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Results for “animal behavior and cognition”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

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At least 343 records · Page 19Linked to original sources

bioRxiv2018

Regulation of individual differences in recruitment behaviour within honey bee foraging groups

Division of labour is a hallmark of eusocial insect colonies, with different groups of workers engaged in different tasks at the same time. Foraging is a task done by older workers in honey bee colonies. Foragers use the waggle dance behaviour to inform and recruit nest mates to food sources in the environment. The recruitment process incorporates information about the food reward, the colony food stores and the environmental food availability and plays a major role in ensuring efficient exploitation of the food sources available to the colony. However, the role that individual foragers play in driving recruitment is largely unexplored. We observed the dance activity of individual foragers from the same foraging group and showed that there are consistent inter-individual differences within a foraging group leading to a division of labour in the recruitment activity. Next, we studied the effect of changing social interactions on these individual differences. Removing foragers from the group led to an increase in the dance activity of the group of remaining foragers. This was mainly driven by an increase in the dance activity of certain individuals within the foraging groups. In contrast, allowing recruits to join the foraging group had a strong negative effect on the dance activity of all the individual foragers. Our study shows that there is a fine scale division of labour in the recruitment activity within foraging groups and that this is further regulated by changing social interactions. Thus, a complex interplay between individual differences and social interactions drive recruitment activity in honey bees.

animal behavior and cognition↗

bioRxiv2018

High-magnitude innovators as keystone individuals in the evolution of culture

Borrowing from the concept of keystone species in ecological food webs, a recent focus in the field of animal behaviour has been keystone individuals: individuals whose impact on population dynamics is disproportionally larger than their frequency in the population. In populations evolving culture, such may be the role of high-magnitude innovators: individuals whose innovations are a major departure from the populations existing behavioural repertoire. Their effect on cultural evolution is twofold: they produce innovations that constitute a cultural leap, and, once copied, their innovations may induce further innovations by conspecifics (socially induced innovations), as they explore the new behaviour themselves. I use computer simulations to study the co-evolution of independent innovations, socially induced innovations, and innovation magnitude, and show that while socially induced innovation is assumed here to be less costly than independent innovation, it does not readily evolve. When it evolves, it may in some conditions select against independent innovation and lower its frequency, despite it requiring independent innovation in order to operate; at the same time, however, it leads to much faster cultural evolution. These results confirm the role of high-magnitude innovators as keystones, and suggest a novel explanation for low frequency of independent innovation.

animal behavior and cognition↗

bioRxiv2018

Conditioning nausea in a laboratory setting: A pilot study

Cancer patients can experience nausea as they approach the place where they have received chemotherapy treatment. This nausea is likely the result of Pavlovian conditioning, where the previously neutral environment acquires conditioned properties, in this case conditioned nausea, because its association with feeling ill. To investigate this phenomenon under controlled conditions, we studied the acquisition of conditioned nausea using a distinct environment paired with an emetic drug in healthy young adults. We measured two indices of conditioning: i) conditioned place aversion, and ii) conditioned drug-like (nausea) responses. Healthy volunteers (N=32) first rated their preference for two testing rooms, and then underwent four conditioning sessions in which they received either syrup of ipecac (5 ml) or placebo. A Paired Group (PG; N=17) always received ipecac in their initially preferred room and placebo in the other, while an Unpaired Group (UG; N=15) received ipecac and placebo in both rooms. Conditioned responses were assessed with i) time spent in each room, ii) room liking and preference, and iii) feelings of nausea in each room. There was no evidence of conditioned place aversion as measured by either time spent or ratings of room liking. However, the PG did report a small increase in nausea in the ipecac-paired room. Although the conditioned responses in this study were not robust, this procedure is a first step towards studying conditioned aversive drug responses in humans, which will enable development of future studies to prevent or treat anticipatory nausea.

animal behavior and cognition↗

bioRxiv2018

Controlling for temporal discounting shifts rats from geometric to human-like arithmetic bisection

How our brains measure the passage of time is still largely open for debate. One behavioral task commonly used to study how durations are perceived is the Temporal Bisection Task, in which subjects categorize time durations as either \"short\" or \"long.\" The duration equally likely to be categorized as short or long is known as the bisection point. It has been consistently demonstrated that for humans, the bisection point is near the arithmetic mean of the longest and shortest durations the subject was trained on. In contrast, for non-human subjects it has been consistently found near the geometric mean. This difference implies that humans may process or represent temporal durations differently than other species. Here we present a behavioral model that reconciles the differences by demonstrating that rats performance on this task is driven not only by their noisy estimates of duration, but also by the temporally-discounted value of future rewards. The model correctly predicts shifts in the bisection point induced by unequal rewards and explains otherwise-paradoxical psychometric reversals documented three decades ago. Furthermore, as predicted by the model, we found that modifying the Temporal Bisection Task to eliminate the temporally-discounted reward component shifted the rats bisection point from the geometric mean to the arithmetic mean, thus bringing the rat results into line with the human results. We therefore propose that humans and rats (and perhaps other non-human subjects as well) process temporal information similarly, and that the difference between them in the Temporal Bisection Task may be simply due to rats weighing temporal discounting of future rewards more strongly than humans.

animal behavior and cognition↗

bioRxiv2018

Monkey Facial Dynamics in "Minimal Interactions"

Increasingly, researchers are interested in studying the neural substrates of monkey social interactions within laboratory settings. However, semi-naturalistic monkey interactions within lab settings have not been well characterized. We here analyze \"minimal interactions\" between monkeys in the laboratory. Monkeys, like humans, produce a variety of facial expressions when they encounter one another. It has been unclear what specific information they use to guide their behavior. I recorded the facial signals of captive long-tailed macaques (Macaca fascicularis) while they visually interacted while seated in primate chairs. I found that the most consistently-evoked expressions were affiliative in character, most notably in the form of reciprocal lipsmacking. Consistent with prior experiments, lipsmacks were most evident when situational and social ambiguity was maximal: that is, in the first sessions, in the first moments of each session, and when interacting with unfamiliar individuals. Unexpectedly, head and eye orientation played dissociable roles in interactive behaviors. Most intriguingly, monkeys facial behaviors reflected both received and previously sent signals, suggesting they interpret others current signals in light of their own past communications.

animal behavior and cognition↗

bioRxiv2018

The influence of everyday events on prospective timing "in the moment"

We conducted two experiments to investigate how the eventfulness of everyday experiences influences peoples prospective timing ability. Specifically, we investigated whether events contained within movies of everyday activities serve as markers of time, as predicted by Event Segmentation Theory, or whether events pull attention away from the primary timing task, as predicted by the Attentional Gate theory. In the two experiments reported here, we asked participants to reproduce a previously learned 30 second target duration while watching a movie that contained eventful and uneventful intervals. In Experiment 2, reproduction also occurred during \"blank movies\" while watching a fixation. In both experiments, participants made shorter and more variable reproductions while simultaneously watching eventful as compared to uneventful movie intervals. Moreover, in Experiment 2, the longest reproductions were produced when participants had to watch the blank movies, which contained no events. These results support Event Segmentation Theory and demonstrate that the elapsing events during prospective temporal reproduction appear to serve as markers of temporal duration rather than distracting from the timing task.

animal behavior and cognition↗

bioRxiv2018

Do long-tailed macaques engage in intuitive statistics?

Human infants, apes and capuchins have been found to engage in intuitive statistics, generating predictions from populations to samples based on proportional information. This suggests that statistical reasoning might depend on some core knowledge that is shared with other species. Here, we investigated whether such intuitive statistical reasoning is also present in a species of Old World monkeys, to aid in the reconstruction of the evolution of this capacity. In a series of 7 test conditions, 11 long-tailed macaques were offered different pairs of populations containing varying proportions of preferred vs. neutral food items. One population always contained a higher proportion of preferred items than the other. An experimenter simultaneously drew one item out of each population, hid them in her fists and presented them to the monkey to choose. Results revealed that at least one individual seemed to make systematic population-to-sample inferences and consistently chose the sample from the population with the more favorable distribution of preferred vs. neutral food items. While it is not clear whether she used relative or absolute quantities of food, she seemed to understand the difference between a correct choice and a favorable draw and thus some basic principles of intuitive statistics.

animal behavior and cognition↗

bioRxiv2018

A systematic review and meta-analysis of Drosophila short-term-memory genetics: robust reproducibility, but little independent replication

Geneticists use olfactory conditioning in Drosophila to identify learning genes; however, little is known about how these genes are integrated into short-term memory (STM) pathways. Here, we investigated the hypothesis that the STM evidence base is weak. We performed systematic review and meta-analysis of the field. Using metrics to quantify variation between discovery articles and follow-up studies, we found that seven genes were both highly replicated, and highly reproducible. However, ~80% of STM genes have never been replicated. While only a few studies investigated interactions, the reviewed genes could account for >1000% memory. This large summed effect size could indicate irreproducibility, many shared pathways, or that current assay protocols lack the specificity needed to identify core plasticity genes. Mechanistic theories of memory will require the convergence of evidence from system, circuit, cellular, molecular, and genetic experiments; systematic data synthesis is an essential tool for integrated neuroscience.

animal behavior and cognition↗

bioRxiv2018

Correlation Detection with and without the Theory of Conditionals: A model update of Hattori & Oaksford (2007)

We view observational causal induction as a statistical independence test under rarity assumption. This paper complements the two-stage theory of causal induction proposed by Hattori and Oaksford (2007) with a computational analysis. We show that their dual-factor heuristic (DFH) model has a rational account as the square root of the index of (non-)independence under extreme rarity assumption, contrary to the criticism that the DFH model is non-normative (e.g., Lu et al., 2008). We introduce a model that considers the proportion of assumed-to-be rare instances (pARIs), which is the probability of biconditionals (according to several theories of compound conditionals) and can be seen as a simplified version of the DFH model. While being a single conditional probability, pARIs approximates the non-independence measure, the square of DFH. In reproducing the meta-analysis in Hattori and Oaksford (2007), we confirm that pARIs and DFH have the same level of descriptive adequacy, and that the two models have the highest fit among more than 40 models. Then, we critically examine the computer simulations which were central to the rational analysis in Hattori and Oaksford (2007). We point out two problems in their simluations: samples in some of the simulations being restricted to generative ones, and in-definite values of models because of the small samples. In the light of especially the latter problem of definability, pARIs shows higher applicability.

animal behavior and cognition↗

bioRxiv2018

A Hidden Markov Model to Estimate the Feeding Time of Dairy Cows Based on Indoor Positioning Data

The feeding time of dairy cows is linked with the health status of the animal and can be used to estimate daily feed intake together with other measurements. The aim of this study was to develop a model to measure the time a dairy cow spends at a feed bunk using an Ultra wide-band indoor positioning system.\n\nWe measured the feeding behavior of 50 dairy cows during 7 days using Ubisense indoor positioning system and Insentec roughage feeders. We calculated the feeding (presence at the feeder) probability of the cow using logistic regression model with the distance to feed barrier as input and used the Viterbi algorithm to calculate the most likely state (feeding or not feeding) given state transition probabilities. The model was able to predict whether the cow was at the feeding trough or not with the accuracy of 97.6%, sensitivity 95.3% and specificity 97.9%. The model was also able to estimate the mean bout duration and the number of feeding bouts.

animal behavior and cognition↗

bioRxiv2018

Reference-dependent preferences arise from structure learning

Modern theories of decision making emphasize the reference-dependency of decision making under risk. In particular, people tend to be risk-averse for outcomes greater than their reference point, and risk-seeking for outcomes less than their reference point. A key question is where reference points come from. A common assumption is that reference points correspond to expectations about outcomes, but it is unclear whether people rely on a single global expectation, or multiple local expectations. If the latter, how do people determine which expectation to apply in a particular situation? We argue that people discover reference points using a form of Bayesian structure learning, which partitions outcomes into distinct contexts, each with its own reference point corresponding to the expected outcome in that context. Consistent with this theory, we show experimentally that dramatic change in the distribution of outcomes can induce the discovery of a new reference point, with systematic effects on risk preferences. By contrast, when changes are gradual, a single reference point is continuously updated.

animal behavior and cognition↗

bioRxiv2018

The Eighty Five Percent Rule for Optimal Learning

Researchers and educators have long wrestled with the question of how best to teach their clients be they human, animal or machine. Here we focus on the role of a single variable, the difficulty of training, and examine its effect on the rate of learning. In many situations we find that there is a sweet spot in which training is neither too easy nor too hard, and where learning progresses most quickly. We derive conditions for this sweet spot for a broad class of learning algorithms in the context of binary classification tasks, in which ambiguous stimuli must be sorted into one of two classes. For all of these gradient-descent based learning algorithms we find that the optimal error rate for training is around 15.87% or, conversely, that the optimal training accuracy is about 85%. We demonstrate the efficacy of this Eighty Five Percent Rule for artificial neural networks used in AI and biologically plausible neural networks thought to describe human and animal learning.

animal behavior and cognition↗

bioRxiv2018

Social behavior and anxiety contribute to nicotine self-administration in adolescent outbred rats

Both emotional and social traits interact with genetic factors to influence smoking behavior. We previously established a socially acquired nicotine intravenous self-administration model where social learning of a nicotine-associated odor cue reversed conditioned flavor aversion and promoted nicotine intake. In this study, we first phenotyped ~ 800 adolescent heterogeneous stock rats in open field, novel object interaction, social interaction, elevated plus maze, and marble bury behaviors. These rats were then phenotyped on socially acquired nicotine self-administration. We found 243 significant correlations between different behavioral tests. Principal component regression analysis found that ~ 10-20% of the variance in nicotine-related measures, such as intake during the first or the last three fixed-ratio sessions, the progressive ratio session, and reinstatement behavior, can be explained by variations in behavioral traits. Factors corresponding to social behavior and anxiety were among the strongest predictors of nicotine intake and reinstatement of nicotine-seeking behavior. We also found many sex differences in behavioral measures. These data indicated that the genetic diversity of this population, in combination with social behavior and anxiety, are significant contributors to the divergent nicotine self-administration behavior and indicated a high probability of discovering sex-specific genetic mechanisms for nicotine intake in future genome-wide association studies.

animal behavior and cognition↗

bioRxiv2018

Liberal Detection Bias in the Unattended Periphery during Simulated Driving

While people often think they veridically perceive much of the visual surround, recent findings indicate that when asked to detect targets such as gratings embedded in visual noise, observers make more false alarms in the unattended periphery. Do these results from psychophysics studies generalize to naturalistic settings? We used a modern game engine to create a simulated driving environment where participants (as drivers) had to make judgments about the colors of pedestrians clothing in the periphery. Confirming our hypothesis based on previous psychophysics studies, we found that subjects showed liberal biases for unattended locations when detecting specific colors of pedestrians clothing. A second experiment showed that this finding was not simply due to a confirmation bias in decision-making when subjects were uncertain. Together, these results support the idea that in everyday visual experience, there is subjective inflation of experienced detail in the periphery, which may happen at the decisional level.

animal behavior and cognition↗

bioRxiv2018

Sharing is not erring: Pseudo-reciprocity in collective search

Information sharing in competitive environments may seem counterintuitive, yet it is widely observed in humans and other animals. For instance, the open-source software movement has led to new and valuable technologies being released publicly to facilitate broader collaboration and further innovation. What drives this behavior and under which conditions can it be beneficial for an individual? Using simulations in both static and dynamic environments, we show that sharing information can lead to individual benefits through the mechanisms of pseudo-reciprocity, whereby shared information leads to by-product benefits for an individual without the need for explicit reciprocation. Crucially, imitation with a certain level of innovation is required to avoid a tragedy of the commons, while the mechanism of a local visibility radius allows for the coordination of self-organizing collectives of agents. When these two mechanisms are present, we find robust evidence for the benefits of sharing--even when others do not reciprocate.

animal behavior and cognition↗

bioRxiv2018

The Tactile Receptive Fields of Freely Moving Caenorhabditis elegans Nematodes

Sensory neurons embedded in skin are responsible for the sense of touch. In humans and other mammals, touch sensation depends on thousands of diverse somatosensory neurons. By contrast, Caenorhabditis elegans nematodes have six gentle touch receptor neurons linked to simple behaviors. The classical touch assay uses an eyebrow hair to stimulate freely moving C. elegans, evoking evasive behavioral responses. While this assay has led to the discovery of genes required for touch sensation, it does not provide control over stimulus strength or position. Here, we present an integrated system for performing automated, quantitative touch assays that circumvents these limitations and incorporates automated measurements of behavioral responses. Highly Automated Worm Kicker (HAWK) unites microfabricated silicon force sensors and video analysis with real-time force and position control. Using this system, we stimulated animals along the anterior-posterior axis and compared responses in wild-type and spc-1(dn) transgenic animals, which have a touch defect due to expression of a dominant-negative spectrin protein fragment. As expected from prior studies, delivering large stimuli anterior to the mid-point of the body evoked a reversal, but such a stimulus applied posterior to the mid-point evoked a speed-up. The probability of evoking a response of either kind depended on stimulus strength and location; once initiated, the magnitude and quality of both reversal and speed-up behavioral responses were uncorrelated with stimulus location, strength, or the absence or presence of the spc-1(dn) transgene. Wild-type animals failed to respond when the stimulus was applied near the mid-point. These results establish that stimulus strength and location govern the activation of a stereotyped motor program and that the C. elegans body surface consists of two receptive fields separated by a gap.

animal behavior and cognition↗

bioRxiv2018

Individual- and population-level drivers of consistent foraging success across environments

Individual foraging is under strong natural selection. Yet, whether individuals differ consistently in their foraging success across environments, and which individual and population-level traits might drive such differences, is largely unknown. We addressed this question in a field experiment, conducting over 1,100 foraging trials with nine subpopulations of guppies, Poecilia reticulata, translocating them across environments in the wild. A-priori, we determined the individual social phenotypes. We show that individuals consistently differed in reaching food, but not control, patches across environments. Social individuals reached more food patches than less social ones and males reached more food patches than females. Overall, individuals were, however, more likely to join females at patches than males, which explains why individuals in subpopulations with relatively more females reached, on average, more food patches. Our results provide rare evidence for individual differences in foraging success across environments, driven by individual and population level (sex ratio) traits.

animal behavior and cognition↗

bioRxiv2018

Active Function Learning

How do people actively explore to learn about functional relationships, that is, how continuous inputs map onto continuous outputs? We introduce a novel paradigm to investigate information search in continuous, multi-feature function learning scenarios. Participants either actively selected or passively observed information to learn about an underlying linear function. We develop and compare different variants of rule-based (linear regression) and non-parametric (Gaussian process regression) active learning approaches to model participants active learning behavior. Our results show that participants performance is best described by a rule-based model that attempts to efficiently learn linear functions with a focus on high and uncertain outcomes. These results advance our understanding of how people actively search for information to learn about functional relations in the environment.

animal behavior and cognition↗