Looking out for danger: Theoretical and empirical issues in translating human attention bias tasks to assess animal affective states.

Understanding animal emotional (affective) state is highly relevant to various disciplines (e.g., animal welfare, neuroscience, comparative psychology), and has been significantly advanced by translating affect-induced cognitive bias paradigms rooted in human psychology to non-human animal studies.

Exploring the similarities between risk factors triggering depression in humans and elevated in-cage "inactive but awake" behavior in laboratory mice.

Introduction: Depression is a human mental disorder that can also be inferred in non-human animals. This study explored whether time spent inactive but awake ("IBA") in the home-cage in mice was further triggered by risk factors similar to those increasing vulnerability to depression in humans (early life stress, genetic predispositions, adulthood stress).

Methods: Eighteen DBA/2 J and 18 C57BL/6 J females were tested, of which half underwent as pups a daily maternal separation on post-natal days 2-14 (early-life stress "ELS") (other half left undisturbed).

Validation of complementary non-invasive tools for stress assessment in spotted paca ().

Monitoring the concentration of glucocorticoid metabolites (GCMs) in faecal samples is a non-invasive tool for physiological stress evaluation, particularly useful when studying wild species. However, both negative and positive stimuli (distress and eustress, respectively) can lead to a rise in glucocorticoids. Thus, besides validating whether GCM concentration in faeces reflects endogenous adrenal activity, we also need to identify behavioural indicators of distress to avoid misinterpretation.

Do you see what I see? Testing horses' ability to recognise real-life objects from 2D computer projections.

The use of 2-dimensional representations (e.g. photographs or digital images) of real-life physical objects has been an important tool in studies of animal cognition.

Responses to environmental enrichment are associated with personality characteristics in chestnut-bellied seed finches (Sporophila angolensis).

Environmental enrichment (EE) is used to promote natural behaviours in captive animals and may hold promise as a form of pre-release training, a strategy for improving coping skills of translocated birds. We investigated the use of EE to enhance foraging and vigilance behaviours of captive Sporophila angolensis, which may be related to post-release survival. We also evaluated whether consistent individual behavioural differences affected birds' responses to EE.

Do greater levels of in-cage waking inactivity in laboratory mice reflect a spontaneous depression-like symptom? A pharmacological investigation.

We previously identified in laboratory mice an inactive state [being awake with eyes open motionless within the home cage; inactive but awake, 'IBA'] sharing etiological factors and symptoms with human clinical depression. We further test the hypothesis that greater time spent displaying IBA indicates a depression-like state in mice by investigating whether the antidepressant Venlafaxine, environmental enrichment, and their combination, alleviate IBA. Seventy-two C57BL/6J and 72 DBA/2J female mice were pseudo-randomly housed post-weaning in mixed strain-pairs in non-enriched (NE; 48 pairs) or in environmentally enriched (EE; 24 pairs) cages.

Learning from lockdown - Assessing the positive and negative experiences, and coping strategies of researchers during the COVID-19 pandemic.

With the disruption of nonessential research due to the COVID-19 pandemic, researchers faced unexpected changes in their work and personal life. We assessed what challenges researchers encountered during lockdown and whether gender, career level, discipline, and job-permanency influenced their experiences (negative and positive), thereby collecting empirical material which could provide valuable information for future mentoring/supporting practices. Data were collected between July-August 2020 an online-survey, and answers from 210 respondents (78% female, 21% male, 1% non-disclosed gender) working in Animal Behaviour and Welfare (ABW, 57%), other biological sciences (37%) or social sciences (6%) were analysed.

Measuring affect-related cognitive bias: Do mice in opposite affective states react differently to negative and positive stimuli?

Affect-driven cognitive biases can be used as an indicator of affective (emotional) state. Since humans in negative affective states demonstrate greater responses to negatively-valenced stimuli, we investigated putative affect-related bias in mice by monitoring their response to unexpected, task-irrelevant stimuli of different valence. Thirty-one C57BL/6J and 31 DBA/2J females were individually trained to return to their home-cage in a runway.

Could Greater Time Spent Displaying Waking Inactivity in the Home Environment Be a Marker for a Depression-Like State in the Domestic Dog?

Dogs exposed to aversive events can become inactive and unresponsive and are commonly referred to as being "depressed", but this association remains to be tested. We investigated whether shelter dogs spending greater time inactive "awake but motionless" (ABM) in their home-pen show anhedonia (the core reduction of pleasure reported in depression), as tested by reduced interest in, and consumption of, palatable food (Kong test). We also explored whether dogs being qualitatively perceived by experts as disinterested in the food would spend greater time ABM (experts blind to actual inactivity levels).

Investigating determinants of yawning in the domestic (Equus caballus) and Przewalski (Equus ferus przewalskii) horses.

Yawning is rare in herbivores which therefore may be an interesting group to disentangle the potential function(s) of yawning behaviour. Horses provide the opportunity to compare not only animals living in different conditions but also wild versus domestic species. Here, we tested three hypotheses by observing both domestic and Przewalski horses living in semi-natural conditions: (i) that domestic horses may show an elevated rate of yawning as a result of the domestication process (or as a result of life conditions), (ii) that individuals experiencing a higher level of social stress would yawn more than individuals with lower social stress and (iii) that males would yawn more often than females.

Stereotypic behaviour in standard non-enriched cages is an alternative to depression-like responses in C57BL/6 mice.

Depressive-like forms of waking inactivity have been recently observed in laboratory primates and horses. We tested the hypotheses that being awake but motionless within the home-cage is a depression-like symptom in mice, and that in impoverished housing, it represents an alternative response to stereotypic behaviour. We raised C57BL/6 ('C57') and DBA/2 ('DBA') females to adulthood in non-enriched (n=62 mice) or enriched (n=60 mice) cages, observing home-cage behaviour during the active (dark) phases.

Mixed-strain housing for female C57BL/6, DBA/2, and BALB/c mice: validating a split-plot design that promotes refinement and reduction.

Background: Inefficient experimental designs are common in animal-based biomedical research, wasting resources and potentially leading to unreplicable results. Here we illustrate the intrinsic statistical power of split-plot designs, wherein three or more sub-units (e.g.

Cage-induced stereotypic behaviour in laboratory mice covaries with nucleus accumbens FosB/ΔFosB expression.

Stereotypic behaviour (SB) occurs in certain human disorders (e.g. autism), and animals treated with stimulants or raised in impoverished conditions, including laboratory mice in standard cages.

Co-housing rodents with different coat colours as a simple, non-invasive means of individual identification: validating mixed-strain housing for C57BL/6 and DBA/2 mice.

Standard practice typically requires the marking of laboratory mice so that they can be individually identified. However, many of the common methods compromise the welfare of the individuals being marked (as well as requiring time, effort, and/or resources on the part of researchers and technicians). Mixing strains of different colour within a cage would allow them to be readily visually identifiable, negating the need for more invasive marking techniques.

Comparison of clinical examinations of back disorders and humans' evaluation of back pain in riding school horses.

Background: Questionnaires are a common tool to assess people's opinion on a large scale or to sound them out about their subjective views. The caretakers' opinion about animals' "personality" has been used in many studies. The aim of the present study was to assess whether the owners' subjective evaluation was effective to detect back disorders.

Plasma cortisol and faecal cortisol metabolites concentrations in stereotypic and non-stereotypic horses: do stereotypic horses cope better with poor environmental conditions?

Background: Stereotypic behaviours, i.e. repetitive behaviours induced by frustration, repeated attempts to cope and/or brain dysfunction, are intriguing as they occur in a variety of domestic and captive species without any clear adaptive function.

Towards a postural indicator of back pain in horses (Equus caballus).

Postures have long been used and proved useful to describe animals' behaviours and emotional states, but remains difficult to assess objectively in field conditions. A recent study performed on horses using geometric morphometrics revealed important postural differences between 2 horse populations differing in management conditions (leisure horses living in social groups used for occasional "relaxed" riding/riding school horses living in individual boxes used in daily riding lessons with more constraining techniques). It was suggested that these postural differences may reflect chronic effects of riding techniques on the horses' kinematics and muscular development.

Towards an ethological animal model of depression? A study on horses.

Background: Recent reviews question current animal models of depression and emphasise the need for ethological models of mood disorders based on animals living under natural conditions. Domestic horses encounter chronic stress, including potential stress at work, which can induce behavioural disorders (e.g.

On the significance of adult play: what does social play tell us about adult horse welfare?

Play remains a mystery and adult play even more so. More typical of young stages in healthy individuals, it occurs rarely at adult stages but then more often in captive/domestic animals, which can imply spatial, social and/or feeding deprivations or restrictions that are challenging to welfare, than in animals living in natural conditions. Here, we tested the hypothesis that adult play may reflect altered welfare states and chronic stress in horses, in which, as in several species, play rarely occurs at adult stages in natural conditions.

Geometric morphometrics as a tool for improving the comparative study of behavioural postures.

Describing postures has always been a central concern when studying behaviour. However, attempts to compare postures objectively at phylogenetical, populational, inter- or intra-individual levels generally either rely upon a few key elements or remain highly subjective. Here, we propose a novel approach, based on well-established geometric morphometrics, to describe and to analyse postures globally (i.

Partners with bad temper: reject or cure? A study of chronic pain and aggression in horses.

Background: Experiencing acute pain can affect the social behaviour of both humans and animals and can increase the risk that they exhibit aggressive or violent behaviour. However, studies have focused mainly on the impact of acute rather than chronic painful experiences. As recent results suggest that chronic pain or chronic discomfort could increase aggressiveness in humans and other mammals, we tested here the hypothesis that, in horses, aggression towards humans (a common source of accidents for professionals) could be linked to regularly reported vertebral problems of riding horses.

Reinforcement as a mediator of the perception of humans by horses (Equus caballus).

A central question in the interspecific human/animal relationship is how domestic animals perceive humans as a significant element of their environment. In this study, we tested the hypothesis that the use of positive or negative reinforcement in horse training may have consequences on the animals' perception of humans, as a positive, negative or neutral element. Two groups of ponies were trained to walk backwards in response to a vocal order using either positive or negative reinforcement.

Human direct actions may alter animal welfare, a study on horses (Equus caballus).

Background: Back pain is the cause of bad welfare in humans and animals. Although vertebral problems are regularly reported on riding horses, these problems are not always identified nor noticed enough to prevent these horses to be used for work.

Methodology/principal Findings: Nineteen horses from two riding centres were submitted to chiropractic examinations performed by an experienced chiropractor and both horses' and riders' postures were observed during a riding lesson.

A preliminary study of the effects of handling type on horses' emotional reactivity and the human-horse relationship.

Handling is a crucial component of the human-horse relationship. Here, we report data from an experiment conducted to assess and compare the effect of two training methods. Two groups of six Welsh mares were trained during four sessions of 50 min, one handled with traditional exercises (halter leading, grooming/brushing, lifting feet, lunging and pseudo-saddling (using only girth and saddle pad) and the second group with natural horsemanship exercises (desensitization, yielding to body pressure, lunging and free-lunging).

How horses (Equus caballus) see the world: humans as significant "objects".

This study aimed to determine whether horses have a kind of memory of humans (based on previous interactions), leading to a general significance of humans revealed by their reactions to humans in subsequent interactions. Subjects were 59 adult horses used to interact daily with humans. Three types of behavioural tests involving an unknown experimenter evaluated three possibly different memorized types of human-animal interactions (not work-related, using work-related objects, unfamiliar working task).