Learning & Behavior最新文献

In a recent study, Johnson and Wynne found that dogs classically conditioned to associate electric shocks with chasing a fast-moving mechanical lure inhibited chasing behaviour at test, while dogs conditioned with food rewards did not learn any operant behaviours to substitute chasing and therefore continued to interact with the lure. Here, we raise questions about the suitability of the training protocols and challenge the conclusion that shock collars impose minimal welfare impacts.

A new study investigates how stingless bee colonies inherit one of two architecturally distinct types of comb and proposes the primary mechanism of inheritance as stigmergy: among-individual coordination in comb building informed by environmental cues (i.e., social artefacts). These findings highlight the importance of social information in creating and maintaining architectural variance among structures.

Disgust is a basic emotion that motivates avoidance behaviors to protect organisms from pathogens. Objects of disgust are acquired through classical conditioning mechanisms. Oculomotor avoidance serves as an objective marker of disgust, yet previous studies have relied on repeated presentations to establish disgust conditioning. This study aimed to adapt the category-conditioning paradigm (Dunsmoor et al., Cerebral Cortex, 24, 2859-2872, 2014) for disgust learning by employing trial-unique presentations, offering a novel tool for future research. In our experiment, items of two categories - furniture and vehicles - were paired with either disgusting or neutral scenes. Participants' eye movements were tracked, and self-reported measures were collected. The results demonstrated that the category-conditioning task with trial-unique stimuli effectively induced oculomotor avoidance. Participants exhibited both unconditioned avoidance responses to disgusting scenes and conditioned avoidance responses to category items associated with disgust. Eye-tracking data further revealed that disgust-associated stimuli motivated avoidance beyond their role as mere predictors of an aversive stimulus. Interestingly, participants initially exhibited a tendency to view the disgusting image before engaging in avoidance behavior. In conclusion, this study demonstrates that the adapted category-conditioning paradigm successfully elicits conditioned responses using trial-unique stimuli. We believe that this paradigm will provide a valuable tool for future research on disgust learning.

Research has examined how stimulants affect impulsive choice in delay-discounting tasks, but little is known about whether such drugs influence how discounting varies with reward magnitude. This study sought to investigate the effects of acute and chronic methamphetamine administration on rats' responding in a rapid acquisition choice task in which reward delays were changed unpredictably across sessions. In each group of four sessions, delays were unequal (1 s/8 s, or 8 s/1 s) or equal (1 s/1 s, or 8 s/8 s) while reward magnitudes were constant and unequal (one dipper cycle/four dipper cycles). This enabled us to obtain both estimates of delay discounting (i.e., sensitivity to delay) and the magnitude effect (in which larger rewards are discounted at a lower rate). Methamphetamine was administered in increasing doses acutely and chronically. Baseline results showed that rats reliably preferred the alternative with a shorter delay and that choice for the larger reward was greater when the delays were long, consistent with the magnitude effect. Acute methamphetamine dose dependently reduced both sensitivity to delay and the magnitude effect, but not sensitivity to magnitude. Chronic administration had no systematic effect on choice. This study is the first to report a magnitude effect with rats in a rapid acquisition choice procedure similar to that found in delay discounting research with humans, and suggests that acute methamphetamine administration reduces control by contingencies that change across sessions.

Townrow and Krupenye (PNAS, 122(6), Article e2412450122, 2025) found that bonobos understand the mental states of others and can attribute ignorance to a social partner. In an elegantly simple design, the authors found bonobos to communicate more often, and more quickly, when a social partner is ignorant, rather than knowledgeable, of the location of a hidden food item.

New research is shedding light on the nuances and complexity of social relationships in our closest relatives, revealing cooperative intergroup relationships in bonobos, in contrast to lethal intergroup violence in chimpanzees. At the same time, intragroup relationships, at least among males, are characterized by higher frequencies of aggression and lower rates of coalitionary cooperation in bonobos than chimpanzees.

Although the diversification of species has fascinated researchers for centuries, we know remarkably little about how behavior influences niche adaptation and the genetic mechanisms through which behavior evolves. In their recent study, Sommer-Trembo et al. (Science, 384, 470-475, 2024) demonstrate a critical role for the regulatory gene cacng5b in modulating phenotypic variation in exploratory behavior in one of the most exceptional adaptive radiations: the African cichlid fishes of Lake Tanganyika.

Recent findings indicate that noise pollution - presented in the absence of other variables - has both immediate-term impacts on young birds' developmental rates and physiology as well as long-term effects on adult telomere length and reproductive success. This work highlights yet another set of negative impacts caused by anthropogenic noise, and suggests that the dramatic fitness consequences observed likely have implications for the evolution of learning and behavior in animals living in noisy environments.

Domestic dogs (Canis familiaris) have been documented to 'overimitate' humans - a form of social learning - by copying their causally-irrelevant actions. It is suggested that this behaviour results from social, affiliative motivations. Dogs have also been known to behave differently when they are being watched (or not) by humans, such as by following commands better (or worse). In this study, we tested whether dogs' copying behaviour would also be sensitive to their caregiver's attentional states. The subject's caregiver demonstrated irrelevant and relevant actions in the dot-touching overimitation task, then during trials the caregiver was either watching their dog or turned away. Our results revealed no difference in dogs' irrelevant-action copying; however, we found that dogs approached the dots less per trial when their caregiver was watching them. Dogs also copied their caregiver's leftward sliding of a door (to obtain a food reward) more accurately when they were being watched by their caregiver. Finally, dogs who copied the irrelevant action did so more often after obtaining their food reward, which supports that these dogs may have had two separate goals: a primary instrumental goal and a secondary social goal.