Latent inhibition refers to the observation, made in both human and nonhuman animals, that learning about the relationship between a stimulus and an outcome progresses more rapidly when the stimulus is novel compared to when the stimulus has been rendered familiar by preexposure. Three experiments with human participants show that this effect can be reversed to reveal faster learning about a familiar than a novel stimulus, by manipulating the novelty/familiarity of the experimental context. In each experiment, during Stage 1, a preexposed stimulus was rendered familiar by being repeatedly presented within a stream of distractor letters that constituted the experimental context. In a subsequent training stage, participants were required to respond to a target outcome that was preceded by the familiar stimulus on some trials and a novel stimulus on others. These trials were also presented within a stream of contextual distractor stimuli. The results showed that during the training stage, learning about the familiar stimulus proceeded more successfully than the novel stimulus when the distractor stimuli sustained novelty during training (Experiments 1-3), but that this effect could be reverted to latent inhibition when the distractor stimuli sustained familiarity during training (Experiments 2 and 3). The results are in keeping with a novelty-mismatch analysis of latent inhibition, and a novelty-mediated generalization explanation of the results is proposed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

In three experiments, participants were asked to mentally count how many target stimuli appeared in a sequence of presentations, without informing them that there were two types of stimuli (AX and BX) with a specific difference. Some participants received intermixed AX and BX presentations (INT groups), while others received the presentations in blocks (BLK groups). In all three experiments, the INT group showed a greater ability to differentiate the stimuli in a posttest compared to the BLK group. In Experiment 1a, where AX and BX were drawings of plants that differed in the number of petals, the improvement in differentiation was accompanied by the ability to identify the specific difference. However, in Experiments 1b and 2, where AX and BX were robots with a more subtle difference in eye separation, the improvement in differentiation occurred without participants being able to indicate what the difference between the stimuli was. These results suggest that intermixed preexposure can generate, without the need for initial instructions to look for differences between stimuli, both explicit (Experiment 1a) and implicit (Experiments 1b and 2) beneficial effects on stimulus differentiation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Separating and isolating the contributions of perception to concept formation in animals has been a long-standing and persistent challenge. Here we describe a novel approach to assessing this question by using equivalence training consisting of unrelated images as the basis for subsequent same/different (S/D) learning. Following equivalence class training, two groups of pigeons attempted to learn a go/no-go discrimination task constructed from these classes. In the go/no-go task, a consistent group was given an S/D assignment that aligned with this prior training (same vs. different classes). An inconsistent group was given go/no-go assignments that were misaligned with their established classes. The consistent group exhibited better learning and stimulus control in their S/D task than did the inconsistent group. These results suggest that pigeons can use trained properties derived from class-based information to learn an S/D task without the aid of perceptual similarity. This novel approach holds promise for helping to evaluate the contribution of perceptual similarity to different types of concept learning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

In two experiments, participants completed two computer-based tasks: a configural acquired equivalence procedure and an optional-shift procedure. Both revealed that test performance was positively correlated, even when controlling for nonspecific variables. This finding supports the suggestion that a common mechanism underlies performance in both tasks. Experiment 2 included eye tracking to the stimuli used in the task. We found that participants who attended to the predictive compound elements in the optional-shift training went on to show stronger attentional-set effects in the subsequent test. The relationship between attention and performance is considered by reference to attentional and nonattentional learning theories. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

In Pavlovian conditioning, the strength of a conditioned response is a function of the probability of reinforcement. However, manipulations of probability are often confounded with changes in the rate of reinforcement. Two between-group experiments in mice evaluated the effect of the probability of reinforcement, while controlling the rate of reinforcement, on appetitive conditioning and extinction. Experiment 1 equated the reinforcement rate by manipulating the number of reinforcements received in each reinforced trial in a critical group (one vs. two consecutive rewards). The results of this experiment showed that probability influenced the rate of responses in acquisition, even when controlling the reinforcement rate. Experiment 2 further assessed the role of probability on behavior while controlling the rate of reinforcement during the conditioned stimulus (CS) using a split-trial design, in which the total CS time was held constant but presented in different numbers of discrete trials (e.g., 50% reinforcement with two 12 s CS's vs. 100% reinforcement with a 24 s average CS duration). This experiment confirmed that probability influenced response rates, and both the probability and rate of reinforcement affected the proportion of trials with responses. Together, these results suggest that the probability of reinforcement, while having little effect on the speed at which responses emerged, affects responding even when the rate of reinforcement is held constant. The results challenge formal learning theories to account for the effects of both the probability and rate of reinforcement. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The expression of an association between a conditioned stimulus (CS) and an unconditioned stimulus (US) can be attenuated by presenting the CS by itself (i.e., extinction, Ext). Though effective, Ext is susceptible to recovery effects such as renewal, spontaneous recovery, and reinstatement. Dunsmoor et al. (2015, 2019) have proposed that pairing the CS with a neutral outcome (novelty-facilitated Ext [NFE]) could offer better protection against recovery effects than Ext. Though NFE has been compared to Ext, it has rarely been compared to counterconditioning (CC), a similar procedure except that the CS is paired with a US having a valence opposite to the US used in initial training. We report two aversive conditioning experiments using the rapid-trial streaming procedure with human participants that compare the efficacies and susceptibilities to ABA renewal of Ext, CC, and NFE. Associative learning was assessed through expectancy learning and evaluative conditioning. CC and NFE equally decreased anticipation of the US in the presence of the CS (i.e., expectancy learning). Depending on how the CS-US association was probed, they were either as or more effective at doing so than Ext. All three interference treatments were equally susceptible to context manipulations. Only CC clearly altered the valence of the CS (i.e., evaluative conditioning). Valence ratings after Ext, CC, and NFE, as well as a no-interference control condition, were all equally susceptible to context effects. Overall, the present study does not support the assertion that NFE is consistently more resistant to recovery effects than Ext. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Elemental models of associative learning typically employ a common prediction-error term. Following a conditioning trial, they predict that the change in the strength of an association between a cue and an outcome is dependent upon how well the outcome was predicted. When multiple cues are present, they each contribute to that prediction. The same rule applies both to increases in associative strength during excitatory conditioning and the loss of associative strength during extinction. In five experiments using an allergy prediction task, we tested the involvement of a common error term in the extinction of causal learning. Two target cues were each paired with an outcome prior to undergoing extinction in compound either with a second excitatory cue or with a cue that had previously undergone extinction in isolation. At test, there was no difference in the causal ratings of the two target cues. Manipulations designed to bias participants toward elemental processing of cue compounds, to promote the acquisition of inhibitory associations, or to reduce generalization decrement between training and test were each without effect. These results are not consistent with common error term models of associative learning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Our theory of positively reinforced free-operant behavior (Perez & Dickinson, 2020) assumes that responding is controlled by two systems. One system is sensitive to the correlation between response and reinforcement rates and controls goal-directed behavior, whereas a habitual system learns by reward prediction error. We present an extension of this theory to the aversive domain that explains why free-operant avoidance responding increases with both the experienced rate of negative reinforcement and the difference between this rate and that programmed by the avoidance schedule. The theory also assumes that the habitual component is reinforced by the acquisition of aversive inhibitory properties by the feedback stimuli generated by responding, which then act as safety signals that reinforce habit performance. Our analysis suggests that the distinction between habitual and goal-directed control of rewarded behavior can also be applied to the aversive domain. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Latent inhibition is said to occur when learning about the relationship between a cue and an outcome proceeds more readily when the cue is novel relative to when the cue has been rendered familiar through mere preexposure. Previous studies suggest that latent inhibition, while evident in 4- to 5-year-old children, is attenuated or even absent in older children. There are, however, acknowledged shortcomings associated with previous demonstrations of this effect, which we attempted to overcome using a letter prediction task that has been employed in recent studies of latent inhibition in adults. One hundred and seventy-five 4- to 14-year-old children and 175 young adults completed a letter prediction task, with a latent inhibition manipulation embedded within it. Using developmental trajectory analysis we found, contrary to other studies, an increase in the magnitude of latent inhibition as children age, with the effect becoming significant when children were around 6.7 years of age. Model comparison revealed that a linear function best described the relationship between latent inhibition and age. We discuss these findings in the context of theories of learning and attention, and consider the role of concurrent task type as a factor that determines the developmental trajectory of latent inhibition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The ABA renewal effect occurs when behavior is trained in one context (A), extinguished in a second context (B), and the test occurs in the training context (A). Two mechanisms that explain ABA renewal are context summation at the test and contextual modulation of extinction learning, with the former being unlikely if both contexts have a similar associative history. In two experiments, we used within-subjects designs in which participants learned to avoid a loud noise (unconditioned stimulus) signaled by discrete visual stimuli (conditioned stimuli [CSs]), by pressing the space bar on the computer keyboard. The training was conducted in two contexts, with a different pair of CSs (CS+ and CS-) trained in each context. During extinction, CS+ and CS- stimuli were presented in the alternative context from that of training, and participants were allowed to freely respond, but no loud noise was presented. Finally, all CSs were tested in both contexts, resulting in a within-subjects ABA versus ABB comparison. Across experiments, participants increased avoidance responses during training and decreased them during extinction, although Experiment 2 revealed less extinction. During the test, responding was higher when CS+ were tested in the training context (ABA) versus the extinction context (ABB), revealing the renewal of instrumental avoidance. Experiment 2 also measured expectancy after the avoidance test and revealed a remarkable similarity between avoidance responses and expectancy ratings. This study shows the renewal of instrumental avoidance in humans, and the results suggest the operation of a modulatory role for the context in renewal, similar to the occasion setting of extinction learning by the context. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Four experiments examined human ratings of causal effectiveness, and ability to detect causal relationships, in a nonverbal paradigm. Participants responded on a concurrent random interval, extinction schedule. In the presence of one stimulus, responses produced an outcome (triangle flash); in the presence of the other stimulus, they did not. Following making a judgment of causal effectiveness, two further stimuli were presented simultaneously with one another, and participants had to select one depending on which of the previous two stimuli were associated with effective responses. In all experiments, immediate outcomes were associated with higher causal ratings and better causal detection than outcomes delayed by 3 s. A signal inserted between response and outcome improved ratings and detection (Experiments 2 and 4), even when it was contiguous with the response but not the outcome (Experiments 2 and 3). Stimuli associated with both components (marking cues) did not impact judgments or detection (Experiment 3). Stimuli signaling the availability of an outcome if a response was made (signaled reinforcement) did not improve causal judgments, but did improve detection of stimuli associated with the outcome (Experiment 4). Responses during the delay interfered with detection of the actual relationship when delays were unsignaled (Experiments 1-4), but not with fully or briefly signaled delays (Experiments 2-4), or with signaled reinforcement (Experiment 4). The results suggest a delay stimulus serves to signal the response has been successful and demark the delay period by serving a discriminative function. These findings mirror those seen in nonhuman conditioning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neophobia and neophilia can be lifesaving as they can facilitate foraging while avoiding predation or intoxication. We investigated the extent to which Goffin's cockatoos () exhibit ecollogically relevant and quantifiable neophobic responses toward specific object properties. Twelve cockatoos were presented with 12 novel objects grouped into four distinct categories with unique features: size, color, reflective capacity, and shape. The cockatoos were tested by measuring their latency to approach a high-quality food reward for both novel and control scenarios. Age and sex did not affect the latency to approach food in the presence of a novel object in this species. Additionally, we found no significant differences between the objects of the reflective and color categories. This result is likely due to the plasticity of neophobic behavior related to the benefits and costs of approaching novel stimuli. The cockatoos were significantly slower to approach food in the presence of objects larger than their body size than objects of a similar or smaller size, a phenomenon possibly explained by the increased risk of approaching unknown objects large enough to be a potential predator. They were also significantly more hesitant to approach food in the presence of elongated objects, a phenomenon potentially explained by an ecologically relevant avoidance of snakes. The extent of this neophobia was statistically similar at a group level, indicating that avoidance of elongated and large objects could be an adaptive response aiding survival under natural circumstances and that snakes may impose strong selective pressures on this species. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Rescorla (2000, 2001) interpreted his compound test results to show that both common and individual error terms regulate associative change such that the element of a conditioned compound with the greater prediction error undergoes greater associative change than the one with the smaller prediction error. However, it has recently been suggested that uncertainty, not prediction error, is the primary determinant of associative change in people (Spicer et al., 2020, 2022). The current experiments use the compound test in a continuous outcome allergist task to assess the role of uncertainty in associative change, using two different manipulations of uncertainty: outcome uncertainty (where participants are uncertain of the level of the outcome on a particular trial) and causal uncertainty (where participants are uncertain of the contribution of the cue to the level of the outcome). We replicate Rescorla's compound test results in the case of both associative gains (Experiment 1) and associative losses (Experiment 3) and then provide evidence for greater change to more uncertain cues in the case of associative gains (Experiments 2 and 4), but not associative losses (Experiments 3 and 5). We discuss the findings in terms of the notion of theory protection advanced by Spicer et al., and other ways of thinking about the compound test procedure, such as that proposed by Holmes et al. (2019). (PsycInfo Database Record (c) 2024 APA, all rights reserved).

According to the cycle/trial (C/T) rule, the rate of associative learning is a function of the ratio between the overall rate of U.S. presentation (C) and its rate in the presence of the conditioned stimulus (CS; [T]). This rule is well supported in studies with nonhumans. The present study was conducted to test whether it also applies to human contingency learning. In Experiment 1, participants were exposed to rapid streams of trials. Sensitivity to the cue-outcome contingency varied with both intertrial interval (ITI, which captures C) and cue duration, but the C/T rule was not respected, notably because the effect of ITI was much larger than the effect of cue duration. Experiment 2 showed that mere suppression of verbal strategies did not alter the magnitude of the ITI effect. Experiment 3 replicated Experiment 1 but with cue duration and ITI varied between 1,000 and 3,000 ms instead of between 100 and 1,000 ms. Performance was insensitive to both cue duration and ITI. This was not the consequence of Experiment 3 only varying the cue duration to ITI ratio by a factor of 3; in Experiment 4 where the cue duration was 100 ms, a 300-ms ITI was sufficient to observe an ITI effect. The lack of an ITI effect with a 1,000-ms cue and an ITI varying between 1,000 and 3,000 ms was replicated in Experiment 5. These results are discussed in light of how processes underlying associative learning might break down when events occur very rapidly. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Taste aversion learning has sometimes been considered a specialized form of learning. In several other conditioning preparations, after a conditioned stimulus (CS) is conditioned and extinguished, reexposure to the unconditioned stimulus (US) by itself can reinstate the extinguished conditioned response. Reinstatement has been widely studied in fear and appetitive Pavlovian conditioning, as well as operant conditioning, but its status in taste aversion learning is more controversial. Six taste-aversion experiments with rats therefore sought to discover conditions that might encourage it there. The results often yielded little to no evidence of reinstatement, and we also found no evidence of concurrent recovery, a related phenomenon in which responding to a CS that has been conditioned and extinguished is restored if a second CS is separately conditioned. However, a key result was that reinstatement occurred when the conditioning procedure involved multiple closely spaced conditioning trials that could have allowed the animal to learn that a US presentation signaled or set the occasion for another trial with a US. Such a mechanism is precluded in many taste aversion experiments because they often use very few conditioning trials. Overall, the results suggest that taste aversion learning is experimentally unique, though not necessarily biologically or evolutionarily unique. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Two experiments observed an effect consistent with a latent-inhibition (LI) effect in humans that (a) did not depend on masking or instruction-generated expectations and (b) suggested that the effect results from a change in processing of the predictive cue. Participants viewed a video of a superhero character flying through three different contexts past a different stimulus in each context. In conditioning, The superhero flew past a target cue that was either Novel (Group No Exposure), had been preexposed in the Same context as where conditioning was occurring (Group Same), or was preexposed in a Different context (Group Different). Each time the superhero flew past the target cue his Hands Glowed (outcome). On test (E1), an image of the superhero flying in the context with normal Hands and the target cue was present. Participants were asked if anything was missing. Experiment 2 tested participants with the superhero present and his Hands Glowing to test outcome-cue associations (Test 1) or just the superhero in the context (Test 2, counterbalanced) to assess contextual associations. In E1 fewer people in Group Same reported the outcome missing than Group No Exposure or Group Different. In E2 fewer people in Group Same reported the target cue missing when presented with the outcome than in the other groups, a result inconsistent with interference accounts of LI. When presented only with contextual cues, reports of the stimulus missing showed that the context was associated with the stimuli presented within it. Results are discussed with respect to theories and demonstrations of human LI. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

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).

If a conditioned stimulus or response has been inconsistently ("partially") reinforced, conditioned responding will take longer to extinguish than if responding had been established by consistent ("continuous") reinforcement. This partial reinforcement extinction effect (PREE) is one of the best-known phenomena in associative learning but defies ready explanation by associative models which assume that a partial reinforcement schedule will produce weaker conditioning that should be less resistant to extinction. The most popular explanation of the PREE is that, during partial reinforcement, animals learn that recent nonreinforced (N) trials are associated with subsequent reinforcement (R), and therefore the presence of N trials during extinction serves to promote generalization of conditioning to extinction. According to sequential theory (Capaldi, 1966), animals can encode whole sequences (runs) of N trials and associate their memory of the sequence with subsequent R. The length of these N sequences during conditioning affects how long the animal will continue to respond during extinction. The present experiment used Pavlovian magazine approach conditioning with rats to test two predictions of this theory. Consistent with sequential theory, the PREE was sensitive to the length of the N sequence: conditioning with long sequences (runs of 3-5 N trials) produced a stronger PREE than conditioning with short sequences (runs of 1 or 2) even when the total number of N and R trials was held constant. Surprisingly, there was no PREE among rats trained with the short sequences. Moreover, contrary to the theory's prediction, interrupting the long N sequences with reinforced trials of a different conditioned stimulus did not affect the subsequent PREE. I conclude that uncertainty about reinforcement, rather than the memory of N sequences per se, is a key factor in the development of the PREE. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Three experiments examined the effect of instructions on human free-operant performance on random ratio (RR) and random interval (RI) schedules. Both rates of responding, and the microstructure of behavior, were explored to determine whether bout-initiation and within-bout responding may be controlled by different processes. The results demonstrated that responding in acquisition (Experiments 1 and 2) and extinction (Experiment 3) was impacted in line with given instructions. During acquisition, rates were higher on RR compared to RI for accurate and minimal instructions. During extinction, rates decreased when there were minimal instructions. However, instructions had a greater impact on within-bout responding, than they did on bout-initiation responding. Overall rates of responding, and within-bout rates, varied in line with the nature of the instructions, but bout-initiation responding did not (Experiments 1 and 2). Resistance to extinction was increased by instructions in terms of overall responding and within-bout rates, but not in terms of bout-initiation rates (Experiment 3). These data are consistent with the hypothesis that bout-initiation responding may be less impacted by instructions than within-bout responding, speculatively, the former is stimulus-driven, automatic/habitual, and less accessible to conscious processing. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The partial reinforcement extinction effect (PREE) refers to the phenomenon that conditioned responding extinguishes more slowly if subjects had been inconsistently ("partially") reinforced than if they had been reinforced on every trial ("continuously" reinforced). One largely successful account of the PREE, known as sequential theory (Capaldi, 1966), suggests that, when subjects are partially reinforced, they learn that memories of sequences of nonreinforced trials are associated with subsequent reinforcement. This association helps to maintain responding (i.e., delay extinction) when the subjects experience nonreinforced trials during extinction. Sequential theory's explanation of the PREE hinges on subjects learning sequences of nonreinforced trials during acquisition. However, direct evidence for such sequential learning is not available in previous studies of the PREE where animals are trained with multiple sequences of different lengths that are randomly intermixed and, therefore, cannot anticipate whether a given trial will be reinforced during acquisition. The current study conducted two experiments that trained rats with a single fixed trial sequence to provide evidence of sequential learning during conditioning, and then observe its effect on the PREE. Under one condition the rats did learn about the fixed sequence but did not subsequently show a PREE, whereas other rats that did show a PREE had not learned the trial sequences during conditioning. Therefore, contrary to sequential theory's prediction, our result suggests that learning about the trial sequence is neither necessary nor sufficient for the PREE. We suggest that the PREE may instead depend on uncertainty about whether the conditioned stimulus will be reinforced. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A series of experiments employed a specific Pavlovian-instrumental transfer (PIT) task in rats to determine the capacity of various treatments to undermine two outcome-specific stimulus-outcome (S-O) associations. Experiment 1 tested a random treatment, which involved uncorrelated presentations of the two stimuli and their predicted outcomes. This treatment disrupted the capacity of the outcome-specific S-O associations to drive specific PIT. Experiment 2 used a negative-contingency treatment during which the predicted outcomes were exclusively delivered in the absence of their associated stimulus. This treatment spared specific PIT, suggesting that it left the outcome-specific S-O associations relatively intact. The same outcome was obtained in Experiment 3, which implemented a zero-contingency treatment consisting of delivering the predicted outcomes in the presence and absence of their associated stimulus. Experiment 4 tested a mixed treatment, which distributed the predicted outcomes at an equal rate during each stimulus. This treatment disrupted the capacity of the outcome-specific S-O associations to drive specific PIT. We suggest that the mixed treatment disrupted specific PIT by generating new and competing outcome-specific S-O associations. By contrast, we propose that the random treatment disrupted specific PIT by undermining the original outcome-specific S-O associations, indicating that these associations must be retrieved to express specific PIT. We discuss how these findings inform our theoretical understanding of the mechanisms underlying this phenomenon. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Four experiments in human predictive learning evaluated whether the extinction makes the acquisition context specific (EMACS) effect is attenuated when the increase in prediction error that extinction produces disappears. Participants had to evaluate the relationship between a given food (cue) that was ingested by an imaginary client of a given restaurant (context) and a potential gastric illness (outcome). The task was implemented using Gorilla online software. All participants received the relevant training in context A, and equivalent exposure to context B. Cue E was presented paired with the outcome in all groups. Cue E was then either extinguished (group E) or not extinguished (group NE), either previously or concurrently to training of the target cue (P). P was then tested in contexts A and B. When extinction was conducted concurrently, performance to P became context-dependent regardless of the number of extinction trials (12 or 24)-the EMACS effect. The EMACS effect disappeared when extinction was elongated to 24 trials, and conducted before acquisition of P. Implications of these results for attentional explanations of context processing are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Reports an error in "Modulating perceptual learning indexed by the face inversion effect: Simulating the application of transcranial direct current stimulation using the MKM model" by Ciro Civile, Rossy McLaren, Charlotte Forrest, Anna Cooke and Ian P. L. McLaren (, 2023[Jul], Vol 49[3], 139-150). The article is being made available open access under the CC-BY license under the Jisc/ APA Read and Publish agreement. The correct copyright is "© 2023 The Author(s)" and the CC-BY license disclaimer is below. The online version of this article has been corrected. (The following abstract of the original article appeared in record 2023-90030-001). We report here two large studies investigating the effects of an established transcranial direct current stimulation (tDCS) procedure on perceptual learning as indexed by the face inversion effect. Experiments 1a and 1b (n = 128) examined the harmful generalization from Thatcherized faces to normal faces by directly comparing the size of the inversion effect for normal faces when presented intermixed with Thatcherized faces (Experiment 1a) versus that obtained when normal faces were presented intermixed with checkerboards (Experiment 1b). The results from the sham/control tDCS groups provide the first direct evidence in the literature showing how Thatcherized faces generalize onto normal ones producing a reduced inversion effect compared to when normal faces are presented with stimuli (e.g., checkerboards) that do not generalize significantly to normal faces. In the anodal tDCS groups, this effect was reversed, with a larger inversion effect recorded for normal faces in Experiment 1a versus that found in Experiment 1b. Further analyses within each experiment confirmed that the anodal tDCS procedure can enhance the inversion effect for normal faces in circumstances where harmful generalization would otherwise be produced by the Thatcherized faces (Experiment 1a). We also demonstrated our standard reduction in the inversion effect for normal faces consequent on the application of tDCS when presented intermixed with stimuli that do not generalize onto them. We interpret our results in terms of simulations using the MKM model of perceptual and associative learning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Three experiments with rats explored whether previously extinguished goal-directed and habitual responding recover with the same status using an ABA renewal preparation. In Experiments 1a and 1b, a lever-press response was minimally (four sessions) or extensively (16 sessions) trained in one context (Context A) and extinguished in another context (Context B). Then, outcome devaluation took place in either Context A or Context B in which a food pellet reinforcing the response was paired with lithium chloride (LiCl) for devalued groups and with saline for a control group. Finally, renewal of the extinguished response was tested in both Contexts A and B. We confirmed that both minimally and extensively trained responses renewed as goal-directed action regardless of the context in which devaluation took place. This finding was replicated in Experiment 2 even after more extended acquisition training (32 sessions). However, another group that received outcome devaluation before but not after extinction training showed habitual performance during extinction training as well as in a subsequent renewal test. Experiment 3 replicated these results and confirmed that renewal of goal direction for rats that received extinction training immediately prior to outcome devaluation was not an artifact of consecutive LiCl exposures over a short period of time in Experiments 1 and 2, using a more reliable devaluation protocol. Overall, the present results extend previous findings suggesting that actions and habits renew with the same status by returning to the original context after extinction. The most critical finding is the differential effects of pre- and postextinction devaluation on the expression of habitual behavior; extinction prior to devaluation may convert a habitual performance into a goal-directed action. This novel finding is discussed in relation to recent studies that identified several factors contributing to a transition from habitual to goal-directed control of instrumental behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Pavlovian conditioning has been proven to be useful for the study of associative learning and animal cognition. This procedure can be used to observe certain memory phenomena. The appetitive conditioning of several neutral stimuli can result in higher response rates, and therefore a better memory, for the first and last stimuli of the series. This is equivalent to primacy and recency effects. In this work, the tentacle lowering procedure was employed to study these phenomena in the snail (). Subjects experienced five odorous conditioned stimuli (CS) paired with food (conditioning) in a specific order followed by the exposure to the CSs alone to measure the conditioned response (CR, conditioning test). For Experiment 1, the serial presentation of the five reinforced odors resulted in a higher CR for the initial and final odors in comparison with the middle ones. In Experiment 2, it was established that a 20-min trial is enough to produce appetitive conditioning in snail. For Experiment 3, the results of Experiment 1 were replicated while controlling for odor presentation order. Finally, in Experiment 4, the serial position effect was obtained when the interval between conditioning and test phases were minimized. The results observed in the present study provided evidence of the serial position effect in terrestrial snails. The theoretical implications of these are debated. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Telling that one object or moment is different from another one is fundamental to cognition and intelligent behavior. Most investigations examining same/different (S/D) concepts in animals have relied on testing static visual stimuli. To move beyond this limitation, we investigated how five pigeons learned and performed a motion S/D discrimination. Using a go/no-go task, dynamic motion fields built from dot elements were presented in sequence to display repeating (same) or changing (different) motions. Each trial consisted of 10 motion segments presented in succession using the direction and rate of dot movement in the motion field to exemplify the S/D relations. The pigeons learned this motion S/D discrimination. We further tested their performance by varying the number and persistence of the dots in the motion fields. The results indicated the pigeons likely extracted globally integrated perceptual summaries of the motions for comparison across the segments. Testing differing organizations of the S/D relations across segments indicated that this discrimination could be determined from as few as two segments and involved an updating comparison of at least four or more segments of the sequence during their presentation. Collectively, the experiments establish for the first time that pigeons can use motion features to classify sequential same and different experiences. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Research on approximate numerical estimation suggests that numerical representations can be influenced by nonnumerical magnitudes. Current theories of numerical cognition differ on the nature of this interaction. The present project evaluated the effect of task requirements on the stimulus control exerted by numerical and nonnumerical magnitudes on pigeons' numerical discrimination behavior. In a series of experiments, we explored the effects of cumulative area and item size on pigeons' numerical discrimination. The effect of cumulative area was assessed by presenting visual displays in which cumulative area and item number were either positively correlated, uncorrelated, or negatively correlated. The effect of item size was evaluated by presenting displays in which the size of individual items was varied across trials. Results confirmed that pigeons' numerical discrimination behavior accorded with Weber's law, a prime indicator of nonsymbolic numerical representation. The results further indicated that pigeons did not use numerical information when nonnumerical magnitudes also provided reliable information to solve the discrimination task. However, task manipulations that rendered the information provided by nonnumerical magnitudes unreliable successfully shifted stimulus control toward numerical magnitudes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

In a typical feature-positive discrimination, responding is reinforced (+) during the target stimulus (A) on trials with the feature stimulus (X), but not during target-alone trials (A-). When X and A are presented simultaneously, direct control by X is typically observed; however, when the stimuli are presented serially, X sets the occasion for responding to A. In the current dual-response procedures, one response (e.g., left lever press) was reinforced during feature-target trials (XA+) and a different response (e.g., right lever press) was reinforced during target-alone trials (A+). In Experiment 1, rats received either serial (X → A+) or simultaneous (X:A+) presentations of the feature-target compound along with target-alone trials (A+). Contrary to our predictions, the serial group failed to learn the discrimination and the simultaneous group demonstrated occasion setting. In Experiment 2, the salience of the feature was increased, which resulted in direct control by the feature in both groups. In Experiment 3, an additional serial group was included with a longer interval between the feature (X) and target (A). Despite the reduced temporal proximity of X to reinforcement, direct control was again observed in all groups. The current pattern of results in the simultaneous and serial groups is interpreted in relation to the enhanced salience of A relative to X, due to separate pairings of A-alone with reinforcement in the dual-response procedure. Consistent with previous findings, occasion setting was observed when A was most salient relative to X (Experiment 1, simultaneous group), but direct control was found when the salience of X was increased (Experiments 2-3). (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Previous experiments found that acceptance of saccharin by rats was reduced if they had prior experience of sucrose or some other highly palatable solution. This reduction in saccharin consumption was particularly extended after a switch from sucrose. On the surface, this seems to correspond to a successive negative contrast (SNC) effect. This term was coined by C. F. Flaherty to describe the situation where consumption of a target solution is reduced by prior experience of a more valuable solution, typically a more concentrated version of the target solution. However, SNC effects are normally transient and assessed relative to a nonshifted control. Here, we confirm that the reduction in consumption seen when shifting from sucrose to saccharin is persistent and is seen relative to the traditional unshifted control. In addition, an analysis of licking microstructure showed that the shift from sucrose to saccharin suppressed the hedonic value of saccharin relative to controls, but this effect was less persistent than consumption suppression. Interestingly, a similar dissociation is observed in extinction of conditioned taste aversion (CTA): suppression of consumption produced by CTA is far more persistent than suppression of hedonic value. The comparison of results across procedures suggests that persistent SNC produced by a qualitative downshift from sucrose to saccharin appears different from quantitative downshifts in the concentration of a single solution, and qualitative downshift effects may involve CTA. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Three experiments examined the impact of delayed outcomes on stimulus control of causal judgments using an interdimensional generalization procedure. Human participants rated the causal effectiveness of responses on multiple schedules, and then underwent a generalization test. In Experiment 1, a 3 s unsignaled outcome delay reduced ratings of causal effectiveness, relative to an immediate outcome, but had higher ratings compared to a component lacking outcomes. In a generalization test, incremental generalization gradients, indicating inhibitory control, were found for the stimulus associated with delayed outcomes when comparison was with immediate outcomes; but decremental gradients, indicating excitatory control, were found when the comparator lacked outcomes. In Experiment 2, signaled 3 s outcome delays produced higher causal ratings than unsignaled delays; with unsignaled delays producing incremental (inhibitory) and signaled delays producing decremental (excitatory), generalization gradients when compared against each other. In Experiment 3, relative to immediate outcomes, unsignaled delays produced incremental (inhibitory) gradients and signaled delays produced no gradient. These findings suggest similar factors may control judgments of causality as control conditioned responding. (PsycInfo Database Record (c) 2023 APA, all rights reserved).