The role of similarity in human associative learning.

In 2 experiments, humans received sequences of patterns that were similar (AX→BX, AY→BY, AZ→BZ) or dissimilar (CX→DY, CY→DZ, CZ→DX). The patterns were portrayed as bugs that could be eliminated with 2 insecticide sprays (red or blue). Either spray eliminated bugs with Features A and C, and participants learned by trial and error to use one spray (e.g., red) to eliminate bugs with Feature B and the other spray (e.g., blue) to eliminate those with Feature D. In Experiment 1, participants' spray choice for bugs with Feature A came to match that used to eliminate bugs with Feature B, but there was no such associative transfer between Features C and D. That is, similarity promoted associative transfer of responding between paired patterns when the features used to manipulate similarity (i.e., X, Y, and Z) were irrelevant. In Experiment 2, in which X, Y, and Z were relevant to the solution of configural discrimination, similarity hindered such associative transfer. These results complement those found in pigeons (R. A. Rescorla & D. J. Gillan, 1980) and indicate that similarity should not be accorded independent status as a principle of associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Configural processes in human associative learning.

The extent to which human discrimination learning is based on elemental or configural stimulus representations was examined in 7 experiments. In Experiments 1a and 1b, participants were able to learn nonlinear discrimination problems in a food-allergy task. In unique-cue theories, such learning is explained by individual stimulus elements acquiring independent connections with the outcome and also combining to form unique cues that function elementally. In Stage 1 of Experiments 2, 3, and 4a–c, Food A signaled an allergy outcome (O) (A?→?O) when presented alone but signaled no allergy (AB?→?no O) when paired with Food B. In Stage 2, Food B was paired with the allergy (B?→?0). In a test phase, the original discrimination between A and AB was found to be intact, at variance with the unique-cue theory. By contrast, in Experiments 5a, 5b, and 6, an effect of the B?→?O trials on the A–AB discrimination was observed with training procedures previously found by D. A. Williams (1995) to encourage elemental processing. Experiment 7 showed that the influence of B?→?0 trials on the A–AB discrimination was unaffected by pretreatments designed to foster an elemental processing strategy.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feature- and rule-based generalization in human associative learning.

Two experiments examined the contributions of feature- and rule-based knowledge in a human associative learning task. Participants were presented with concurrent negative (A?→?O, B?→?O, AB?→?no O) and positive (C?→?no O, D?→?no O, CD?→?O) patterning problems in which certain combinations of foods were associated with an allergy outcome (O). In the test stage, some participants showed normal feature-based generalization to novel trial types, whereas other participants transferred the patterning rule (i.e., a compound and its elements signal opposite outcomes). Mastery of the discrimination presented in the training phase was strongly linked to rule-based generalization. The results suggest that models of human associative learning need to incorporate mechanisms for rule-based as well as for feature-based generalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resistance to interference in human associative learning: evidence of configural processing

This article provides a conceptual and practical framework called the Ecology of Outcomes. Based on this framework, agencies that serve children and families build and use outcome-oriented information systems to respond to their clients in a more flexible manner. The goal is to improve promising programs by involving stakeholders in outcome identification and in utilization of results. Problems addressed include the emphasis human services place on rules compliance, lack of feedback to program staff to allow for midcourse correction, and lack of input by key stakeholders in the identification of outcomes to be measured. The following components of the framework are described: principles of outcome accountability, prerequisites and building blocks, implementing an outcome information system, and utilizing the results. Key elements of the framework are the integration of outcome information into a service system's decision-making process and the inclusion of client, stakeholder, and provider satisfaction information.     

Selective attention in human associative learning and recognition memory.

Four experiments examined the role of selective attention in a new causal judgment task that allowed measurement of both causal strength and cue recognition. In Experiments 1 and 2, blocking was observed; pretraining with 1 cue (A) resulted in reduced learning about a 2nd cue (B) when those 2 cues were trained in compound (AB+). Participants also demonstrated decreased recognition performance for the causally redundant Cue B, suggesting that less attention had been paid to it in training. This is consistent with the idea that attention is preferentially allocated toward the more predictive Cue A, and away from the less predictive Cue B (e.g., N. J. Mackintosh, 1975). Contrary to this hypothesis, in Experiments 3 and 4, participants demonstrated poorer recognition for the most predictive cues, relative to control cues. A new model, which is based on N. J. Mackintosh's (1975) model, is proposed to account for the observed relationship between the extent to which each cue is attended to, learned about, and later recognized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquired equivalence and distinctiveness in human discrimination learning: Evidence for associative mediation.

In the first stage of Experiments 1-3, subjects learned to associate different geometrical figures with colors or with verbal labels. Performance in Stage 2, in which the figures signaled which of 2 motor responses should be performed, was superior in subjects required to make the same response to figures that had shared the same Stage 1 associate. A third stage of testing showed that the events used as associates in Stage 1 were capable of evoking the motor response trained in Stage 2, an outcome predicted by an associative interpretation of such transfer effects. Experiment 4 provided evidence that the relevant associations can be effective in controlling motor responding even when subjects report an antagonistic relationship between the events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is tube-escape learning by protozoa associative learning?

The ciliate protozoa, Stentor and Paramecium, have been reported to escape from the bottom end of narrow capillary tubes into a larger volume of medium with increasing rapidity over the course of trials. This change in behavior has been considered an apparent example of associative learning. This decrease in escape time is not due to a change in the protozoa's environment, their swimming speed, frequency of ciliary reversals, or the proportion of time spent forward or backward swimming. Instead, most of the decrease results from a decrease in the proportion of time spent in upward swimming. However, a similar decrease in upward swimming occurs when the task is altered to require escape from the upper end of the capillary tubes. Because the protozoa exhibit the same change in behavior regardless of the locus of the reinforcing stimulus, tube-escape learning is not associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Operant escape learning in decerebrate duck embryos.

Trained 192 Peking duck embryos (Anas platythynchos) in an operant escape task on Day 25 of incubation (total incubation period of 27 days) following decerebration on Day 24. Experimental embryos successfully acquired the operant response, which involved the performance of a discrete foot flexion to terminate a shock applied to the wing. The decerebrate embryos resembled normal unoperated embryos of this age in their acquisition of the operant behavior. Results demonstrate that this form of learning can be acquired without benefit of telencephalic structures, at least at this point in development. Differences in the consequences of decerebration during prenatal or neonatal vs adult stages are discussed. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of an amygdalo-nigrostriatal pathway in associative learning

The present study examined the role of an amygdalo-nigrostriatal pathway in associative learning. An asymmetrical lesion model was used to test whether a circuit from the amygdala central nucleus to the dorsolateral striatum, via the substantia nigra, is critical for mediating conditioned orienting responses. Rats with an asymmetrical lesion, consisting of neurotoxic removal of central nucleus neurons in one hemisphere and depletion of the dopamine innervation of the dorsolateral striatum in the contralateral hemisphere, failed to acquire conditioned orienting responses. In contrast, the asymmetrical lesion had no effect on spontaneous orienting or learning another response directed to the source of the food unconditioned stimulus in the same task. A second experiment tested the effect of reversible inactivation of the dorsolateral striatum contralateral to a neurotoxic central nucleus lesion on acquisition of the conditioned orienting response. Although inactivation did not affect spontaneous orienting, rats failed to acquire the conditioned orienting response during sessions in which inactivation occurred. Immediately after the inactivation procedure was terminated, however, a significant increase in orienting to the conditioned stimulus was evident. These data support the interpretation that the dorsolateral striatum provides a route for the expression of the conditioned orienting response but is not essential for acquisition of this learned behavior.     

Brain indices of nonconscious associative learning

Using a classical conditioning technique, this study investigated whether nonconscious associative learning could be indexed by event-related brain activity (ERP). There were three phases. In a preconditioning baseline phase, pleasant and unpleasant facial schematics were presented in awareness (suprathreshold). A conditioning phase followed, in which stimuli were presented outside awareness (subthreshold, via energy masking), with an unpleasant face (CS+) linked to an aversive shock and a pleasant face (CS-) not linked to a shock. The third, postconditioning phase, involved stimulus presentations in awareness (suprathreshold). Evidence for acquisition of a conditional response was sought by comparing suprathreshold pre- and postconditioning phases, as well as in the subthreshold conditioning phase itself. For the pre-postconditioning phase analyses, significant ERP component differences differentiating CS+ and CS- were observed for N1, P2, and especially P3. For the conditioning phase, significant differences were observed in the 100-400 ms. post-stimulus region reflecting a CS+ processing negativity. Brain activity does indeed index the acquisition of a conditional response to subthreshold stimuli. Associative learning can occur outside awareness.     

Comparing elemental and configural associative theories in human causal learning: A case for attention.

In two causal learning experiments with human participants, the authors compared various associative theories that assumed either elemental (unique cue, modified unique cue, replaced elements model, and Harris' model) or configural processing of stimuli (Pearce's theory and a modification of it). The authors used modified patterning problems initially suggested by Redhead and Pearce (1995). Predictions for all theories were generated by computer simulations. Both configural theories and the unique cue approach failed to account for the observations. The replaced elements model was able to account for part of the data, but only if the replacement parameters could vary across discrimination problems. The Harris model and the modified unique cue approach, assuming that the salience of stimuli decreases with an increasing number of stimuli in a compound, successfully accounted for all of our data. This success implies that attentional factors should be explicitly taken into account in associative learning theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imagery and learning: Item recognition and associative recall.

Two experiments compared the effects of neutral, separate, and interactive imagery instructions on the learning performance of 160 1st and 168 5th graders for both single-item and paired-associate tasks. As in previous studies, instructions to use interactive imagery were facilitative only for the older Ss. However, further investigation revealed that both younger and older Ss who reported using images did show facilitation, compared with those who did not report using images. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nicotine enhances context learning but not context-shock associative learning.

Nicotine has been found to enhance learning in a variety of tasks, including contextual fear conditioning. During contextual fear conditioning animals have to learn the context and associate the context with an unconditioned stimulus (footshock). As both of these types of learning co-occur during fear conditioning, it is not clear whether nicotine enhances one or both of these types of learning. To tease these two forms of learning apart, the authors made use of the context preexposure facilitation effect (CPFE). Acquisition of the CPFE requires that contextual and context-shock learning occurs on separate days, allowing for their individual manipulation. Nicotine (0.09 mg/kg) administered prior to contextual learning and retrieval enhanced the CPFE whereas administration prior to context-shock learning and retrieval had no effect. Thus, nicotine enhances contextual learning but not context-shock associative learning. Finally, the results are discussed in terms of a theory of how nicotine could alter hippocampal-cortical-amygdala interactions to facilitate contextual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some phenomena of associative learning in honeybees.

Two experiments present data on extinction in 111 free-flying honeybees previously reinforced for landing on distinctively colored and scented targets. A variety of phenomena familiar from the study of vertebrate learning, such as the overlearning-extinction effect, the partial reinforcement effect, overshadowing, summation, and conditioned inhibition, are described, and their significance is considered. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conflict adaptation by means of associative learning.

Cognitive control is responsible for adapting information processing in order to carry out tasks more efficiently. Contrasting global versus local control accounts, it has recently been proposed that control operates in an associative fashion, that is, by binding stimulus–response associations after detection of conflict (Verguts & Notebaert, 2009). Here, this prediction is explicitly tested for the first time. In a task-switching study where both tasks use the same relevant information, we previously reported conflict adaptation over tasks (Notebaert & Verguts, 2008). In the current experiment, we demonstrate that this is restricted to conditions where both tasks use the same effectors, thereby supporting the associative control account. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Negative priming in associative learning: Evidence from a serial-habituation procedure.

Rats received exposure to two serial compounds (A-X and B-Y) comprising auditory stimuli (A and B) followed by localized visual stimuli (X and Y). A and B came to elicit responses that reflected the location of X and Y (Experiment 1). The orienting response (OR) elicited by X and Y declined during exposure to the A-X and B-Y compounds and was restored on trials when A preceded Y, and B preceded X (Experiments 2 and 3). These results, observed with use of relatively neutral stimuli, parallel those observed during Pavlovian conditioning and provide support for A. R. Wagner's ( 1981) account of associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative priming in associative learning: Evidence from a serial-conditioning procedure.

Three experiments investigated the suggestion that a predicted or primed stimulus commands less processing and consequently elicits a weaker CR than a stimulus that is not primed. In each experiment rats received initial training in which the presentation of each of 2 serial compounds, A-X and B-Y, was followed by the delivery of food. Subsequently, X's capacity to elicit the CR, approaching the site of food delivery, was assessed when X was preceded by Stimulus A (i.e., primed) or was presented after Stimulus B. Stimulus X elicited a more vigorous response when it was presented after B than when it followed A. These results show that the ability of one event to elicit its CR is reduced if its presentation has been predicted by some other event. This negative priming effect supports one aspect of A. R. Wagner's (1981) model of Pavlovian conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An associative model of geometry learning: A modified choice rule.

In a recent article, the authors (Miller & Shettleworth, 2007; see record 2007-09968-001) showed how the apparently exceptional features of behavior in geometry learning ("reorientation") experiments can be modeled by assuming that geometric and other features at given locations in an arena are learned competitively as in the Rescorla-Wagner model and that the probability of visiting a location is proportional to the total associative strength of cues at that location relative to that of all relevant locations. Reinforced or unreinforced visits to locations drive changes in associative strengths. Dawson, Kelly, Spetch, and Dupuis (2008; see record 2008-09669-009) have correctly pointed out that at parameter values outside the ranges the authors used to simulate a body of real experiments, our equation for choice probabilities can give impossible and/or wildly fluctuating results. Here, the authors show that a simple modification of the choice rule eliminates this problem while retaining the transparent way in which the model relates spatial choice to competitive associative learning of cue values. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute inactivation of the inferior olive blocks associative learning

Can acute inactivation of the inferior olive block associative learning? We anaesthetized the inferior olive with lidocaine while rabbits simultaneously: (i) performed conditioned nictitating membrane responses to a flashing light to which they had already been trained; and (ii) underwent their first experience with classical conditioning of the same response to a tone. Inactivation of the inferior olive immediately and reversibly abolished the performance of conditioned responses and prevented learning during rabbits' initial conditioning with a tone-conditioned stimulus. When olivary function was restored, rabbits showed no signs of having learned under olivary anaesthesia. The experiment demonstrates that an acute disruption in olivary function can block learning, in addition to severely degrading motor control. The results are interpreted to indicate the importance of the inferior olive in optimizing learning, perhaps through a general role in regulating temporal processing.     

Aging and monitoring associative learning: Is monitoring accuracy spared or impaired?

Mixed lists of associatively related and unrelated paired associates were used to study monitoring of associative learning. Older and younger adults produced above-chance levels of relative accuracy, as measured by intraindividual correlations (γ) of judgments of learning (JOLs) with item recall. JOLs were strongly influenced by relatedness, and this effect was greater for older adults. Relative accuracy was higher for unrelated than for related pairs. Correlations of JOLs with item recall for a randomly yoked learner indicated that access to one's own encoding experiences increased relative accuracy. Both age groups manifested a contrast effect (lower JOLs for unrelated items when mixed with related items). Aging appears to spare monitoring of encoding, even though it adversely affects associative learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)