Conditional Discrimination Learning Research Articles

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).

Frecuencia y tipos de retroalimentación sobre la precisión del responder en una tarea de discriminación condicional

Using a conditional discrimination task, the effects of content and frequency of feedback were assessed. Continuous and intermittent feedback was programmed for two groups of students; within groups specific and relational feedback was arranged for two sub. Accuracy was higher for the continuous-feedback group than for intermittent-feedback. We also found that the relational groups showed higher percentages of correct responses than specific feedback groups. Results are consistent with previous findings showing the relevance of the frequency and content of feedback on conditional discrimination learning. Findings are discussed based on their potential application to educational settings.

Hierarchical and configural control in conditional discrimination learning.

Considerable discussion has concerned the role of context in conditional discrimination learning. Some authors have proposed that contexts might operate hierarchically on CS-US associations, whereas others have proposed that the context plus the CS might be processed configurally. In the present article, we report the results of two experiments that assessed the role of context on pigeons' conditional discrimination learning. In Experiment 1, we found that our pigeons' responding was inconsistent with hierarchical processing; instead, they may have either relied on local features or on configural compounds comprising the context and the discriminative stimulus presented on each trial. In Experiment 2, we precluded the possibility of using local features by requiring the pigeons to attend to both of the compounds that were simultaneously presented on each trial to solve the task. Methodological and theoretical issues are discussed in light of this work. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Supplemental Material for Hierarchical and Configural Control in Conditional Discrimination Learning

Supplemental Material for Hierarchical and Configural Control in Conditional Discrimination Learning

Flexible conditional discrimination learning: Pigeons can learn to select the correct comparison stimulus, reject the incorrect comparison, or both.

In a simultaneous discrimination, pigeons are presumed to learn to about the correct stimulus, but they may also learn to avoid the incorrect stimulus. Similarly, in a conditional discrimination, they are presumed to learn about the relation between the sample stimulus and the correct comparison stimulus but not about the incorrect comparison stimulus. In the present research, we encouraged pigeons to learn about the incorrect comparison stimulus by increasing, over trials, the number of correct comparison stimuli with one sample, to compare with increasing the number of incorrect comparison stimuli over trials with the other sample. In Experiment 1, using colors and shapes, we found no difference in acquisition between the 2 sample types. However, when we replaced either the correct or incorrect comparison from training with a novel stimulus, the pigeons showed that they had learned to avoid the incorrect comparison when there were multiple correct comparisons and to select the single correct comparison when there were multiple incorrect comparisons. In Experiment 2, using national flags as stimuli, when tested with a novel flag stimulus, once again, the pigeons learned about the single correct comparison but not about the multiple incorrect comparisons. However, with the other sample, they appeared to learn about both the multiple correct comparisons and about the single incorrect comparison. This research indicates that pigeons can show considerable flexibility in what they learn in a conditional discrimination. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Conditional Learning Deficits in Children with ADHD can be Reduced Through Reward Optimization and Response-Specific Reinforcement

When children with ADHD are presented with behavioral choices, they struggle more than Typically Developing [TD] children to take into account contextual information necessary for making adaptive choices. The challenge presented by this type of behavioral decision making can be operationalized as a Conditional Discrimination Learning [CDL] task. We previously showed that CDL is impaired in children with ADHD. The present study explores whether this impairment can be remediated by increasing reward for correct responding or by reinforcing correct conditional choice behavior with situationally specific outcomes (Differential Outcomes). An arbitrary Delayed Matching-To-Sample [aDMTS] procedure was used, in which children had to learn to select the correct response given the sample stimulus presented (CDL). We compared children with ADHD (N = 45) and TD children (N = 49) on a baseline aDMTS task and sequentially adapted the aDMTS task so that correct choice behavior was rewarded with a more potent reinforcer (reward manipulation) or with sample-specific (and hence response-specific) reinforcers (Differential Outcomes manipulation). At baseline, children with ADHD performed significantly worse than TD children. Both manipulations (reward optimization and Differential Outcomes) improved performance in the ADHD group, resulting in a similar level of performance to the TD group. Increasing the reward value or the response-specificity of reinforcement enhances Conditional Discrimination Learning in children with ADHD. These behavioral techniques may be effective in promoting the learning of adaptive behavioral choices in children with ADHD.

Bearing fruit: Piloting a novel judgment bias task in an American black bear.

Judgment bias tasks can reveal changes in affect in animals as a function of environmental manipulations such as provision of enrichment. We assessed affect in an American black bear across seasonal changes in availability of a mulberry bush. We used a novel judgment bias task in which the background color of a touchscreen signaled whether the left or right positioned stimulus was correct. The bear learned the conditional rule in which the correct action for the white background (choose left) resulted in three pieces of food and the correct action for the black background (choose right) resulted in one piece of food. On probe trials involving intermediate gray backgrounds, left side responses indicated optimism and right side responses indicated pessimism. Tests took place at the beginning, middle, and end of mulberry season and again nearing the end of the summer and early fall before hibernation. The bear showed the most optimistic responses during the phase involving increased opportunities for foraging on mulberry. A follow-up experiment confirmed that the bear preferred three food items over one food item, suggesting the quantity-based discrimination was in fact salient to this bear. This is the first evidence for conditional discrimination learning in a black bear, validating the task to assess changes in affect.

Intraexperimental development of priming and event related potentials effects with abstract geometrical stimuli

In the current study we assessed the possibility of developing intraexperimentally behavioral priming and Event Related Potentials (ERP) effects that are often studied with stimuli to which participants typically have a very extensive pre-experimental history, like words. To do so we used abstract geometrical figures in a baseline Lexical Decision Task (LDT), followed by a conditional discrimination-training phase. We then repeated the LDT task to assess the effectiveness of training compared to baseline. We found that participants’ reaction time data in the post training LDT session changed, compared to the pre-training LDT session, according to the specific conditional discriminations taught in the training session. Similarly, neural results suggest the presence of an effect due to training that is absent in the baseline neural measures. Moreover, similar effects were also obtained using words. Results point to the possibility that conditional discrimination learning may be sufficient to establish effects that are often considered to be language specific.

Deficits in Conditional Discrimination Learning in Children with ADHD are Independent of Delay Aversion and Working Memory.

Adaptive behavior requires the adjustment of one’s behavioral repertoire to situational demands. The learning of situationally appropriate choice behavior can be operationalized as a task of Conditional Discrimination Learning (CDL). CDL requires the acquisition of hierarchical reinforcement relations, which may pose a particular challenge for children with Attention Deficit Hyperactivity Disorder (ADHD), particularly in light of documented deficits in short-term/working memory and delay aversion in ADHD. Using an arbitrary Delayed Matching-To-Sample task, we investigated whether children with ADHD (N = 46), relative to Typically Developing children (TD, N = 55), show a deficit in CDL under different choice delays (0, 8, and 16 s) and whether these differences are mediated by short-term/working memory capacity and/or delay aversion. Children with ADHD demonstrated poorer CDL than TD children under 8 and 16-second delays. Non-delayed CDL performance did not differ between groups. CDL differences were not mediated by short-term/working memory performance or delay aversion. Moreover, CDL performance under an 8-second delay was a better predictor of clinical status than short-term/working memory performance or delay aversion. CDL, under conditions of delay, is impaired in children with ADHD. This may lead to difficulties discriminating between different situational demands and adapting behavior according to the prevailing reward contingencies or expectations.

A Developmental Analysis of Children’s Equivalence-class Formation and Disruption

Developmental differences in children’s conditional discrimination learning, equivalenceclass formation, and equivalence-class disruption were investigated in two experiments. In Experiment 1, children between 2 and 9 years of age demonstrated age-related differences across a series of preliminary training steps, such that time to acquisition was more variable for younger than for older children on an initial identity matching and category matching task. However, uponcompletion of the preliminary training, there were no age-related differences in time to acquisition of the two arbitrary conditional discriminations that would serve as the basis for equivalence-class formation, nor were there differences in time to demonstrate stable equivalence classes (Experiment 2). Also in Experiment 2, children between 2 and 14 years of age were exposed to a potential challenge to the demonstrated equivalence classes; the reinforcement contingency for theAC conditional discrimination was reversed (i.e., given A1, A2 or A3, reinforcers were produced by selecting C2, C3, or C1 respectively). While there was little change in performance on reflexivity or BA symmetry tests following the challenge, age-related differences were obtained for CA symmetry and combined tests for equivalence. The older children were more likely to demonstrate an orderly change in equivalence-class membership consistent with the reversal training, while the younger children showed either little change or substantial disruption in their equivalence patterns. These data are considered in relation to more traditional investigations of children’s category formation, as well as their implications for the study of equivalence-class formation and flexibility.

Judgement bias in pigs is independent of performance in a spatial holeboard task and conditional discrimination learning

Biases in judgement of ambiguous stimuli, as measured in a judgement bias task, have been proposed as a measure of the valence of affective states in animals. We recently suggested a list of criteria for behavioural tests of emotion, one of them stating that responses on the task used to assess emotionality should not be confounded by, among others, differences in learning capacity, i.e. must not simply reflect the cognitive capacity of an animal. We performed three independent studies in which pigs acquired a spatial holeboard task, a free choice maze which simultaneously assesses working memory and reference memory. Next, pigs learned a conditional discrimination between auditory stimuli predicting a large or small reward, a prerequisite for assessment of judgement bias. Once pigs had acquired the conditional discrimination task, optimistic responses to previously unheard ambiguous stimuli were measured in the judgement bias task as choices indicating expectation of the large reward. We found that optimism in the judgement bias task was independent of all three measures of learning and memory indicating that the performance is not dependent on the pig’s cognitive abilities. These results support the use of biases in judgement as proxy indicators of emotional valence in animals.

Brodmann Areas 8 and 9 Including the Frontal Eye Field

Based on cytoarchitectonic analyses, Brodmann assigned numbers 8 and 9 to certain areas of the dorsal and medial prefrontal cortex (PFC) in humans and monkeys. Petrides and Pandya re-analyzed the cytoarchitectures of the human and monkey PFCs, and proposed slightly different brain maps for both species. They assigned numbers 8, 9 and 9/46 to the areas that were originally named areas 8 and 9. Areas 8 and 9 have both lateral and medial regions respectively. The lateral area 8 is important for conditional discrimination learning. The frontal eye field which occupies the most caudal region of area 8, is responsible for visual attention and control of eye movements. The lateral area 9 and area 9/46 are functionally similar to area 46 and play important roles in executive control. The dorsomedial prefrontal cortex (DMPFC) comprises the medial regions of areas 8 and 9 and is related to "Theory of Mind" and social cognition. The DMPFC is also known to show "default mode of brain activity" (i.e., more activity during rest than during cognitive task).

Superior ambiguous occasion setting with visual than temporal feature stimuli.

Three experiments with rats compared the relative ease with which different sets of visual or temporal cues could participate in Pavlovian learning. In Experiment 1, 1 group was trained to discriminate between visual cues (Light vs. Dark), whereas the other group learned to discriminate between temporal cues (early [10 s] vs. late [90 s]). Both groups learned to distinguish food-paired from nonpaired periods equally well. In Experiment 2, 2 groups were trained on an ambiguous occasion setting task. For Group Visual, a 2-min Light period signaled that 1 10-s auditory conditioned stimulus, CS1, was reinforced with 1 unconditioned stimulus, US1, but that CS2 was not reinforced; whereas a 2-min dark period signaled that CS1 was not reinforced, but CS2 was reinforced with US2 (i.e., Light: CS1-US1, CS2-; Dark: CS1-, CS2-US2). For Group Temporal, early (10-s) or late (90-s) temporal cues within each of these Light and Dark periods were diagnostic of these contingencies (i.e., Early: CS1-US1, CS2-; Late: CS1-, CS2-US2). Group Visual learned the task, but Group Temporal did not. In Experiment 3 we demonstrated that animals could not solve a related temporal ambiguous occasion setting task in which 1 visual stimulus signaled that both CSs were reinforced early whereas the other visual stimulus signaled that the CSs were reinforced only late. Contrary to a currently popular information theory approach to timing in Pavlovian learning, these results suggest that overt nontemporal visual stimuli are better incorporated into conditional discrimination learning than are temporal stimuli. (PsycINFO Database Record

El efecto de consecuencias diferenciales: un caso de investigación traslacional

La investigación traslacional representa un esfuerzo por integrar los hallazgos derivados de la investigación básica y aproximarlos al ámbito aplicado. El presente trabajo plantea al área de investigación relativa al Efecto de Consecuencias Diferenciales (ECD) como un caso de investigación traslacional caracterizada por su contribución en el aprendizaje de discriminaciones condicionales. Se realiza una revisión que parte de algunos de los trabajos germinales con animales de laboratorio y que continúa con los primeros estudios con humanos. Posteriormente, se revisan algunos estudios que destacan el potencial de aplicación de los Procedimientos con Consecuencias Diferenciales (PCD) como herramienta para el tratamiento de personas con diversos padecimientos asociados a deficiencias en el aprendizaje y la memoria, así como su empleo en el ámbito educativo en situaciones que implican el aprendizaje de discriminaciones condicionales.

Mejora del aprendizaje discriminativo en niños: consecuencias diferenciales y administración manual de diferentes formas de refuerzo

In recent years, several studies have demonstrated that discriminative learning is facilitated when each association to be learned is always followed by a unique outcome. This way of providing outcomes was called the differential outcomes procedure (DOP). The aim of the study reported here was to assess whether the DOP could improve learning of symbolic conditional discriminations in 5- and 7-year-old children when performing a paper-and-pencil task using different types of training in which: 1) reinforcers were given after correct choices (+), 2) reinforcers were withdrawn when errors were made (-), or 3) a combination of both (+/-). In Experiments 1a and 1b secondary reinforcers were used along with primary reinforcers, while in Experiments 2a and 2b only primary reinforcers were used. Participants showed better performance when differential outcomes were arranged regardless of the type of reinforcers (secondary plus primary or only primary) and the different strategies of reinforcement (+, -, or +/-). These results add to those found by Martínez et al. (2009, 2013) and demonstrate that the beneficial effect of the DOP on discriminative learning is also independent of the way in which the stimuli and the outcomes are presented, facilitating its use in applied contexts.

Explorando el potencial de aprendizaje de personas con esquizofrenia en distintas condiciones psicopatológicas

The aim of this paper is to explore empirically the learning potential of people with schizophrenia in opposite conditions of psychopathological stability. For this purpose, a general procedure of conditional discrimination learning was introduced by conducting a study on the formation of equivalence classes. The sample consisted of 8 inpatient adults included in the program of Severe Mental Disorders, aged between 20 and 53 years. Because of dropouts, the initial procedure was modified in order to reduce the duration and attentional effort of the task. The results showed that people with schizophrenia can acquire stimulus equivalence with standard procedure both in terms of stability and psychopathological decompensation, in the presence of strong positive symptoms. This finding is relevant both for therapy, conceived in terms of learning, and for designing programs in the context of rehabilitation and recovery in schizophrenia.

O uso do Procedimento Blocado no Ensino de Discriminações Condicionais de Identidade para em Pessoas com Autismo: Efeitos do emprego de Três Estímulos Modelo

O procedimento blocado é um dos procedimentos eficazes para o ensino de escolha de acordo com o modelo. O procedimento tipicamente emprega dois estímulos de comparação e alterna dois estímulos modelo em blocos com um determinado número de tentativas consecutivas, que é reduzido até que os modelos são apresentados aleatoriamente. Entretanto, o procedimento é considerado ineficiente por requerer um número grande de tentativas e ensinar apenas duas relações. O presente estudo investigou os efeitos do aumento de dois para três estímulos modelo na aprendizagem de relações de identidade em pessoas com autismo. Participaram do estudo cinco indivíduos com autismo. Cada sessão tinha 24 tentativas; os passos iniciais apresentavam um mesmo estímulo modelo em uma sessão. À medida que o participante respondia com precisão, os três estímulos modelo eram apresentados em números de tentativas consecutivas cada vez menores na sessão: de 24 para 8, de 8 para 4, de 4 para 2; e em sequência aleatória. Depois de aprendidas novas relações de identidade, os participantes eram submetidos a um teste de generalização. Todos os participantes aprenderam relações de identidade com pelo menos dois conjuntos de estímulos, embora procedimentos remediativos tenham sido necessários para alguns participantes. Quatro de cinco participantes demonstraram generalização do responder. O procedimento blocado funcionou para o ensino simultâneo de três relações condicionais, o que é importante para eficiência de ensino e evitar o estabelecimento de topografias de controle de estímulos irrelevantes. A discussão aborda questões acerca dos procedimentos e da programação de ensino de relações condicionais e identidade generalizada para indivíduos com atraso no desenvolvimento. Palavras-chave: procedimento blocado; discriminação condicional de identidade; identidade generalizada; autismo

Sleep enhances inhibitory behavioral control in discrimination learning in rats.

Sleep supports the consolidation of memory, and it has been proposed that this enhancing effect of sleep pertains in particular to memories which are encoded under control of prefrontal–hippocampal circuitry into an episodic memory system. Furthermore, repeated reactivation and transformation of such memories during sleep are thought to promote the de-contextualization of these memories. Here, we aimed to establish a behavioral model for the study of such sleep-dependent system consolidation in rats, using a go/nogo conditional discrimination learning task known to essentially depend on prefrontal–hippocampal function. Different groups of rats were trained to criterion on this task and, then, subjected to 80-min retention intervals filled with spontaneous morning sleep, sleep deprivation, or spontaneous evening wakefulness. In a subsequent test phase, the speed of relearning of the discrimination task was examined as indicator of memory, whereby rats were either tested in the same context as during training or in a different context. Sleep promoted relearning of the conditional discrimination task, and this effect was similar for testing memory in the same or different context (p < 0.001). Independent of sleep and wakefulness during the retention interval, animals showed faster relearning when tested in the same context as during learning, compared with testing in a different context (p < 0.001). The benefitting effect of sleep on discrimination learning was primarily due to an enhancing effect on response suppression during the nogo stimulus. We infer from these results that sleep enhances memory for inhibitory behavioral control in a generalized context-independent manner and thereby might eventually also contribute to the abstraction of schema-like representations.

Rapid generation of balanced trial distributions for discrimination learning procedures: A technical note

We describe novel computer algorithms for rapid, sometimes virtually instantaneous generation of trial sequences needed to instrument many behavioral research procedures. Implemented on typical desktop or laptop computers, the algorithms impose constraints to forestall development of undesired stimulus control by position, recent trial outcomes, and other variables that could impede simple and conditional discrimination learning. They yield trial-by-trial lists of sequences that can serve (1) as inputs to procedure control software or (2) in generating templates for constructing sessions for implementation by hand or machine.

Successive and conditional discrimination learning in pigs

We studied the ability of pigs to discriminate tone cues using successive and conditional discrimination tasks. Pigs (n = 8) were trained in a successive discrimination Go/No-Go task (Experiment 1) to associate a Go-cue with a reward at the end of a runway and a No-Go-cue with the absence of reward. Latency to reach the goal-box was recorded for each cue-type. Learning of a conditional discrimination task was compared between low-birthweight (LBW, n = 5) and normal-birthweight (NBW, n = 6) pigs (Experiment 2) and between conventional farm (n = 7) and Göttingen miniature (n = 8) pigs (Experiment 3). In this active-choice task, one cue signalled a response in a right goal-box was correct and a second cue signalled a response in a left goal-box was correct. Cues were differentially rewarded. The number of sessions to learn the discrimination and number of correct choices per cue-type were recorded. In Experiment 1, four out of eight pigs showed learning on the task, that is, a higher latency to respond to the No-Go-cue, within 25 sessions. In Experiment 2, eight out of 11 pigs learned the discrimination within 46 sessions. LBW learners learned faster than NBW learners. In Experiment 3, all 15 pigs learned the task within 16 sessions. Göttingen miniature pigs learned faster than conventional farm pigs. While some methodological issues may improve the Go/No-Go design, it is suggested that an active-choice task yields clearer and more consistent results than one relying on latency alone.