Learning & Behavior最新文献

In a clever adaptation of the two-cups task, a recent paper tested for reasoning by exclusion in bees. Although further work is necessary to rule out competing hypotheses, this study advances our ability to test cognitive capacities in invertebrates.

Professor Nicola Clayton is perhaps best known for her work on food-caching scrub jays. Her seminal 1998 paper, together with Anthony Dickinson, showed that scrub jays could remember what food they had cached, where and how long ago, suggesting memory ability that is 'episodic-like' in nature. Here, we present data from a previously unpublished study that sought to replicate and extend these findings. The results replicate previous findings and address potential alternative explanations for earlier results. We argue that the controlled behavioural analyses introduced in this study have the potential to add nuance to our understanding of memory in scrub jay cache retrieval, and to inspire new studies exploring this phenomenon, about which we still have so much to learn.

The perception of objects is a challenging task that requires recognizing visual elements and integrating them into a whole. While human vision prioritizes attention to the overall configuration, data from other species suggests this bias towards global form perception is not universal. Studies with pigeons indicate preferential attention to local details when both local and global information may be diagnostic, but studies with other bird species are more limited. To examine whether this local bias is class-wide or potentially species-specific, we studied whether African grey parrots (Psittacus erithacus) have a bias towards local elements or the global configuration when processing Navon-like hierarchical form displays. Two parrots were tested using a computerized touch-screen two-alternative choice task that presented displays that were local-relevant or global-relevant. The results of several successive acquisition phases suggest that these parrots have no local or global bias, indicating differing evolutionary or ecological drives for visual processing among avian species.

A recent study demonstrated that marmoset "phee calls" include information specific to the intended receiver of the call, and that receivers respond more to calls that are specifically directed at them. The authors interpret this as showing that these calls are name-like vocal labels for individual marmosets, but there is at least one other possibility that would equally explain these data.

A decrease in the rate of reinforcement associated with one component of a multiple schedule is typically associated with a decrease in responding in that component as well as with an increase in responding in the unchanged component. This increase in responding, referred to as positive contrast, is thought to result from an increase in the subjective value associated with the unchanged component. Williams Animal Learning & Behavior, 19, 337-344, (1991) challenged this hypothesis in an experiment with pigeons in which Stimulus A, associated with a variable interval schedule, was always followed by Stimulus X, associated with extinction, while Stimulus B, associated with the same variable interval schedule, was always followed by Stimulus Y, also associated with a variable interval schedule. Although Williams found that most of the pigeons pecked more at Stimulus A than at Stimulus B (behavioral contrast), when the pigeons were given a choice between Stimulus A and B, they showed a preference for Stimulus B. In the present experiment (a slight modification from Williams's), we confirmed this finding. Although our pigeons pecked more at Stimulus A than at Stimulus B, they generally preferred Stimulus B, the stimulus that was not followed by extinction. This result suggests that positive contrast may not result from an increase in the subjective value of the unchanged component. Instead, it suggests that this version of positive contrast may result at least in part from the pigeons' attempt to get all of the reinforcers possible in the presence of Stimulus A before the extinction schedule begins.

This study explored long-term retention of spatial memory in rats using an eight-arm radial maze. Crystal and Babb (Learning and motivation, 39(4), 278-284, 2008) previously demonstrated that rats could retain spatial memory for up to 25 h in the radial maze. Notably, they found performance improved with 48-h intertrial intervals compared with 24-h intervals. Our study investigated the effects of extending intertrial intervals on long-term retention of spatial memory by reducing the potential for proactive interference. Each trial comprised a learning phase, during which subjects were required to sequentially visit four randomly selected arms, followed by a free-choice test that included all eight arms, conducted after increasing the retention and intertrial intervals. The retention intervals were systematically increased from 1 h to 24, 48, and, ultimately, 72 h, with corresponding intertrial intervals expanding from 24 to 48, 120, and 144 h. Performance significantly surpassed chance levels across all conditions, demonstrating that rats are capable of retaining spatial memory for up to 72 h.

In a noteworthy observation, Godfrey-Smith and colleagues report the first evidence of debris throwing in wild octopuses, including instances where they target conspecifics. Proposing parallels with behaviours observed in select social mammals, this discovery prompts inquiries into the extent of their similarity and the potential role of cognition.

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.