Does precrastination explain why some observers are suboptimal in a visual search task?

How do we decide where to search for a target? Optimal search relies on first considering the relative informational value of different locations and then executing eye movements to the best options. However, many participants consistently move their eyes to locations that can be easily ascertained to neither contain the target nor provide new information about the target's location. Here, we asked whether this suboptimal search behaviour represents a specific example of a general tendency towards precrastination: starting sub-goals of a task before they are needed, and in so doing, spending longer time on doing the task than is necessary. To test this hypothesis, we asked 200 participants to do two tasks: retrieve two heavy buckets (one close and one far) and search for a line segment. Precrastination is defined as consistently picking up the closer bucket first, versus the more efficient strategy of picking up the farther bucket first. Search efficiency is the proportion of fixations directed to more cluttered regions of the search array. Based on the pilot data, we predicted an association of precrastination with inefficient search strategies. Personality inventories were also administered to identify stable characteristics associated with these strategies. In the final dataset, there was no clear association between search strategy and precrastination, nor did these correlate strongly with any of the personality measures collected. This article received in-principle acceptance (IPA) at Royal Society Open Science on 29 January 2020. The accepted Stage 1 version of the manuscript, not including results and discussion, may be found at https://osf.io/p2sjx. This preregistration was performed prior to data collection and analysis.

What makes the ephemeral reward task so difficult?

The ephemeral reward task involves providing subjects with a choice between two distinctive stimuli, A and B, each containing an identical reward. If A is chosen, the reward associated with A is obtained and the trial is over. If B is chosen, the reward associated with B is obtained but A remains, and the reward associated with A can be obtained as well. Thus, the reward-maximizing solution is to choose B first. Although cleaner fish (wrasse) and parrots easily acquire the optimal response by choosing B, paradoxically, several nonhuman primate species, as well as rats and pigeons, do not. It appears that some species do not associate their choice and reward with the second reward. Surprisingly, research in an operant context with pigeons and rats suggests that inserting a delay between the choice and reward facilitates optimal choice. It is suggested that impulsivity may be, in part, responsible for the difficulty of the task. In an attempt to better understand this task, we trained human subjects on an operant version of this task, with and without a brief delay between choice and reward and found that many subjects failed to learn to choose optimally, independent of the delay. Furthermore, performance on this task was not correlated with a task thought to measure impulsivity, the Balloon Analog Risk Task or with the Abbreviated Impulsivity Survey. We concluded that, for humans, the task is confusing because there is no incorrect response, only good and better, and better is not easily discriminated. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Serial pattern learning: The anticipation of worsening conditions by pigeons.

In general, animals are known to be sensitive to the immediacy of reinforcers. That is, they are generally impulsive and outcomes that occur in the future are generally heavily discounted. Furthermore, they should prefer alternatives that provide reinforcers that require less rather than greater effort to obtain. In the present research, pigeons were given a choice between (1) obtaining reinforcers on a progressively more difficult schedule of reinforcement; starting with four pecks, then eight pecks, then 16 pecks, then 32 pecks, and finally 64 pecks on each trial, and (2) a color signaling a number of pecks for a single reinforcer: red = six, green = 11, blue = 23, or yellow = 45. If pigeons choose optimally, most of the time they should choose the progressive schedule to obtain five reinforcers rather than switch to a color to receive only one. However, if they are sensitive primarily to the number of pecks to the next reinforcer, they should choose the progressive schedule once before switching to red, twice before switching to green, three times before switching to blue, and four times before switching to yellow. Instead, they systematically switched too early. Rather than choose based on the rate of reinforcement or even based on the time or effort to the next reinforcer, they appear to anticipate that the progressive schedule is going to get more difficult, and they base their choice suboptimally on the serial pattern of the worsening progressive schedule.

How language and agriculture promote culture- and peace-promoting norms.

Humans are predisposed to form in-groups and out-groups that are remarkably flexible in their definition due largely to the complex language that has evolved in them. Language has allowed for the creation of shared "background stories" that can unite people who do not know each other. Second, the discovery of agriculture has resulted in the critical need to negotiate boundaries, a process that can lead to peace (but also war).

Conditional discrimination learning by pigeons: Stimulus-response chains or occasion setters?

In conditional discrimination, the conditional stimulus or sample indicates which of two choice or comparison stimuli is associated with a reinforcer. Two hypotheses have been proposed concerning the role of the sample stimulus. According to Hull (1952), the sample and the response to the correct comparison form a stimulus-response chain. According to Skinner (1938), however, the sample serves as an occasion setter, setting the occasion for the choice of the correct comparison stimulus. In a conditional discrimination, if the sample stimulus forms part of a stimulus-response chain, then presenting the sample in the absence of the comparison stimuli should weaken the association. If the sample serves as an occasion setter, however, presenting the sample alone should not weaken its occasion-setting ability. In two experiments we tested these predictions. In Experiment 1, following conditional discrimination training with vertical and horizontal line samples and red and green comparison stimuli, we found that the presentation of the samples without the comparison stimuli (followed sometimes by a reinforcer) had little effect on conditional discrimination accuracy. In Experiment 2, two different houselights served as samples. When we presented the samples without comparison stimuli and without the reinforcers we found similar results. The results support the hypothesis that in conditional discrimination, the samples serve as occasion setters. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Memory for where and when: pigeons use single-code/default strategy.

Memory for what, where, and when an event took place has been interpreted as playing a critical role in episodic memory. Moreover, such memory is likely to be important to an animal's ability to efficiently forage for food. In Experiment 1 of the present study, pigeons were trained on a task in which on each trial, one lit stimulus color and location was presented and then another. A cue presented after the last stimulus location signaled that the pigeon was to choose either the first location presented, or the last location presented, to receive a reinforcer. After learning this task, in Experiment 2, the color cue was removed, requiring the pigeons to choose based on location and order alone. In Experiment 3, when a delay was inserted between presentation of the two locations, it had little effect on task accuracy. Results suggested that the pigeons had acquired the task using a single-code/default rule. When presented with the cue indicating that the last location was correct, pigeons selected the location just presented. When presented with the cue indicating that the first location was correct, pigeons chose the other location, by default. In support of this hypothesis, in Experiment 4, when a delay was inserted, prior to receiving the instructional cue, it had a disruptive effect on task accuracy proportional to the delay. Although the present results do not provide evidence for episodic memory, they do suggest that the pigeons have developed a single-code/default strategy that appears to be an efficient means of performing this task.

Interference of same/different learning by a spatial discrimination.

Same/different learning by pigeons has long been of interest to experimental psychologists. In one of these procedures, matching-to-sample, responses to a sample stimulus result in the presentation of two comparison stimuli, one of which matches the sample, the other of which does not, and choice of the matching stimulus is reinforced. Evidence of a matching concept has been found when transfer has been found to new stimuli. Given the transfer results, it is surprising that acquisition of two matching tasks (or two mismatching tasks), has not been found to be any faster than one matching and one mismatching task (i.e., two compatible tasks do not appear to facilitate each other). In the present experiment, we asked if matching acquisition involving three colors would be retarded if the correct response to a fourth color was not matching but was spatial (e.g., if the sample is red choose the red comparison, if the sample is green choose the green comparison, if the sample is yellow choose the yellow comparison, but if the sample is blue choose the left comparison). We found that acquisition of this task was slower than acquisition of a four color matching task (i.e., when the sample was blue, the blue comparison was correct). The results suggest that there is an interaction among matching associations, such that common rules facilitate learning compared with having to learn an inconsistent (spatial) rule. This result provides further evidence of the development of a matching concept by pigeons.

What enables "distraction" to reduce delay discounting for pigeons (Columba livia).

In a successive delay-discounting task, a small reward can be obtained immediately but a larger reward can be obtained if one waits. There is evidence that the larger reward can be obtained more easily if one is "distracted" from obtaining the small reward. It is proposed here that a distractor stimulus may function as a Pavlovian conditioned stimulus (sign tracking) because orienting to it may be directly associated with the larger reinforcer. In the present study with pigeons, we examined two successive procedures: (a) a peck to a red light resulted in one pellet of food, and waiting for the red light to turn off resulted in five pellets (Red-Only). (b) If the pigeon pecked a red light, it received one pellet of food, and if it waited for the red light to turn to green, a peck to the green light resulted in five pellets of food (Red-Green). For both groups, on some trials, a concurrent (distractor) stimulus appeared with the red light but responses to it had no programed consequence. Results indicated that the pigeons in both groups waited for the larger reward more often when the distractor was present than when it was absent and that pigeons in the Red-Only group waited longer than those in the Red-Green group. The results are consistent with the hypothesis that the concurrent stimulus served as a conditioned stimulus for the Red-Only group and as a higher order conditioned stimulus for the Red-Green group. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Implicit learning of the one-back reinforcement matching-mismatching task by pigeons.

Humans can learn tasks explicitly, as they can often describe the rules they have used to learn the task.1,2,3 Animals, however, are thought to learn tasks implicitly (i.e., purely associatively).2,3 That is, they gradually learn the correlation or association between the stimulus (or response) and the outcome. Both humans and pigeons can learn matching, where a sample stimulus indicates which one of two stimuli matches the sample. The 1-back reinforcement task is a difficult version of matching in which a correct response on trial N is rewarded only following a response on trial N + 1 (independent of the response on trial N + 1),4 and the correct response on trial N + 1 indicates whether a reward will occur on trial N + 2, and so forth. Humans do not appear to be able to learn the 1-back rule.5 Pigeons, however, do show 1-back reinforcement learning,6,7 and they appear to do so implicitly by gradually learning the correlation between their response on one trial and the outcome on the next trial (because all other relations are uncorrelated with the outcome). They learn the task slowly and to a level below what would be expected had they learned it explicitly. The present results, together with research with humans,7 suggest that there are times when human explicit learning may interfere with the ability of humans to learn. Pigeons, however, are not "distracted" by attempts at explicit learning, and thus they are able to learn this and other similar tasks.6,7,8.

Comparative Cognition Research Demonstrates the Similarity between Humans and Other Animals.

The field of comparative cognition represents the interface between the cognitive behavior of humans and other animals. In some cases, research demonstrates that other animals are capable of showing similar cognitive processes. In other cases, when animals show behavior thought to be culturally determined in humans, it suggests that simpler processes may be involved. This review examines research primarily with pigeons (out of convenience because of their visual ability). I start with the concept of sameness and follow with the concept of stimulus equivalence, the building blocks of human language. This is followed by research on directed forgetting, the cognitive ability to maintain or forget information. A hallmark of cognition is transitive inference performance (if A < B, and B < C, the understanding that A < C), but the variety of species that show this ability suggests that there may be simpler accounts of this behavior. Similarly, experiments that demonstrate a form of cognitive dissonance in animals suggest that dissonance may not be necessary to explain this biased behavior. Furthermore, examples of sunk cost in pigeons suggests that the human need to continue working on a failing project may also have a biological basis. Finally, pigeons show a preference for a suboptimal choice that is similar to unskilled human gambling, a finding that may clarify why humans are so prone to engage in this typically losing activity.

"Distractor" effects in delay discounting of probability by pigeons.

Impulsive behavior can be measured by performance on a successive delay-discounting task, in which a response to a stimulus provides a small reinforcer sooner (SS), but in the absence of a response, a larger reinforcer later (LL). Previous research suggests that the presence of a concurrent "distractor" stimulus, to which responding has no programed consequence, can result in increased LL reinforcers. In the present experiments, we used differences in the probability of reinforcement between SS and LL (rather than magnitude of reinforcement) and tested the hypothesis that the concurrent stimulus may become a Pavlovian conditioned stimulus. For the Red-Only group, a response to the SS stimulus resulted in a reinforcer with a low probability (SS), whereas the absence of a response resulted in a reinforcer with a high probability (LL). For the Red-Green group, (analogous to the more typical simultaneous choice between an SS and LL stimulus) the absence of a response to the SS stimulus replaced the SS stimulus with the LL stimulus and a response to the LL stimulus resulted in the reinforcer. Thus, for the Red-Green group, the concurrent stimulus should have been less effective because responding to the concurrent stimulus was not immediately followed by the reinforcer. In Experiment 1, the concurrent stimulus was a yellow key-light; in Experiment 2, it was a houselight. In both experiments, the concurrent stimulus was effective in increasing the number of LL reinforcers and the effect was larger for the Red-Only group than for the Red-Green group.

1-Back reinforcement symbolic-matching by humans: How do they learn it?

For humans, a distinction has been made between implicit and explicit learning. Implicit learning is thought to involve automatic processes of the kind involved in much Pavlovian conditioning, while explicit learning is thought to involve conscious hypothesis testing and rule formation, in which the subject's statement of the rule has been taken as evidence of explicit learning. Various methods have been used to determine if nonverbal animals are able to learn a task explicitly - among these is the 1-back reinforcement task in which feedback from performance on the current conditional discrimination trial is provided only after completion of the following trial. We propose that it is not whether an organism can learn the task, but whether they learn it rapidly, all-or-none, that provides a better distinction between the two kinds of learning. We had humans learn a symbolic matching, 1-back reinforcement task. Almost half of the subjects failed to learn the task, and of those who did, none described the 1-back rule. Thus, it is possible to learn this task without learning the 1-back rule. Furthermore, the backward learning functions for humans differ from those of pigeons. Human subjects who learned the task did so all-or-none, suggesting explicit learning. In earlier research with pigeons, they too showed significant learning of this task; however, backward learning functions suggested that they did so gradually over the course of several sessions of training and to a lower level of asymptotic accuracy than the humans, a result suggesting implicit learning was involved.

Pigeons learn two matching tasks, two nonmatching tasks, or one of each.

When pigeons learn matching-to-sample or nonmatching-to-sample there is good evidence that they can transfer that learning to novel stimuli. But early evidence suggests that in the rate of task acquisition, there is no benefit from a matching relation between the sample and the correct or incorrect comparison stimulus. In the present research we trained three groups of pigeons, each on two two-stimulus tasks simultaneously, matching-matching, nonmatching-nonmatching, or matching-nonmatching. If a common matching or nonmatching relationship benefits acquisition, the first two groups should acquire their tasks faster than the third group, for which the two tasks ought to be incompatible. The results indicated that all three groups acquired their tasks at about the same rate. A secondary goal of the experiment was to determine the basis of learning for the each of the three groups. During testing, for each task, there were test trials in which one of the stimuli from the other task replaced either the correct or the incorrect comparison stimulus. Surprisingly, neither comparison stimulus appeared to show complete control over comparison choice. Although replacing either comparison stimulus resulted in a decrement in task accuracy from about 90% to 70% correct, independent of which comparison stimulus was replaced, the pigeons chose correctly at well above chance accuracy. Suggestions to explain this unexpected outcome are discussed.

Matching is acquired faster than mismatching by pigeons when salient stimuli are presented manually.

Same/different learning by pigeons has been studied using several different procedures. One of these procedures is matching-to-sample or mismatching-from-sample in which responses to a sample stimulus result in the presentation of two comparison stimuli, one of which matches the sample, the other of which does not. In the matching task, choice of the matching stimulus is reinforced. In the mismatching task, choice of the stimulus that does not match the sample is reinforced. Most research that has compared acquisition of the two tasks has not reported a difference between them. Research with transfer of training, in which either the matching stimulus or the mismatching stimulus is replaced with a new stimulus, suggests that the matching stimulus is selected in the matching task, but the matching stimulus is rejected in the mismatching task. In the present experiment, pigeons were trained on either matching or mismatching with salient stimuli presented manually and the reinforcer was presented under a colored slide that covered it. In Phase 1 with a noncorrection procedure and a reinforcer for pecking the sample, pigeons did not acquire either task, however, in Phase 2 they learned both tasks readily without reinforcement for pecking the sample and with a correction procedure. Furthermore, the pigeons learned matching significantly faster than mismatching, suggesting that sameness may be a more natural stimulus relation than mismatching.

Is there a need to distinguish instrumental copying behavior from traditions?

The authors make a distinction between instrumental copying behavior in which there is a clear reward for the copying behavior and social copying (traditions) in which the rewards for copying are less clear. However, I see no reason to distinguish between the two. We are social animals, for whom copying traditions have important rewards, those of affiliation.

Biases and suboptimal choice by animals suggest that framing effects may be ubiquitous.

Framing effects attributed to "quasi-cyclical" irrational complex human preferences are ubiquitous biases resulting from simpler mechanisms that can be found in other animals. Examples of such framing effects vary from simple learning contexts, to an analog of human gambling behavior, to the value added to a reinforcer by the effort that went into obtaining it.

Flexible learning of matching and mismatching by pigeons.

When pigeons learn a conditional discrimination in which a sample stimulus indicates which of two comparison stimuli is correct Skinner (1950) proposed that they learn a chain involving the sample, the correct comparison stimulus, and the reinforcer. This implies that they do not learn to reject the incorrect comparison stimulus and the sameness relation between the sample and the correct or the incorrect comparison stimulus plays little role in learning. There is, however, considerable evidence that learning to match or mismatch the sample can transfer to novel stimuli. But there is little evidence that the sameness relation facilitates acquisition. In the present research, pigeons were trained on two 0-s delay conditional discriminations: two matching tasks, two mismatching tasks, or one of each. No differences were found in acquisition, suggesting that consistent matching or mismatching does not facilitate acquisition of conditional discriminations. In testing, when either the correct or the incorrect comparison stimulus in each discrimination was replaced with one of the stimuli from the other task, results suggested that when learning both tasks, the pigeons in all three groups had learned both to select the correct stimulus and to reject the incorrect stimulus. It appears that the pigeons may have had learned the tasks based on sample/comparison-stimulus configurations with the sample serving as an occasion setter.

Pigeon's choice depends primarily on the value of the signal for the outcome rather than its frequency or contrast.

Pigeons typically prefer a 20% probability of signaled reinforcement over a 50% probability of unsignaled reinforcement. There is even evidence that they prefer 50% signaled reinforcement over 100% reinforcement. It has been suggested that this effect results from contrast between the expected probability of reinforcement (e.g., 50%) at the time of choice and the value of the positive signal for reinforcement (100%). Alternatively, it is primarily the value of the positive signal for reinforcement itself that determines suboptimal choice. To attempt to distinguish between these two hypotheses, in Experiment 1, we gave pigeons a choice between (a) a 50% reinforcement alternative that was followed by one of two signals for 100% reinforcement, each 25% of the time, or a signal for the absence of reinforcement 50% of the time (50% contrast) and (b) a 25% reinforcement alternative that was followed by a signal for 100% reinforcement 25% of the time, or a signal for the absence of reinforcement 75% of the time (75% contrast). In spite of the difference in contrast, the pigeons were indifferent between the two alternatives. In Experiment 2, when contrast was held constant at 50% and the value of the positive signals for reinforcement were different, we found support for choice based on the value of the positive signal for reinforcement. Thus, it appears that pigeons' choice depends primarily on the value of the outcome rather than its frequency or contrast. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Pavlovian processes may produce contrast leading to bias and suboptimal choice.

Pavlovian processes are likely responsible for the varied contexts in which contrast occurs between what is expected and what is obtained. Such contrast effects result in paradoxical biases and even suboptimal choice by animals. For example, pigeons prefer a suboptimal alternative that results in a stimulus signaling a low probability (20%) high reward (ten pellets) over an optimal alternative that results in a stimulus signaling a high probability (100%) of a smaller reward (three pellets). This effect is analogous to human unskilled gambling. In another case, pigeons prefer a stimulus that has required many pecks to obtain over one the has required one peck to obtain (a so-called justification of effort effect). In a third line of research that investigated the preference for risky choice over safe choice, pigeons chose between two alternatives, a safe choice that resulted in two pellets of food, or a risky choice that resulted in either one or three pellets of food. In general, the pigeons preferred the risky alternative, but importantly, their choice was influenced by whether the choice reflected a gain or a loss - the difference between what was shown to them (one, two, or three pellets) and what they received. Each of these lines of research suggest the importance of contrast effects produced by Pavlovian processes that result in biases or suboptimal behavior.

Decision making under risk: framing effects in pigeon risk preferences.

When humans face probabilistic outcomes, their choices often depend on whether the choice is framed in terms of losses or gains. In the present research, we gave pigeons a choice between risky (variable) outcomes and safe (constant) outcomes that resulted in the same net reward. In Experiment 1, in which the outcomes represented a loss, the pigeons preferred the risky alternative. In Experiment 2, in which the outcomes represented a gain, the pigeons were indifferent between the two alternatives. In Experiment 3, in which the outcomes represented neither a gain nor a loss, the pigeons strongly preferred the risky alternative. The results were interpreted in terms of the relative value of gains and losses given to the alternatives by pigeons in the context of a risky and safe choice. In Experiment 4 we tested that hypothesis by giving pigeons a choice between a risky and safe alternative with the same net outcome, in the context of a gain associated with the safe alternative, but no gain or loss associated with the risky alternative. In support of the interpretation of the first three experiments, with the safe alternative associated with a gain, the pigeons now preferred the safe alternative. These results were discussed in terms of economic and foraging theories and were contrasted with the aversion to uncertainty (risk) more typically shown by humans.