Biology subjects

Monteiro, T.

Publications and source records attributed to Monteiro, T..

9 recordsLinked to original sources

bioRxiv2026

From wag to affect: Tail kinematic signatures of canine emotional states in computer-controlled environments

From facial expressions to gestures, animals use multiple signal modalities to express emotions and communicate. In dogs, tail movements are conspicuous behaviours associated with emotional states, but this link remains debated. We investigated canine emotional states underlying tail wagging by systematically analysing differences in tail movements in a computer-controlled task encompassing two non-social Conditions - Rewarded (positive) and Unrewarded (negative), and two Epochs (pre-response and outcome anticipation). Using pose-tracking we found that 11 out of 23 dogs did not wag their tails in at least 75% of trials, suggesting that some dogs may inherently wag less or that tail wagging is primarily a social signal. Our results showed that dogs were more likely to wag during positive anticipation; whereas in the negative condition, despite tail amplitude being more prominent, increased speeds reflected arousal rather than valence. Further work should assess tail kinematics in social contexts to test and extend these findings.

animal behavior and cognition↗

bioRxiv2025

Demonstrating inferential reasoning through behavioural choices: an experimental analysis

Is human language necessary for logical reasoning? Multiple studies address this by showing animals a bait hidden in either of two inverted cups, briefly lifting one exposing its content and then letting subjects choose. Consistent preference for the baited container is interpreted as evidence of inferential reasoning by exclusion ("if the bait is not here, it must be there"). More complex variations invoke metacognitive revision of hypotheses. We show that these protocols do not demonstrate logical reasoning. Instead, each event-stimulus elicits different actions and this suffices to choose correctly between them. We demonstrate this with experimental starlings and argue that other species may show similar behaviour, highlighting the need for careful controls when attributing high-level mental capacities such as reasoning or causal understanding.

animal behavior and cognition↗

bioRxiv2024

Do goldfish like to be informed?

Most mammalian and avian species tested so far, including humans, prefer foretold over unsignalled future events, even if the information is costly and confers no direct benefit, a phenomenon that has been called paradoxical, or suboptimal choice. It is unclear whether this is an epiphenomenon of taxonomically widespread mechanisms of reinforcement learning, or if information-seeking is a dedicated cognitive trait, perhaps a precursor of human curiosity. We investigate whether a teleost fish that shares basic reinforcement learning mechanisms with birds and mammals also presents such preference, with the aim of dissociating food-reinforced learning from information-seeking. Goldfish chose between two alternatives, both yielding a 50% chance of reward 5s after being chosen. The informative alternative caused immediate onset of either of two stimuli (S+ or S-) correlated with the trials forthcoming outcome (reward/no reward). Choosing the non-informative option, instead triggered either of two uncorrelated stimuli (N1 or N2). Goldfish learned to discriminate between the different contingencies, but did not develop preference for the informative option. This shows that conditioning learning is not always sufficient, and the difference with birds and mammals supports the hypothesis that information-seeking, rather than simple conditioning, causes the paradoxical preference for unusable information shown by the latter.

animal behavior and cognition↗

bioRxiv2023

Dorsolateral striatum encodes a temporal basis for the organization of behavior

To behave adaptively, the brain must register temporal structure in the environment and use it to organize behavior. The dorsolateral striatum (DLS) integrates sensorimotor input, and is necessary for accurate timing and structuring behavior in general. However, if DLS provides the basis for mapping temporal features in the environment to behavior, its activity should predict variation in that mapping. A reanalysis of DLS population activity in rats comparing the duration of two sequentially presented vibratory stimuli revealed a striking correspondence between neural activity and behavior. Varying vibration intensity of the second stimulus induced systematic biases in temporal judgments, and corresponding biases in multiple features of DLS activity during stimulus presentation, including population coding of time. In contrast, the same intensity manipulations applied to the first stimulus affected neither behavior nor neural activity. Furthermore, neuronal response profiles were best described as a continuum, arguing against hypotheses where categories of responses, e.g., ramping activity, selectively underpin temporal processing. These data represent important additional evidence that striatal population dynamics support the organization of behavior by mapping temporal information to action.

neuroscience↗

bioRxiv2023

Going back to 'basics': Harlow's learning set task with wolves and dogs

To survive and reproduce, animals need to behave adaptively by adjusting their behavior to their environment, with learning facilitating some of these processes. Despite the fact that dogs were the subject species for Pavlovs original studies on learning, relatively little research has been done exploring dogs basic learning capabilities, and even fewer focused on the impact evolution may have had on this behavior. In order to investigate the effects of dog domestication on instrumental learning, we tested similarly-raised wolves and dogs in Harlows "learning set" task. In Experiment 1, several 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 Experiment 2 addressing reversal learning, 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 proved to be better than wolves, albeit only when considering just the first session of each reversal, suggesting that either the dogs had not learned the previous association as well as the wolves or that dogs are more flexible than wolves. Further research (possibly with the aid of refined methods such as touchscreens) would help ascertain whether these differences between wolves and dogs are persistent across different learning tasks.

animal behavior and cognition↗

bioRxiv2022

GoFish: A low-cost, open-source platform for closed-loop behavioural experiments on fish

Fish are the most species-rich vertebrate group, displaying vast ecological, anatomical and behavioural diversity, and therefore are of major interest for the study of behaviour and its evolution. Despite this, with respect to other vertebrates, fish are relatively underrepresented in behavioural research. This is partly due to the difficulty of implementing stimuli, manipulanda, and data recording underwater, meaning that this is frequently done with gates to control subjects, physical displays as stimuli, and visual annotation of videos to record data. To overcome these restrictions we developed GoFish, a fully-automated platform for behavioural experiments. GoFish includes real-time video tracking of subjects, presentation of stimuli in a computer screen, an automatic feeder device, and closed-loop control of task contingencies and data acquisition. The design and software components of the platform are freely available, while the hardware is widely available and relatively inexpensive. The control software, Bonsai, is user-friendly and supported by a growing community of users. As an illustration and test of its use, we present the results of 2 experiments on discrimination learning, reversal, and choice in goldfish (Carassius auratus). GoFish enables the relatively easy implementation of high-throughput tasks and the acquisition of rich behavioural data. Our platform has the potential to become a widely used tool that facilitates complex behavioural experiments in aquatic species.

animal behavior and cognition↗

bioRxiv2021

Uncertainty avoidance versus conditioned reinforcement: exploring paradoxical choice in rats

Paying a cost to reduce uncertainty can be adaptive, because better informed decision-makers can align their preferences to opportunities. However, birds and mammals display an appetite for information that they cannot use to functionally alter behaviour or its outcomes. We explore two putative motivational mechanisms for this paradoxical behaviour. The information hypothesis, proposes that reducing uncertainty is reinforcing per se, consistent with the concept of curiosity: a motivation to know, in the absence of instrumental benefits. In contrast, the conditioned reinforcement hypothesis sees information-seeking as a consequence of asymmetries in secondarily acquired reinforcement: responding increments caused by post-choice stimuli announcing positive outcomes (S+) exceed decrements caused by stimuli signalling absence of reward (S-). We contrast these hypotheses experimentally. Rats chose between two equally profitable options delivering food probabilistically after a fixed delay. In the informative option (Info), the outcome (food/no food) was signalled immediately after choice, whereas in the non-informative option (NoInfo) outcomes were uncertain until the delay lapsed. Subjects preferred Info when (1) outcomes were signalled by salient auditory cues, (2) only the absence of reward was signalled, and (3) only reward was signalled, though acquisition was slower when rewards were not explicitly signalled. Our results show that a salient good news signal is not required as a conditioned reinforcer to generate paradoxical preferences. Terminal preferences support the information hypothesis but the slower acquisition of Info preference when S+ is not present is consistent with the conditioning account. We conclude that both uncertainty reduction and conditioned reinforcement influence choice.

animal behavior and cognition↗

bioRxiv2021

Imprinting on time-structured acoustic stimuli in ducklings

Filial imprinting is a dedicated learning process that lacks explicit reinforcement. The phenomenon itself is narrowly heritably canalized, but its content, the representation of the parental object, reflects the circumstances of the newborn. Imprinting has recently been shown to be even more subtle and complex than previously envisaged, since ducklings and chicks are now known to select and represent for later generalization abstract conceptual properties of the objects they perceive as neonates, including movement pattern, heterogeneity, and inter-component relationships of same or different. Here we investigate whether day-old Mallard ducklings (Anas platyrhynchos) imprint on the temporal separation between duos of brief acoustic stimuli, and whether they generalize such timing information to novel sound types. Subjects did discriminate temporal structure when imprinted and tested on natural duck calls, but not when using white noise for imprinting or testing. Our data confirm that imprinting includes the establishment of neural representations of both primary percepts and abstract properties of candidate objects, meshing together genetically transmitted prior knowledge with selected perceptual input.

animal behavior and cognition↗

bioRxiv2020

Manipulation of striatal population dynamics using temperature warps judgment of time

The basal ganglia (BG) are thought to contribute to decision-making and motor control by influencing action selection based on consequences. These functions are critically dependent on timing information that can be extracted from the evolving state of neural populations in the striatum, the major input area of the BG. However, it is debated whether striatal activity underlies latent, dynamic decision processes or kinematics of overt movement. Here, we measured the impact of temperature on striatal population activity and the behavior of rats and compared the observed effects to neural activity and behavior collected in multiple versions of a temporal categorization task. Cooler temperatures caused dilation, and warmer temperatures contraction, of both neural activity and patterns of judgment in time, mimicking endogenous decision-related variability in striatal activity. However, temperature did not similarly affect movement kinematics. These data provide compelling evidence that the time course of evolving striatal population activity dictates the speed of a latent process that is used to guide choices, but not moment by moment kinematics. More broadly, they establish temporal scaling of population activity as a likely cause and not simply a correlate of timing behavior in the brain.

neuroscience↗