Learning & Behavior最新文献

Bielecki et al. Current Biology, 33, 4150-4159, (2023) described new behavioral and physiological paradigms to study associative learning and its neural basis in the Cnidaria Tripedalia cystophora. We discuss the relevance of these findings to further our understanding of the intertwined evolution of cognition and the nervous systems.

In general, animals are known to be sensitive to the immediacy of reinforcers. That is, they are generally impulsive and outcomes that occur in the future are generally heavily discounted. Furthermore, they should prefer alternatives that provide reinforcers that require less rather than greater effort to obtain. In the present research, pigeons were given a choice between (1) obtaining reinforcers on a progressively more difficult schedule of reinforcement; starting with four pecks, then eight pecks, then 16 pecks, then 32 pecks, and finally 64 pecks on each trial, and (2) a color signaling a number of pecks for a single reinforcer: red = six, green = 11, blue = 23, or yellow = 45. If pigeons choose optimally, most of the time they should choose the progressive schedule to obtain five reinforcers rather than switch to a color to receive only one. However, if they are sensitive primarily to the number of pecks to the next reinforcer, they should choose the progressive schedule once before switching to red, twice before switching to green, three times before switching to blue, and four times before switching to yellow. Instead, they systematically switched too early. Rather than choose based on the rate of reinforcement or even based on the time or effort to the next reinforcer, they appear to anticipate that the progressive schedule is going to get more difficult, and they base their choice suboptimally on the serial pattern of the worsening progressive schedule.

The aim of this research was to test the effect of training impure tact versus pure tact and intraverbals on the emergence of new verbal operants (impure tacts), thus establishing a conceptual and methodological differentiation on these operants. This was done by varying the training order of intraverbal or impure tact to analyze and confirm whether or not impure tact is the mere sum of pure tact plus intraverbal and therefore has different functions and consequences in learning. An experiment was conducted with 30 participants randomly assigned to three groups. In Group 1, pure tact plus intraverbal and then impure tact were trained. In Group 3 the training order of these operants was counterbalanced. Group 2 was the control group, training only pure tact plus intraverbal. After the training phases, the emergence of impure tacts was tested. The results of this research indicate that the training of impure tacts favors the emergence of new impure tacts to a greater extent than the training of pure tact plus intraverbal and that they therefore have different functions. It is also shown that variation in the order of presentation of the type of training influences the subsequent emergence of new operants (impure tacts), so that creating a previous history of learning in impure tacts favors emergence even when the intraverbal alone is subsequently trained. This has important implications at both conceptual and methodological levels as it would contribute to the development of more effective language training technologies.

A recent paper Smulders et al., (2023) analyzed results of an experiment in which food-caching coal tits needed to relocate and recover multiple previously made food caches and argued that food caching parids use familiarity and not recollection memory when recovering food caches. The memory task involving recovery of multiple caches in the same trial, however, cannot discriminate between these two memory mechanisms because small birds do not need to recover multiple caches to eat during a single trial. They satiate quickly after eating just the first recovered food cache and quickly lose motivation to search for caches, and can be expected to start exploring noncache locations rather than recovering the remaining caches, which would result in inaccurate memory measurements.

To survive and reproduce, animals need to behave adaptively by adjusting their behavior to their environment, with learning facilitating some of these processes. Dogs have become a go-to model species in comparative cognition studies, making our understanding of their learning skills paramount at multiple levels, not only with regards to basic research on their cognitive skills and the effects of domestication, but also with applied purposes such as training. In order to tackle these issues, we tested similarly raised wolves and dogs in a serial learning task inspired by Harlow's "learning set." In Phase 1, different pairs of objects were presented to the animals, one of which was baited while the other was not. Both species' performance gradually improved with each new set of objects, showing that they "learnt to learn," but no differences were found between the species in their learning speed. In Phase 2, once subjects had learned the association between one of the objects and the food reward, the contingencies were reversed and the previously unrewarded object of the same pair was now rewarded. Dogs' performance in this task seemed to be better than wolves', albeit only when considering just the first session of each reversal, suggesting that the dogs might be more flexible than wolves. Further research (possibly with the aid of refined methods such as computer-based tasks) would help ascertain whether these differences between wolves and dogs are persistent across different learning tasks.

One of Clayton’s major contributions to our understanding of animal minds has been her work on episodic-like memory. A central reason for the success of this work was its focus on ecological validity: rather than looking for episodic memory for arbitrary stimuli in artificial contexts, focussing on contexts in which episodic memory would serve a biological function such as food caching. This review aims to deepen this insight by surveying the numerous functions that have been proposed for episodic memory, articulating a philosophically grounded framework for understanding what exactly functions are, and drawing on these to make suggestions for future directions in the comparative cognitive psychology of episodic memory. Our review suggests four key insights. First, episodic memory may have more than one function and may have different functions in different species. Second, cross-disciplinary work is key to developing a functional account of episodic memory. Third, there is scope for further theoretical elaboration of proposals relating episodic memory to food caching and, in particular, future-oriented cognition. Finally, learning-related functions suggested by AI (artificial intelligence)-based models are a fruitful avenue for future behavioural research.

Despite birdsong being one of the most studied models of sexual selection, how it operates in birds that sing only one song remains poorly understood. A recent study using a big data approach reveals a novel aspect of song that may potentially function as an honest signal of male quality and a way to maintain listener attention.

The “Spoon task” is a common measure of episodic future thinking (i.e., ability to imagine hypothetical future events) in children. However, by providing items and prompting children to choose one, this task might not require deliberate and goal-driven episodic future thinking. In contrast, “spontaneous” Spoon tasks may better reflect Tulving’s original conception as they minimize environmental cues and verbal prompts. We identify challenges in designing such tasks, including removing the scaffolded intention to act and giving children permission and sufficient motivation to act. Drawing on the comparative literature, we propose methods to overcome these obstacles when designing spontaneous Spoon tasks. Furthermore, sampling from the work of Clayton and colleagues, we advocate for a multipronged approach including two or more of the following methods in order to capture spontaneous behavior: naturalistic observation, virtually administered tasks within the child’s home, laboratory experiments, and questionnaires. Our review highlights the importance of spontaneous episodic future thinking and establishes a foundation for future methodologies to study this complex cognitive process.

Researchers have recently described the wing-fluttering signal of Japanese tits and eyeblink signal of concave-eared torrent frogs as bodily communication that elicits specific responses. I assess the evidence that these may be intentional, goal-directed signals using established criteria for gestural communication.

Category learning is often tested with similar images that have no significance outside of the experiment for the subjects. By contrast, in nature animals often need to generalize a behavioral response like "eat" across visually distinct stimuli, such as spiders and seeds. Forming functional categories like "food" and "predator" may require conceptual rather than purely perceptual generalization. We trained free-range chickens to classify images assigned to one of four categories based on putative functional significance: inanimate objects, predators, food, and non-competing vertebrates. Images were visually diverse within each category, discouraging classification by perceptual similarity alone. In Experiment 1, chickens classified 80 images into four categories. Chickens then generalized to 80 new exemplars in each of three successive generalization tests. In Experiment 2, chickens saw new types of images to test whether their generalization was perceptual or functional. For example, chickens saw images of skunks for the predator category after training with images of hawks and snakes. Chickens used the "predator" response with these new images for both predators and non-threatening vertebrates, but not for objects or food, and did not successfully generalize any category other than predator. In Experiment 3, chickens categorized fractals as "food," and three of four chickens categorized a range of vertebrates they had not previously encountered as "predators," suggesting that chickens did not see the images as representing real world objects and animals. These results highlight constraints on the use of computer-generated images to assess categorization of natural stimuli in chickens.