The face of animal cognition

Adding the neuro to cognition: from food storing to nest building

Typically, investigations of animal cognition couple careful experimental manipulations with examination of the animal's behavioural responses. Sometimes those questions have included attempts to describe the neural underpinnings of the behavioural outputs. Over the past 25 years, behaviours that involve spatial learning and memory (such as navigation and food storing) has been one context in which such dual or correlated investigations have been both accessible and productive. Here I review some of that work and where it has led. Because of the wealth of data and insights gained from that work and song learning before it, it seems that it might also be useful to try to add some neurobiology to other systems in animal cognition. I finish then, with a description of recent work on the cognition and neurobiology of avian nest building. It is still relatively early days but asking questions about the cognition of nest building has already shown both neural correlates of nest building and that learning and memory play a much greater role in this behaviour than previously considered. While it is not yet clear how putting these components together will be synergistic, the examples of song learning and food storing provide encouragement. Perhaps this might be true for other behaviours too?

Anuran interorbital distance variation: the role of ecological and behavioral factors

Eye position varies significantly among taxonomic levels, and this variation is often shaped by ecological and behavioral factors. Eye position is often positively associated with interorbital distance where species with broad visual fields possess a large distance between the left and right eye. Selective pressures underlying the evolution of the eye position are especially studied in birds and mammals. However, selective pressures underling the evolution of anuran eye position which can be indicated by interorbital distance keep unknown. Here, we investigated the effects of ecological (e.g., habitat type, light availability) and behavioral factors (e.g., activity pattern, foraging mobility, and defensive strategy) on variations in interorbital distance among 260 anuran species in China. Our results showed that variations of the interorbital distance can be significantly predicted by the activity pattern. Nocturnal species had larger interorbital distance than both nocturnal and diurnal species. We also found that foraging mobility and defensive strategy affected markedly variation of interorbital distance. Species having slower foraging mobility and possessing poison glands had larger interorbital distance than species having faster foraging mobility and possessing non-position glands. Light availability tended to be associated with variation of interorbital distance, indicating that species living weak light tending to possess larger interorbital distance. However, variations of the interorbital space were not associated with habitat type in anurans. Our findings suggest that anuran behaviors play key roles in shaping visual fields and eye position, and thus affecting the evolution of interorbital distance. This article is protected by copyright. All rights reserved.

Reinstating reptiles: from clueless creatures to esteemed models of cognitive biology

Non-avian reptiles have long been neglect in cognitive science due to their reputation as slow and inflexible learners, but fortunately, this archaic view on reptile cognition is changing rapidly. The last two decades have witnessed a renewed interest in the cognitive capacities of reptiles, and more ecologically relevant protocols have been designed to measure such abilities. Now, we appreciate that reptiles possess an impressive set of cognitive skills, including problem-solving abilities, fast and flexible learning, quantity discrimination, and even social learning. This special issue highlights current research on reptiles in cognitive biology and showcases the diversity of research questions that can be answered by using reptiles as study model. Here, we briefly address (the key results of) the contributing articles and their role in the endeavour for total inclusion of reptiles in cognitive biological research, which is instrumental for our understanding of the evolution of animal cognition. We also discuss and illustrate the promising potential of reptiles as model organisms in various areas of cognitive research.

Extrinsic stressors modulate resource evaluations: insights from territoriality under artificial noise

Background

Competition is considered to rely on the value attributed to resources by animals, but the influence of extrinsic stressors on this value remains unexplored. Although natural or anthropogenic environmental stress often drives decreased competition, assumptions that this relies on resource devaluation are without formal evidence. According to theory, physiological or perceptual effects may influence contest behaviour directly, but motivational changes due to resource value are expected to manifest as behavioural adjustments only in interaction with attainment costs and resource benefits. Thus, we hypothesise that stressor-induced resource devaluations will impose greater effects when attainment costs are high, but not when resource benefits are higher. Noise may elicit such effects because it impacts the acoustic environment and imposes physiological and behavioural costs to animals. Therefore, we manipulated the acoustic environment using playbacks of artificial noise to test our hypotheses in the territorial male Siamese fighting fish, Betta splendens.

Results

Compared to a no-playback control, noise reduced defense motivation only when territory owners faced comparatively bigger opponents that impose greater injury costs, but not when territories also contained bubble nests that offer reproductive benefits. In turn, nest-size decreases were noted only after contests under noise treatment, but temporal nest-size changes relied on cross-contest variation in noise and comparative opponent size. Thus, the combined effects of noise are conditional on added attainment costs and offset by exceeding resource benefits.

Conclusion

Our findings provide support for the hypothesised modulation of resource value under extrinsic stress and suggest implications for competition under increasing anthropogenic activity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12983-021-00397-x.

Weber's Law and the Scalar Property of Timing: A Test of Canine Timing

Simple Summary

Understanding the perceptual abilities of companion animals such as dogs adds to our understanding of the cognitive abilities of non-human animals. This study assessed the time perception abilities of dogs. In this study, dogs were required to identify whether the duration of a light was of a short or long duration by pressing a response lever. Dogs were able to correctly classify the durations as short or long. When given durations that were intermediate of the original short and long stimuli, their performance approached chance levels near the middle of the short and long durations. The performance of dogs on this task was similar to other animals, such as rats, pigeons and possums. Aspects of their performance also challenged some long-held assumptions of existing models of time perception. Research that assesses the cognitive abilities of dogs remains a fertile area of research that will improve our understanding about their abilities and limits.

Abstract

Domestic dogs completed a temporal bisection procedure that required a response to one lever following a light stimulus of short duration and to another lever following a light stimulus of a longer duration. The short and long durations across the four conditions were (0.5–2.0 s, 1.0–4.0 s, 2.0–8.0 s, and 4.0–16.0 s). Durations that were intermediate, the training durations, and the training durations, were presented during generalization tests. The dogs bisected the intervals near the geometric mean of the short and long-stimulus pair. Weber fractions were not constant when plotted as a function of time: A U-shaped function described them. These results replicate the findings of previous research reporting points of subjective equality falling close to the geometric mean and also confirm recent reports of systematic departures from Weber’s law.