scholarly journals Plastic proteans: reduced predictability in the face of predation risk in hermit crabs

2013 ◽  
Vol 9 (5) ◽  
pp. 20130592 ◽  
Author(s):  
Mark Briffa
Keyword(s):  
Individual Variation ◽  
Startle Response ◽  
Response Duration ◽  
Hermit Crabs ◽  
Residual Variance ◽  
Predation Threat ◽  
Mean Response Time ◽  
The Face ◽  
Predator Cue ◽  
Multiple Levels

Variation in behaviour occurs at multiple levels, including between individuals (personality) and between situations (plasticity). Behaviour also varies within individuals, and intra-individual variation (IIV) in behaviour describes within-individual residual variance in behaviour that remains after the effects of obvious external and internal influences on behaviour have been accounted for. IIV thus describes how predictable an individual's behaviour is. Differences in predictability, between individuals and between situations, might be biologically significant. For example, behaving unpredictably under predation threat might reduce the chance of capture. Here, we investigated the duration of startle responses in hermit crabs, in the presence and absence of a predator cue. Individuals differed in startle response duration (personality) and while individuals also varied in their sensitivity to risk, mean response time was greater in the presence of a predator (plasticity). Moreover, IIV was greater in the presence of a predator, providing some of the first evidence that the facultative injection of unpredictability into behaviour might represent a strategy for dealing with risk.

scholarly journals CO2-driven decrease in pH disrupts olfactory behaviour and increases individual variation in deep-sea hermit crabs

2015 ◽  
Vol 73 (3) ◽  
pp. 613-619 ◽  
Author(s):  
Tae Won Kim ◽  
Josi Taylor ◽  
Chris Lovera ◽  
James P. Barry
Keyword(s):  
Ocean Acidification ◽  
Individual Variation ◽  
Deep Sea ◽  
Phenotypic Diversity ◽  
Hermit Crabs ◽  
Prey Detection ◽  
Stable Conditions ◽  
Living Species ◽  
Metabolic Performance ◽  
Olfactory Behaviour

Abstract Deep-sea species are generally thought to be less tolerant of environmental variation than shallow-living species due to the relatively stable conditions in deep waters for most parameters (e.g. temperature, salinity, oxygen, and pH). To explore the potential for deep-sea hermit crabs (Pagurus tanneri) to acclimate to future ocean acidification, we compared their olfactory and metabolic performance under ambient (pH ∼7.6) and expected future (pH ∼7.1) conditions. After exposure to reduced pH waters, metabolic rates of hermit crabs increased transiently and olfactory behaviour was impaired, including antennular flicking and prey detection. Crabs exposed to low pH treatments exhibited higher individual variation for both the speed of antennular flicking and speed of prey detection, than observed in the control pH treatment, suggesting that phenotypic diversity could promote adaptation to future ocean acidification.

scholarly journals The opposite effects of routine metabolic rate and metabolic rate during startle responses on variation in the predictability of behaviour in hermit crabs

Behaviour ◽  
2016 ◽  
Vol 153 (13-14) ◽  
pp. 1545-1566 ◽  
Author(s):  
Mariana Velasque ◽  
Mark Briffa
Keyword(s):  
Metabolic Rate ◽  
Generalized Linear Models ◽  
Startle Response ◽  
Linear Models ◽  
Elevated Temperatures ◽  
Hermit Crabs ◽  
Routine Metabolic Rate ◽  
Intraindividual Variation ◽  
The Mean ◽  
Pagurus Bernhardus

Studies on animal behaviour have suggested a link between personality and energy expenditure. However, most models assume constant variation within individuals, even though individuals vary between observations. Such variation is called intraindividual variation in behaviour (IIV). We investigate if IIV in the duration of the startle response is associated with metabolic rates (MR) in the hermit crabPagurus bernhardus. We repeatedly measured startle response durations and MR during each observation. We used double hierarchical generalized linear models to ask whether among and IIV in behaviour was underpinned by MR. We found no association between the mean duration of the startle responses and either routine MR or MR during startle response. Nevertheless, we found that IIV increased with MR during startle responses and decreased with routine MR. These results indicate that crabs with higher MR during startle responses behave less predictably, and that predictability is reduced during exposure to elevated temperatures.

scholarly journals Solidarity, stance, and class identities

2018 ◽  
Vol 47 (5) ◽  
pp. 665-691 ◽  
Author(s):  
Julia Snell
Keyword(s):  
Social Class ◽  
Working Class ◽  
Market Research ◽  
Social Values ◽  
Ethnographic Study ◽  
Group Solidarity ◽  
The Face ◽  
Continued Use ◽  
Multiple Levels ◽  
Using Data

AbstractScholars have explained working-class speakers’ continued use of stigmatised vernaculars as a response to their relative powerlessness in relation to the standard language market. Research has shown how, in the face of this powerlessness, working-class communities turn to group solidarity, and use of the vernacular is seen as part of this more general orientation. As a result, two competing social values—status and solidarity—have featured prominently in discussions around language and class. I expand these discussions using data from a linguistic ethnographic study of children's language in Teesside, England. I argue that meanings related to status and solidarity operate at multiple levels and cannot be taken for granted, and demonstrate that vernacular forms thatlackstatus within the dominant sociolinguistic economy may be used toassertstatus within local interactional use. I further advance discussion of the ways local vernaculars might be intimately linked to classed subjectivities. (Social class, variation, solidarity, status, stance, indexicality, identity, interaction, ethnography)*

scholarly journals Characterization of pruriceptive trigeminothalamic tract neurons in rats

2014 ◽  
Vol 111 (8) ◽  
pp. 1574-1589 ◽  
Author(s):  
Hannah R. Moser ◽  
Glenn J. Giesler
Keyword(s):  
Discharge Rate ◽  
Response Duration ◽  
Spike Timing ◽  
Thalamic Nuclei ◽  
Medial Nucleus ◽  
The Face ◽  
Deep Layers ◽  
Noxious Stimuli

Rodent models of facial itch and pain provide a valuable tool for distinguishing between behaviors related to each sensation. In rats, pruritogens applied to the face elicit scratching using the hindlimb while algogens elicit wiping using the forelimb. We wished to determine the role of trigeminothalamic tract (VTT) neurons in carrying information regarding facial itch and pain to the forebrain. We have characterized responses to facially applied pruritogens (serotonin, BAM8–22, chloroquine, histamine, capsaicin, and cowhage) and noxious stimuli in 104 VTT neurons recorded from anesthetized rats. Each VTT neuron had a mechanically sensitive cutaneous receptive field on the ipsilateral face. All pruriceptive VTT neurons also responded to noxious mechanical and/or thermal stimulation. Over half of VTT neurons responsive to noxious stimuli also responded to at least one pruritogen. Each tested pruritogen, with the exception of cowhage, produced an increase in discharge rate in a subset of VTT neurons. The response to each pruritogen was characterized, including maximum discharge rate, response duration, and spike timing dynamics. Pruriceptive VTT neurons were recorded from throughout superficial and deep layers of the spinal trigeminal nucleus and were shown to project via antidromic mapping to the ventroposterior medial nucleus or posterior thalamic nuclei. These results indicate that pruriceptive VTT neurons are a subset of polymodal nociceptive VTT neurons and characterize a system conducive to future experiments regarding the similarities and differences between facial itch and pain.

scholarly journals The Potential of the SP System in Machine Learning and Data Analysis for Image Processing

2021 ◽  
Vol 5 (1) ◽  
pp. 7
Author(s):  
J. Gerard Wolff
Keyword(s):  
Pattern Recognition ◽  
Human Learning ◽  
Multiple Alignment ◽  
Scene Analysis ◽  
Syntactic Parsing ◽  
Information Compression ◽  
Levels Of Abstraction ◽  
Theory Of Intelligence ◽  
The Face ◽  
Multiple Levels

This paper aims to describe how pattern recognition and scene analysis may with advantage be viewed from the perspective of the SP system (meaning the SP theory of intelligence and its realisation in the SP computer model (SPCM), both described in an appendix), and the strengths and potential of the system in those areas. In keeping with evidence for the importance of information compression (IC) in human learning, perception, and cognition, IC is central in the structure and workings of the SPCM. Most of that IC is achieved via the powerful concept of SP-multiple-alignment, which is largely responsible for the AI-related versatility of the system. With examples from the SPCM, the paper describes: how syntactic parsing and pattern recognition may be achieved, with corresponding potential for visual parsing and scene analysis; how those processes are robust in the face of errors in input data; how in keeping with what people do, the SP system can “see” things in its data that are not objectively present; the system can recognise things at multiple levels of abstraction and via part-whole hierarchies, and via an integration of the two; the system also has potential for the creation of a 3D construct from pictures of a 3D object from different viewpoints, and for the recognition of 3D entities.

scholarly journals Resilience in Developmental Science: A Case for Hormesis

2019 ◽  
Author(s):  
Assaf Oshri
Keyword(s):  
Protective Factors ◽  
Dose Response ◽  
Risk And Protective Factors ◽  
Environmental Toxicity ◽  
Conceptual Frameworks ◽  
Beneficial Effects ◽  
Psychological Science ◽  
Developmental Science ◽  
The Face ◽  
Multiple Levels

Resilience refers to the ability of individuals to thrive in the face of adversity. Extant research shows that resilience is a process that emerges amidst a constellation of risk and protective factors that dynamically transact with each other at multiple levels of analyses. To date, the lion’s share of research on resilience in psychological science has shown risk and protective factors to either impede or support resilience, respectively. Some research is beginning to suggest that resilience develops in response to adversity. However, scarce conceptual frameworks exist to examine the beneficial effects of adversity on resilience. Drawing on the work of various disciplines, I propose that the study of resilience in developmental and psychological sciences can benefit from considering how biomedical disciplines identify the types and dose of adversity that strengthen or impede resilience. Specifically, I discuss how dose-response curvilinear patterns lead to an inoculation effect in the context of specific, circumscribed environmental toxicity, a process that leads to hormesis in the field of toxicology. Thus, the main goal of the paper is to propose that testing for hormesis will contribute to an empirically testable inoculation model of resilience in developmental science.

Defensive Movements Evoked by Air Puff in Monkeys

2003 ◽  
Vol 90 (5) ◽  
pp. 3317-3329 ◽  
Author(s):  
Dylan F. Cooke ◽  
Michael S. A. Graziano
Keyword(s):  
Startle Response ◽  
Receptive Fields ◽  
Initial Position ◽  
The Body ◽  
Precentral Gyrus ◽  
Cortical Areas ◽  
The Face ◽  
Ventral Intraparietal Area ◽  
Specific Reactions ◽  
Stimulation Of

Electrical stimulation of two connected cortical areas in the monkey brain, the ventral intraparietal area (VIP) in the intraparietal sulcus and the polysensory zone (PZ) in the precentral gyrus, evokes a specific set of movements. In one interpretation, these movements correspond to those typically used to defend the body from objects that are near, approaching, or touching the skin. The present study examined the movements evoked by a puff of air aimed at various locations on the face and body of fascicularis monkeys to compare them to the movements evoked by stimulation of VIP and PZ. The air-puff-evoked movements included a movement of the eyes from any initial position toward a central region and a variety of stereotyped facial, shoulder, head, and arm movements. These movements were similar to those reported on stimulation of VIP and PZ. One difference between the air-puff-evoked movements and those evoked by stimulation of VIP and PZ is that the air puff evoked an initial startle response (a bilaterally symmetric spike in muscle activity) followed by a more sustained, lateralized response, specific to the site of the air puff. In contrast, stimulation of VIP and PZ evoked mainly a sustained, lateralized response, specific to the site of the receptive fields of the stimulated neurons. We speculate that VIP and PZ may contribute to the control of defensive movements, but that they may emphasize the more spatially specific reactions that occur after startle.

scholarly journals LearningML: A Tool to Foster Computational Thinking Skills Through Practical Artificial Intelligence Projects

2020 ◽  
Vol 20 (63) ◽  
Author(s):  
Juan David Rodríguez García ◽  
Jesús Moreno-León ◽  
Marcos Román-González ◽  
Gregorio Robles
Keyword(s):  
Artificial Intelligence ◽  
Ethical Issues ◽  
Computational Thinking ◽  
Thinking Skills ◽  
Lessons Learned ◽  
Supervised Machine Learning ◽  
Hands On ◽  
The Face ◽  
Multiple Levels ◽  
Critical Citizens

El uso de sistemas de inteligencia artificial en múltiples niveles de la sociedad ofrece nuevas y prósperas oportunidades, pero también introduce nuevos riesgos y cuestiones éticas que deben abordarse. Sostenemos que la introducción de contenidos de inteligencia artificial en las escuelas a través de proyectos prácticos es el camino a seguir para educar ciudadanos conscientes y críticos, para despertar vocaciones entre los jóvenes, y para fomentar las habilidades de pensamiento computacional de los estudiantes. Sin embargo, la mayoría de las plataformas educativas de programación existentes carecen de algunas características necesarias para desarrollar proyectos completos de IA y, en consecuencia, se requieren nuevas herramientas. En este artículo presentamos LearningML, una nueva plataforma dirigida al aprendizaje automático supervisado, una de las técnicas de IA más exitosas que se encuentra en la base de casi todas las aplicaciones actuales de IA. Este trabajo describe las principales funcionalidades de la herramienta y discute algunas decisiones tomadas durante su diseño, para el que hemos tenido en cuenta las lecciones aprendidas al revisar trabajos anteriores realizados para introducir la IA en la escuela y el análisis de otras soluciones que permiten proyectos prácticos de IA. También se presentan los próximos pasos en el desarrollo de LearningML, que se centran en la validación, tanto aparente como instruccional, de la herramienta. The use of artificial intelligence systems in multiple levels of society offers new and thriving opportunities, but also introduces new risks and ethical issues that should be dealt with. We argue that the introduction of artificial intelligence contents at schools through practical, hands-on, projects is the way to go in order to educate conscientious and critical citizens, to awaken vocations among youth people, as well as to foster students’ computational thinking skills. However, most existing programming platforms for education lack some required features to develop complete AI projects and, consequently, new tools are required. In this paper we present LearningML, a new platform aimed at learning supervised Machine Learning, one of the most successful AI techniques that is in the basis of almost every current AI application. This work describes the main functionalities of the tool and discusses some decisions taken during its design, for which we took into account the lessons learned while reviewing previous works carried out for introducing AI in school and from the analysis of other solutions that enable practical AI projects. The next steps in the development of LearningML are also presented, which are focused on both the face and instructional validation of the tool.

scholarly journals Distracted decision makers: ship noise and predation risk change shell choice in hermit crabs

2019 ◽  
Vol 30 (4) ◽  
pp. 1157-1167 ◽  
Author(s):  
Svenja Tidau ◽  
Mark Briffa
Keyword(s):  
Noise Pollution ◽  
Decision Time ◽  
Information Gathering ◽  
Hermit Crabs ◽  
Anthropogenic Noise ◽  
Final Decision ◽  
Sources Of Information ◽  
Shell Size ◽  
Visual Predator ◽  
Predator Cue

Abstract Human-induced rapid environmental change such as noise pollution alters the ability of animals to integrate information cues. Many studies focus on how noise impacts single sensory channels but in reality animals rely on multimodal sources of information. In this study, we investigated the effect of anthropogenic noise and the visual presence of a predator on tactile information gathering during gastropod shell assessment in the European hermit crab Pagurus bernhardus. For hermit crabs, empty gastropod shells are a crucial resource affecting growth, reproduction, and survival. We measured shell assessment behavior and manipulated 1) the shell size (50% or 80% of the optimal), 2) sound condition (ship or ambient), and 3) visual predator cue (absence/presence). Overall we found that crabs were less likely to accept an optimal shell in the presence of ship noise, suggesting that exposure to ship noise disrupted the information gathering ability of the crabs. We also found a significant interaction between noise, predator presence, and shell size on the mean duration for the final decision to accept or reject the optimal shell. Hermit crabs in 50% shells took less time for their final decision when exposed to both ship noise and predator cue while crabs in 80% shells showed shorter decision time only when the predator cue was absent. Our results indicate that anthropogenic noise can interact with predation threat and resource quality to change resource acquisition, suggesting that noise pollution can disrupt behavior in a nonadditive way, by disrupting information use across multiple sensory channels.

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