Journal of Experimental Psychology-Animal Learning and Cognition最新文献

The Pavlovian-instrumental transfer (PIT) paradigm is widely used to assay the motivational influence of reward-predictive cues, reflected by their ability to invigorate instrumental behavior. Leading theories assume that a cue's motivational properties are tied to predicted reward value. We outline an alternative view that recognizes that reward-predictive cues may suppress rather than motivate instrumental behavior under certain conditions, an effect termed positive conditioned suppression. We posit that cues signaling imminent reward delivery tend to inhibit instrumental behavior, which is exploratory by nature, in order to facilitate efficient retrieval of the expected reward. According to this view, the motivation to engage in instrumental behavior during a cue should be inversely related to the value of the predicted reward, since there is more to lose by failing to secure a high-value reward than a low-value reward. We tested this hypothesis in rats using a PIT protocol known to induce positive conditioned suppression. In Experiment 1, cues signaling different reward magnitudes elicited distinct response patterns. Whereas the one-pellet cue increased instrumental behavior, cues signaling three or nine pellets suppressed instrumental behavior and elicited high levels of food-port activity. Experiment 2 found that reward-predictive cues suppressed instrumental behavior and increased food-port activity in a flexible manner that was disrupted by post-training reward devaluation. Further analyses suggest that these findings were not driven by overt competition between the instrumental and food-port responses. We discuss how the PIT task may provide a useful tool for studying cognitive control over cue-motivated behavior in rodents. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Three experiments examined the preference for pattern versus random sequences. In all experiments the elements composing the sequences were visual images presented sequentially on a touchscreen. Reinforcement was randomly programmed on .16 of the element presentations for each type of trial. For pattern sequences the elements occurred in the same order and at the same location on each presentation of the sequence. For random sequences the elements could occur in any order on a given trial. The experiments were conducted in two phases. In the first phase, termed forced-choice, subjects, male Silver Kings, were given either a pattern sequence or a random sequence to work on in a given trial. Subjects received this first phase until performance on each type of sequence was equated. In the second phase, termed free-choice, subjects could choose which of the two sequences to work on in each trial. Results indicated that although performance was equated between the two types of sequences in the forced-choice phase, when given the choice subjects selected the pattern sequence on 70 percent of the trials. This finding held in Experiments 1 and 2 although there were procedural differences between these two experiments. In Experiment 3 the reinforcement probability for random sequences was increased to be 50 percent higher than for pattern sequence. In this arrangement subjects chose random sequences on nearly 83 percent of the free-choice trials, indicating that the preference for pattern sequences was not intractable. Results suggest that the preference for pattern sequences that was observed when reinforcement was equated between the two types of sequences may have been the result of the added information concerning forthcoming element presentations that was available from pattern sequences. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The field of associative learning theory was forever changed by the contributions of Robert A. Rescorla. He created an organizational structure that gave us a framework for thinking about the key questions surrounding learning theory: what are the conditions that produce learning?, what is the content of that learning?, and how is that learning expressed in performance? He gave us beautifully sophisticated experimental designs that tackled deep theoretical problems in experimentally clever and elegant ways. And he left us with a collection of work that fundamentally altered the way we as a field think about basic learning processes. Few scientists have impacted their field in the way that Rescorla impacted animal learning theory. In this paper, we introduce this special issue (Developments in Associative Theory: A Tribute to Robert A. Rescorla) by considering some of the many ways in which Rescorla's empirical and theoretical contributions impacted learning theory over his almost 50-year career. We conclude by identifying multiple fundamental issues we think he would have found especially fruitful to pursue as we continue to move forward. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

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).

Conditioned responding is sensitive to reinforcement rate. This rate-sensitivity is impaired in genetically modified mice that lack the GluA1 subunit of the AMPA receptor. A time-dependent application of the Rescorla-Wagner learning rule can be used to derive an account of rate-sensitivity by reflecting the balance of excitatory and inhibitory associative strength over time. By applying this analysis, the impairment in GluA1 knockout mice may be explained by reduced sensitivity to negative prediction error and thus, impaired inhibitory learning, such that excitatory associative strength is not reduced during the nonreinforced periods of a conditioned stimulus. The article describes a test of the role of GluA1 in inhibitory learning that requires summing of the associative strengths of cues presented in compound. Mice were trained on a feature negative discrimination of the form A+/AX-. GluA1 knockout mice acquired the discrimination to a similar extent as controls. The inhibitory properties of cue X were verified in a summation test that included a control for nonassociative, external inhibition. The performance of GluA1 knockout mice was similar to that of controls. However, in line with previous findings, GluA1 deletion impaired the precision of timing of conditioned responding. These results provide further evidence that impaired sensitivity to reinforcement rate is not a consequence of impaired inhibitory learning. The results may more readily fit with accounts of rate sensitivity that propose that it reflects encoding of temporal and numeric information rather than being a consequence of changes in associative strength over time. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Negative patterning tasks are a key tool to unveil the mechanisms by which stimulus representations are acquired-a central concern in Robert Rescorla's research. In these tasks, target stimuli are reinforced when presented individually (A+/B+) but not when presented in compound (AB-). The discrimination of single stimuli from their compound presentation is a challenge for theories of associative learning, because it cannot be explained by the simple accrual of associative strength. The present study examined the conditions under which mice learn this part-whole discrimination in olfactory stimuli using a novel instrumental methodology. In two experiments, reinforcement was contingent on distinct responses depending on whether a set of odor mixtures were presented in isolation or as a compound. Using C57BL/6 mice, Experiment 1 showed a mutual interference between learning a response to individual odors and learning a different response to those odors presented in compound. Using wild-type APP/PS1 mice (a control strain for a murine model of Alzheimer's disease), Experiment 2 replicated this interference and showed that it is stimulus-specific. These experiments show that the instrumental patterning task may not only complement Pavlovian negative patterning tasks but may also motivate its own questions on the representation of complex stimuli. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The associative learning theory of Robert Rescorla and Allan Wagner has been duly celebrated for its 50-year reign as the predominant model in learning science. One special recognition is warranted: its close correspondence with David Hume's associative theory of causality judgment. Hume's rules by which causes come to suggest effects are not only embraced by the Rescorla-Wagner model, but their mechanistic account makes precise quantitative predictions that can be assessed by empirical evidence rather than by speculation and argumentation. Framed in this way, the Rescorla-Wagner model truly represents the scientific culmination of Hume's philosophical theory of causation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

In 1988 Robert Rescorla published an article in the Annual Review of Neuroscience that addressed the circumstances under which learning occurs, some key methodological issues, and what constitutes an example of learning. The article has inspired a generation of neuroscientists, opening the door to a wider range of learning phenomena. After reviewing the historical context for his article, its key points are briefly reviewed. The perspective outlined enabled the study of learning in simpler preparations, such as the spinal cord. The period after 1988 revealed that pain (nociceptive) stimuli can induce a lasting sensitization of spinal cord circuits, laying down a kind of memory mediated by signal pathways analogous to those implicated in brain dependent learning and memory. Evidence suggests that the spinal cord is sensitive to instrumental response-outcome (R-O) relations, that learning can induce a peripheral modification (muscle memory) that helps maintain the learned response, and that learning can promote adaptive plasticity (a form of metaplasticity). Conversely, exposure to uncontrollable stimulation disables the capacity to learn. Spinal cord neurons can also abstract that stimuli occur in a regular (predictable) manner, a capacity that appears linked to a neural oscillator (central pattern generator). Disrupting communication with the brain has been shown to transform how GABA affects neuronal function (an example of ionic plasticity), releasing a brake that enables plasticity. We conclude by presenting a framework for understanding these findings and the implications for the broader study of learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Six experiments with rats examined the nature of inhibition learned in an operant feature-negative (FN) discrimination. The results of prior experiments that examined instrumental extinction rather than FN learning suggest that inhibition can be very specific to the inhibited response. In Experiment 1, we trained lever-press and chain-pull responses in separate but parallel FN discriminations (AR1+, ABR1-, CR2+, and CDR2-) and then tested both inhibitors (B and D) with both responses. Of primary interest was the extent to which the inhibitors suppressed the response they were trained with (same-response inhibition) versus the other response (cross-response inhibition). We found that cross-response inhibition was robust and essentially equal to same-response inhibition. Experiment 2 replicated this result and confirmed stronger inhibition after FN learning than after a differential inhibition procedure (AR1+, BR1-, CR2+, and DR2-). There was also little evidence that cross-response inhibition was due to a demonstrable competing response. Experiment 3 found that cross-response inhibition did not depend on having the two responses reinforced by a common outcome. Experiments 4 and 5 then found that cross-response inhibition depended substantially (though not completely) on the transfer target response having been trained in its own FN discrimination. However, Experiment 6 found that inhibition after instrumental extinction (as opposed to FN learning) was still highly response-specific when the transferred-to response had been trained in an FN discrimination. The overall results suggest that the characteristics of inhibition in instrumental extinction and FN learning differ and that transfer of FN inhibition across responses depends at least partly on previous "inhibitability" of the target response. (PsycInfo Database Record (c) 2022 APA, all rights reserved).