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

Intermixed exposure to two similar stimuli, for example, AX and BX, improves subsequent discrimination between them compared to blocked exposure (the intermixed/blocked effect). Salience modulation models, developed mainly from research with nonhuman animals and exposure to widely spaced similar stimuli, explain this effect in terms of increased salience of the unique elements, A and B. Conversely, the results from experiments initially conducted with humans and exposure to close spaced similar stimuli have led to the suggestion that it is the development of well-unitized representations of unique elements that leads to better discrimination, leaving the unique elements with less effective salience. The experiments carried out here aim to replicate the intermixed/blocked effect in rats using an exposure procedure with rapid succession between stimuli and to assess the effective salience of unique elements. In Experiment 1, an aversion to a new flavor, Y, was conditioned and then an external inhibition test with AY was given. In Experiment 2, an aversion to A was conditioned and its extinction was measured on unreinforced trials. In Experiment 3, an aversion to AY was conditioned and the associated aversion to Y was measured. We found after rapid intermixed preexposure a reduction in generalization from the aversive Y element to the compound AY (Experiment 1) as well as a reduction in A's salience (Experiments 2 and 3) compared to the effects of blocked preexposure. The results are discussed in terms of the various mechanisms underlying perceptual learning, which appear to depend on the details of the task. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Three experiments explored how training reinforcement schedules and context influence the elimination and recovery of human operant behavior. In Experiment 1, participants learned a discriminated operant response in Context A before the response was eliminated with extinction in Context B. They then received a final test in each context. Groups were trained with a discriminative stimulus that predicted a reinforced response on either every trial (continuous reinforcement [CRF]) or some of the trials (partial reinforcement [PRF]). Extinction was slower following PRF training (a partial reinforcement extinction effect [PREE]) and extinguished responding increased when tested in Context A ("ABA" renewal). Experiment 2 further confirmed the PREE was obtained equally whether extinction occurred in the training context (Context A) or a new context (Context B) which is consistent with trial-based accounts of the PREE. Experiment 3 used the same design as Experiment 1 to evaluate the influence of training reinforcement on response elimination with an omission contingency. Across the omission training phase in Context B, the decrease in responding occurred more slowly in the PRF-trained group in comparison to the CRF-trained group, perhaps the first demonstration of what might be termed a PRF omission effect. Again, ABA renewal was observed in Context A. Training reinforcement schedule therefore had a similar influence on response elimination with extinction and omission. Elimination and recovery of human instrumental behavior, with extinction or omission, are influenced by training reinforcement schedule and context. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

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).

In three experiments, rats were given experience of flavored solutions AX and BX, where A and B represent distinctive flavors and X a flavor common to both solutions. In one condition, AX and BX were presented on the same trial separated by a 5-min interval (intermixed preexposure). In another condition, each daily trial consisted of presentations of only AX or only BX (blocked preexposure). The properties acquired by stimulus X were then tested. Experiment 1 showed that after intermixed preexposure X was less able to interfere with a conditioned response established to a different flavor. Experiment 2 showed that X was less effective at overshadowing when trained in compound with another flavor. Simple conditioning, with X as the conditioned stimulus, was not sensitive to the form of preexposure (Experiment 3). These results indicate that the opportunity to compare similar stimuli that is provided by presenting them in close succession can change the properties of features they hold in common, making these features less effective when tested in compound with other stimuli. A loss of effectiveness by such features would contribute to the perceptual learning effect, the enhancement of subsequent discrimination, that is generated by prior exposure to closely spaced similar stimuli. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Four experiments explored the impact of focused-attention mindfulness training on human performance on free-operant schedules of reinforcement. In each experiment, human participants responded on a multiple random ratio (RR), random interval (RI) schedule. In all experiments, responding was higher on RR than RI schedules, despite equated rates of reinforcement. A 10-min focused-attention mindfulness intervention (focused attention) produced greater differentiation between schedules than relaxation training (Experiments 1, 2, and 4), or no intervention (Experiment 3). Focused-attention mindfulness improved learning when the schedules associated with components of the multiple schedule were reversed. This occurred irrespective of whether the focused-attention mindfulness was before (Experiment 2) or after (Experiments 3 and 4) initial training, or whether compared to relaxation (Experiments 2 and 4) or no intervention (Experiment 3). In Experiment 4, following multiple RR, RI training, focused-attention mindfulness increased sensitivity to contingency reversal and did not interfere with previous training in a group that did not receive a contingency reversal. In contrast, relaxation training did not facilitate reversal learning and interfered with previous learning. The results suggest that focused-attention mindfulness improves awareness of operative contingencies by focusing participants on the present, rather than reducing interference from previous learning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

How do ants resolve conflicts between different sets of navigational cues during navigation? When two cue sets point to diametrically opposite directions, theories predict that animals should pick one set of cues or the other. Here we tested how nocturnal bull ants Myrmecia midas adjust their paths along established routes if route following does not lead to their entry into their nest. During testing, foragers were repeatedly placed back along their homeward route up to nine times, a procedure called rewinding. This procedure produced an accumulating path integrator, or vector, in diametric opposition to the learned landmark views of the route. Repeated rewinding made some individuals head initially in the nest-to-feeder vector direction, but all ants ended up using the visual scene for homing, demonstrating the importance of view-based homing in this species. Repeated rewinding, however, led to path deteriorations; with increased path meander and scanning, results also found in desert ants. After nine rewinding trips, ants were displaced off their route in further manipulations, to a site near the nest, an unfamiliar site, or with the terrestrial surround entirely covered. The results show that a change in visual conditions diminished the weight accorded to path integration: the off-route ants no longer headed off in the vector direction as they did on the immediately preceding trial. They relied on celestial compass cues in other ways for homing. Experiment 2 showed the effects of rewinding in the unaltered natural habitat were not view-specific in these bull ants. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Inhibitory stimuli are slow to acquire excitatory properties when paired with the outcome in a retardation test. However, this pattern is also seen after simple nonreinforced exposure: latent inhibition. It is commonly assumed that retardation would be stronger for a conditioned inhibitor than for a latent inhibitor, but there is surprisingly little empirical evidence comparing the two in either animals or humans. Thus, retardation after inhibitory training could in principle be attributable entirely to latent inhibition. We directly compared the speed of excitatory acquisition after conditioned inhibition and matched latent inhibition training in human causal learning. Conditioned inhibition training produced stronger transfer in a summation test, but the two conditions did not differ substantially in a retardation test. We offer two explanations for this dissociation. One is that learned predictiveness attenuated the latent inhibition that otherwise would have occurred during conditioned inhibition training, so that retardation in that condition was primarily due to inhibition. The second explanation is that inhibitory learning in these experiments was hierarchical in nature, similar to negative occasion-setting. By this account, the conditioned inhibitor was able to negatively modulate the test excitor in a summation test, but was no more retarded than a latent inhibitor in its ability to form a direct association with the outcome. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

In a long operant chamber, pigeons were trained to discriminate between 4-s and 12-s samples in a symbolic matching-to-sample task. Subsequently, delay and no-sample test trials were introduced. The location in the chamber in which the trial started and each comparison was presented varied across three experiments. Our main goals were to assess the effect of the delay and to compare preferences on delayed and no-sample trials. Both pigeons' preferences and their movement patterns were analyzed. In Experiments 1 and 3, pigeons learned to move immediately to the location where the correct comparison would be presented, allowing them to select a comparison at its onset and receive reinforcement. In Experiment 2, some birds moved differently-probably reflecting an interaction of travel distance with outcome certainty. On delay testing, as the delay increased, accuracy decreased and the pigeons tended to move to the middle of the chamber, irrespective if that location was associated with the beginning of the trials or with one of the comparisons. Inserting a delay seemed to lead to a disruption where stimulus control by the sample was reduced and replaced by control by the location at the moment of choice. On no-sample delayed testing, pigeons also showed a tendency to move toward the middle of the chamber, which was combined with a preference for the comparison associated with the short sample. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Temporal information-processing is critical for adaptive behavior and goal-directed action. It is thus crucial to understand how the temporal distance between behaviorally relevant events is encoded to guide behavior. However, research on temporal representations has yielded mixed findings as to whether organisms utilize relative versus absolute judgments of time intervals. To address this fundamental question about the timing mechanism, we tested mice in a duration discrimination procedure in which they learned to correctly categorize tones of different durations as short or long. After being trained on a pair of target intervals, the mice were transferred to conditions in which cue durations and corresponding response locations were systematically manipulated so that either the relative or absolute mapping remained constant. The findings indicate that transfer occurred most readily when relative relationships of durations and response locations were preserved. In contrast, when subjects had to re-map these relative relations, even when positive transfer initially occurred based on absolute mappings, their temporal discrimination performance was impaired, and they required extensive training to re-establish temporal control. These results demonstrate that mice can represent experienced durations both as having a certain magnitude (absolute representation) and as being shorter or longer of the two durations (an ordinal relation to other cue durations), with relational control having a more enduring influence in temporal discriminations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The perception of temporal order can help infer the causal structure of the world. By investigating the perceptual signatures of audiovisual temporal order in rats, we demonstrate the importance of the protocol design for reliable order processing. Rats trained with both reinforced audiovisual trials and non-reinforced unisensory trials (two consecutive tones or flashes) learned the task surprisingly faster than rats trained with reinforced multisensory trials only. They also displayed signatures of temporal order perception, such as individual biases and sequential effects that are well described in humans, and impaired in clinical populations. We conclude that an experimental protocol requiring individuals to process all stimuli in a sequence is compulsory to ensure temporal order processing. (PsycInfo Database Record (c) 2023 APA, all rights reserved).