cues, which are used simultaneously and weighted based upon context, the environment and the species' sensory ecology. In particular, the amount of visual clutter in the habitat predicts the weighting given to the forager's path integrator and surrounding panorama cues. Here, we characterize the individual cue use and cue weighting of the Sonoran Desert ant, Novomessor cockerelli, by testing foragers after local and distant displacement. Foragers attend to both a path-integration-based vector and the surrounding panorama to navigate, on and off foraging routes. When both cues were present, foragers initially oriented to their path integrator alone, yet weighting was dynamic, with foragers abandoning the vector and switching to panorama-based navigation after a few meters. If displaced to unfamiliar locations, experienced foragers travelled almost their full homeward vector (∼85 %) before the onset of search. Through panorama analysis, we show views acquired on-route provide sufficient information for orientation over only short distances, with rapid parallel decreases in panorama similarity and navigational performance after even small local displacements. These findings are consistent with heavy path integrator weighting over the panorama when the local habitat contains few prominent terrestrial cues.

Pheromone cue triggers switch between vectors in the desert harvest ant, Veromessor pergandei.

The desert harvester ant (Veromessor pergandei) employs a mixture of social and individual navigational strategies at separate stages of their foraging trip. Individuals leave the nest along a pheromone-based column, travelling 3-40 m before spreading out to forage individually in a fan. Foragers use path integration while in this fan, accumulating a direction and distance estimate (vector) to return to the end of the column (column head), yet foragers' potential use of path integration in the pheromone-based column is less understood. Here we show foragers rely on path integration both in the foraging fan and while in the column to return to the nest, using separate vectors depending on their current foraging stage in the fan or column. Returning foragers displaced while in the fan oriented and travelled to the column head location while those displaced after reaching the column travel in the nest direction, signifying the maintenance of a two-vector system with separate fan and column vectors directing a forager to two separate spatial locations. Interestingly, the trail pheromone and not the surrounding terrestrial cues mediate use of these distinct vectors, as fan foragers briefly exposed to the pheromone cues of the column in isolation altered their paths to a combination of the fan and column vectors. The pheromone acts as a contextual cue triggering both the retrieval of the column-vector memory and its integration with the forager's current fan-vector.

Effects of winning cues and relative payout on choice between simulated slot machines.

BACKGROUND AND AIMS: Cues associated with winning may encourage gambling. We assessed the effects on risky choice of slot machine of: (1) neutral sounds paired with winning, (2) casino-related cues (such as the sound of coins dropping and pictures of dollar signs) and (3) relative payouts. DESIGN: Experimental studies in which participants repeatedly chose between safer and riskier simulated slot machines. Safer slot machines paid the same amount regardless of which symbols lined up. Risky machines paid different amounts depending on which symbols lined up. Effects of initially neutral sounds paired with the best payout were assessed between-groups (experiment 1a) and within-participants (experiment 1b). In experiment 2, pairing of casino-related audiovisual cues with payout was assessed within participants, and cue timing was assessed between groups. SETTING: A university research laboratory in Edmonton, Canada. PARTICIPANTS: Undergraduate students (n = 630 across three experiments). MEASUREMENTS: Preference for riskier over safer machines, preference between machines that differed in cues, payout recall and frequency estimates for payouts. Risky choice was calculated as the proportion of choices of the risky machine when presented with a fixed machine of the same expected value. FINDINGS: In experiment 1a, risky choice was slightly increased by pairing a sound with the best payout compared with pairing the sound with a lower payout (P = 0.04, d = 0.28) but not compared with no sound [P = 0.36, d = 0.13, Bayes factors (BF)10  = 0.22]. In experiment 1b, people did not prefer a machine with a best-payout sound over one with a lower-payout sound (P = 0.67, d = 0.03, BF10  = 0.11). Relative payout affected choice: risky choices were higher for high- than low-payout decisions (P < 0.001, d = 0.53). In experiment 2, people preferred machines with casino-related cues paired with winning (P < 0.001, r2  = 0.11) and cue timing (at choice or concurrently with the win) had no effect (P = 0.95, r2  = 0.0, BF10  = 0.05). Casino-related cues also enhanced payout memory (P = 0.013 and 0.006). Cue effects were not specific to risk: people also preferred fixed-payout machines with casino-related cues (P < 0.001, r2  = 0.16). CONCLUSIONS: In a gambling simulation, student participants chose more risky slot machines when payouts were relatively higher and when casino-related cues were associated with payouts. Pairing a neutral sound with the best payout did not consistently affect slot machine choice, and the effect of casino cues did not depend on their timing. Casino-related cues enhanced payout memory.

The Near-Miss Effect in Slot Machines: A Review and Experimental Analysis Over Half a Century Later.

In games of chance, a near miss is said to occur when feedback for a loss approximates a win. For instance, obtaining "cherry-cherry-lemon" on a slot machine could be considered a near miss. Sixty-six years ago, B.F. Skinner first proposed the idea that near-miss events might reinforce continued play in slot machines, and despite some inconsistencies in the experimental literature, belief in this "near-miss effect" has remained strong. In the present manuscript, we will review this literature and present experimental assessments of the near-miss effect on the frequency of the gambling response. Experiment 1 used a tightly controlled resistance-to-extinction procedure in pigeons to evaluate the putative reinforcing effect of near misses relative to a control "far-miss" reel pattern. Experiment 2 extended Experiment 1's procedure to human participants. The results of both experiments failed to support the near-miss effect hypothesis. Experiment 3 used a further simplified procedure to assess the validity of the resistance-to-extinction paradigm when a probable conditional reinforcer was present on the reel stimuli. Although a clear conditional response was obtained from the reel, subsequent testing in extinction revealed no conditionally reinforcing function of this stimulus on operant response frequency.

Suboptimal choice and initial-link requirement.

Pigeons (n = 14) were trained in a concurrent-chains suboptimal choice procedure that tested the effect of an increased ratio requirement in the initial links. Fixed-ratio 1 and 25 conditions were manipulated within subjects in a counterbalanced order. In all conditions, distinct terminal-link stimuli on a suboptimal alternative signaled either primary reinforcement (20% of the time) or extinction (80% of the time). On an optimal alternative, two distinct terminal-link stimuli each signaled a 50% chance of primary reinforcement. Preference for the suboptimal alternative was significantly attenuated, and in some birds completely reversed, by the larger response requirement irrespective of condition order. This larger response requirement also generated a notable increase in between-subject variability. A measure of cumulative choice responding is introduced to mitigate the problems associated with traditional session averages. Ordinal predictions of some current theories of suboptimal choice are also considered in light of the results.

Same but different: Socially foraging ants backtrack like individually foraging ants but use different mechanisms.

Diverse species may adopt behaviourally identical solutions to similar environmental challenges. However, the underlying mechanisms dictating these responses may be quite different and are often associated with the specific ecology or habitat of these species. Foraging desert ants use multiple strategies in order to successfully navigate. In individually foraging ants, these strategies are largely visually-based; this includes path integration and learned panorama cues, with systematic search and backtracking acting as backup mechanisms. Backtracking is believed to be controlled, at least in solitary foraging species, by three criteria: 1) foragers must have recent exposure to the nest panorama, 2) the path integrator must be near zero, and 3) the ant must be displaced to an unfamiliar location. Instead of searching for the nest, under these conditions, foragers head in the opposite compass direction of the one in which they were recently travelling. Here, we explore backtracking in the socially foraging desert harvester ant (Veromessor pergandei), which exhibits a foraging ecology consisting of a combination of social and individual cues in a column and fan structure. We find that backtracking in V. pergandei, similar to solitary foraging species, is dependent on celestial cues, and in particular on the sun's position. However, unlike solitary foraging species, backtracking in V. pergandei is not mediated by the same criteria. Instead the expression of this behaviour is dependent on the presence of the social cues of the column and the proportion of the column that foragers have completed prior to displacement.