Learning & Behavior最新文献

Here, we address Hansen Wheat et al.'s commentary in this journal in response to Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021). We conduct additional analyses in response to Hansen Wheat et al.'s two main questions. First, we examine the claim that it was the move to a human home environment which enabled the dog puppies to outperform the wolf puppies in gesture comprehension tasks. We show that the youngest dog puppies who had not yet been individually placed in raisers' homes were still highly skilled, and outperformed similar-aged wolf puppies who had higher levels of human interaction. Second, we address the claim that willingness to approach a stranger can explain the difference between dog and wolf pups' ability to succeed in gesture comprehension tasks. We explain the various controls in the original study that render this explanation insufficient, and demonstrate via model comparison that the covariance of species and temperament also make this parsing impossible. Overall, our additional analyses and considerations support the domestication hypothesis as laid out by Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021).

A recent publication analyzing data collected by citizen scientists on the rufous hornero (Furnarius rufus) revealed consistent among-individual variation in nest asymmetry (left vs. right entrance). We summarize this result and discuss: (1) nest building as a useful model system to study different questions, and, (2) what the repeatability found in the featured paper could reveal regarding nest-building decisions.

The relative importance of adaptation and individual ontogenetic experience in dogs' high levels of behavioral compatibility with humans has been a topic of intense scientific attention over the past two decades. Salomons et al. Current Biology, 31, 3137-3144, (2021) recently presented a particularly rich data set of observations on both wolf and dog puppies that has the potential to contribute substantially to this debate. In their study subjecting wolf and dog puppies to batteries of tests, including the ability to follow human pointing gestures, Salomons et al. (2021) reported that dogs, but not wolves, have a specialized innate capacity for cooperation with humans. However, upon reanalyzing this data set, we reach a different conclusion-namely, that when controlling adequately for various environmental factors, wolves and dogs perform similarly in their cooperation with humans.

When pigeons learn matching-to-sample or nonmatching-to-sample there is good evidence that they can transfer that learning to novel stimuli. But early evidence suggests that in the rate of task acquisition, there is no benefit from a matching relation between the sample and the correct or incorrect comparison stimulus. In the present research we trained three groups of pigeons, each on two two-stimulus tasks simultaneously, matching-matching, nonmatching-nonmatching, or matching-nonmatching. If a common matching or nonmatching relationship benefits acquisition, the first two groups should acquire their tasks faster than the third group, for which the two tasks ought to be incompatible. The results indicated that all three groups acquired their tasks at about the same rate. A secondary goal of the experiment was to determine the basis of learning for the each of the three groups. During testing, for each task, there were test trials in which one of the stimuli from the other task replaced either the correct or the incorrect comparison stimulus. Surprisingly, neither comparison stimulus appeared to show complete control over comparison choice. Although replacing either comparison stimulus resulted in a decrement in task accuracy from about 90% to 70% correct, independent of which comparison stimulus was replaced, the pigeons chose correctly at well above chance accuracy. Suggestions to explain this unexpected outcome are discussed.

It is well established that decay and interference are the two main causes of forgetting. In the present study, we specifically focus on the impact of interference on memory forgetting. To do so, we tested Guinea baboons (Papio papio) on a visuo-motor adaptation of the Serial Reaction Time task in which a target sequence is repeated, and a random sequence is interposed between repetitions, a similar situation as the one used in the Hebb repetition paradigm. In this task, one three-item sequence, the repeated sequence, was presented every second trial and interleaved with random sequences. Interference was implemented by using random sequences containing one item that was also part of the repeated sequence. In a first condition, the overlapping item was located at the same position as the repeated sequence. In a second condition, the overlapping item was located at one of the two other positions. In a third condition, there was no overlap between repeated and random sequences. Contrary to previous findings, our results reveal similar learning slopes across all three conditions, suggesting that interference did not affect sequence learning in the conditions tested. Findings are discussed in the light of previous research on sequence learning and current models of memory and statistical learning.

While humans exposed to a sequential stimulus pairing A-B are commonly assumed to form a bidirectional mental relation between A and B, evidence that non-human animals can do so is limited. Careful examination of the animal literature suggests possible improvements in the test procedures used to probe such effects, notably measuring transfer effects on the learning of B-A pairings, rather than direct recall of A upon cuing with B. We developed such an experimental design and tested 20 Guinea baboons (Papio papio). Two pairings of visual shapes were trained (A1-B1, A2-B2) and testing was conducted in a reversed order, either with conserved pairings (B1-A1, B2-A2) or broken ones (B1-A2, B2-A1). We found baboons' immediate test performance to be above chance level for conserved pairings and below chance level for broken ones. Moreover, baboons needed less trials to learn conserved pairings compared to broken ones. These effects were apparent for both pairings on average, and separately for the best learned pairing. Baboons' responding on B-A trials was thus influenced by their previous A-B training. Performance level at the onset of testing, however, suggests that baboons did not respond in full accordance with the hypothesis of bidirectionality. To account for these data, we suggest that two competing types of relations were concomitantly encoded: a directional relation between A and B, which retains the sequential order experienced, and a non-directional relation, which retains only the co-occurrence of events, not their temporal order.

In two experiments, rats observed expert foragers in a laboratory foraging task. In both experiments, 12 towers with a food cup on top of each tower were placed in a circle. Six towers, marked with black and white stripes, had cups baited with cheese, and were located in randomly selected positions on successive trials. The other six towers were white with food cups that were sham baited with inaccessible food. In both experiments, during Phase 1, demonstrator rats eventually learned to find the baited towers, making approximately 90% correct choices in their first six choices. In Phase 2, observer rats each had an opportunity to observe, from a cage located inside the circle of towers, a now-expert demonstrator forage. Half of the observers were able to observe a cage mate, whereas the other half of the observers were able to observe a non-cage mate. After a delay of about 2 min (Experiment 1) or about 24 h (Experiment 2), the observers were allowed to forage among the rebaited towers. In both experiments, the observers performed better during their 20 Phase 2 trials than the demonstrators had performed during their first 20 Phase 1 trials. But, in both experiments, there was no clearly significant difference between the performance of observers able to watch cage mates as opposed to non-cage mates. Because the observational effect seen in both experiments survived a 24-h delay between observation and performance, it was deemed to have been based on learning.

Cooperative behavior represents a situation in which individuals sometimes act in a way that produces a gain to another at a cost to themselves. This may be explained by a history of repeated interactions with others in which such behavior has resulted in reciprocal cooperation from others. Sometimes, even with reciprocal cooperation, gains and costs are unbalanced between partners. In this case, there is evidence that people may present an aversion to both disadvantageous and advantageous distributions of gains. In other words, they may act in such a way as to ensure an equal outcome among all group members. Aversion to inequity that benefits oneself (advantageous inequity (AI) aversion) may be more dependent on social and cultural cues than aversion to inequity that benefits others (disadvantageous inequity (DI) aversion). Using both between-subjects (Experiment 1) and within-subjects (Experiment 2) manipulations, the influence of recent experience with AI on participants' willingness to produce DI was explored within the context of a two-player card game. In initial game phases, the percentage of trials in which the participant experienced AI was manipulated. In subsequent game phases, participants had the opportunity to produce DI to themselves. The results from both experiments suggest that aversion to DI is reduced by recent experience with AI. This procedure allows social influences on DI to be tested, which may be important for providing a psychological explanation of cultural differences in aversion to DI.

Same/different concept learning has been demonstrated in previous research in rats using matching- and non-matching-to-sample procedures with olfactory stimuli. In Experiment 1, rats were trained on the non-matching-to-sample procedure with either three-dimensional (3D plastic objects; n = 3) or olfactory (household spices, n = 5) stimuli, then tested for transfer to novel stimuli of the same, and then the alternate, modality. While all three rats trained with olfactory stimuli showed generalized non-matching to novel odors, only one rat learned the 3D relation and showed generalized transfer to novel objects. Importantly, in this rat the 3D non-matching relation then immediately transferred to odors. In contrast, rats trained with scents did not show transfer to novel 3D stimuli until after training with one or two 3D stimulus sets. In Experiment 2, four rats were trained on an incrementing non-matching-to-sample task featuring 3D plastic objects as stimuli (3D Span Task). Responses to session-novel stimuli resulted in reinforcement. Only two rats learned the 3D Span Task; one rat performed with high accuracy even with up to 17 session-novel objects in a session. While these findings emphasize the exceptional olfactory discrimination of rats relative to that with 3D/tactile/visual cues, they also show that relational learning can be demonstrated in another modality in this species. Further, the present study provides some evidence of cross-modal transfer of relational responding in rats.

Sehner et al. (PNAS Nexus, 2022, 1-14) report that groups of common marmosets solve problems more frequently and faster than individuals working alone. This result is partially explained by greater persistence at the task in the group context and may have important implications for the evolution of cognition and culture.