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Measuring emotional processes in animals: The utility of a cognitive approach
Abstract
Contemporary researchers regard emotional states as multifaceted, comprising physiological, behavioural, cognitive and subjective components. Subjective, conscious experience of emotion can be inferred from linguistic report in humans, but is inaccessible to direct measurement in non-human animals. However, measurement of other components of emotion is possible, and a variety of methods exist for monitoring emotional processes in animals by measuring behavioural and physiological changes. These are important tools, but they have limitations including difficulties of interpretation and the likelihood that many may be sensitive indicators of emotional arousal but not valence-pleasantness/unpleasantness. Cognitive components of emotion are a largely unexplored source of information about animal emotions, despite the fact that cognition-emotion links have been extensively researched in human cognitive science indicating that cognitive processes-appraisals of stimuli, events and situations-play an important role in the generation of emotional states, and that emotional states influence cognitive functioning by inducing attentional, memory and judgement biases. Building on this research, it is possible to design non-linguistic cognitive measures of animal emotion that may be especially informative in offering new methods for assessing emotional valence (positive as well as negative), discriminating same-valenced emotion of different types, identifying phenotypes with a cognitive predisposition to develop affective disorders, and perhaps shedding light on the issue of conscious emotional experiences in animals.
... Consequently, scientists in these fields are looking for various indicators of emotional states such as behavioral and physiological changes that accompany such states in order to assess in which emotional state an animal is, or whether or not animals of the considered species experience them at all (Kremer et al. 2020). For example, the state of fear may be accompanied by behavior like freezing, fleeing, or even attacking, and by physiological changes such as increased heart rate, increased blood pressure, and enhanced levels of circulating glucocorticoids (Mendl et al. 2009 (Proctor et al. 2013) and the methods for assessing positive states are limited (Paul et al. 2005). This limits the research of emotions, particularly from the perspective of animal welfare science, which aims at finding ways to induce positive states, in addition to reducing pain and suffering in animals (Boissy et al. 2007). ...
... An increasingly used indicator of emotional states in non-human animals is cognitive bias (Paul et al. 2005). This indicator has its background in psychological experiments on humans. ...
... 56 Their judgment was biased. The authors suggested using behavioral responses in ambiguous situations as an indicator of emotional states (Harding et al. 2004;Paul et al. 2005), which initiated numerous studies that demonstrated that cognitive judgment bias can be found in a wide range of taxa, from pigs to bumblebees (reviewed in Lagisz et al. 2020;Mendl et al. 2009;Neville et al. 2020). Since both pharmacological and environmental manipulations of affective states alter judgment bias (reviewed in Lagisz et al. 2020;Neville et al. 2020), cognitive judgment bias tests can be considered a promising tool for assessing emotional states of non-human animals. ...
This book comprises various areas in the philosophy of science. It begins with a general consideration of philosophical methodology and its significance for the philosophy of science. Applying the methodological framework developed in the first part, it continues to work on some conceptual issues within the philosophy of biology, namely issues concerning the notions of biological fitness and functions. Subsequently, it ends with a case study of the applied philosophy of science suggesting new experiments based on theoretical considerations.
... Such states may be categorised as discrete emotions which humans label with words such as 'fear', 'anger', 'happiness, 'joy'. They can also be distinguished according to key underlying dimensions; particularly prominent is the 'core affect' model that identifies valence (i.e., pleasant/ unpleasantness) and activation or arousal as the two major dimensions Paul et al., 2005;Russell, 2003). In humans, most affective states have a conscious component (they feel like something but see e.g., Winkielman and Berridge 2004 for a discussion of unconscious emotions) and this is also likely to be the case in many non-human animals (hereafter animals), although which species is still debated (e.g., Birch et al., 2020;Dung and Newen, 2023;Paul et al., 2005Paul et al., , 2020. ...
... They can also be distinguished according to key underlying dimensions; particularly prominent is the 'core affect' model that identifies valence (i.e., pleasant/ unpleasantness) and activation or arousal as the two major dimensions Paul et al., 2005;Russell, 2003). In humans, most affective states have a conscious component (they feel like something but see e.g., Winkielman and Berridge 2004 for a discussion of unconscious emotions) and this is also likely to be the case in many non-human animals (hereafter animals), although which species is still debated (e.g., Birch et al., 2020;Dung and Newen, 2023;Paul et al., 2005Paul et al., , 2020. The challenges of translating the quintessentially subjective concept of human emotion to allow scientific studies of affective states in other species are discussed by Mendl et al., (2022). ...
... Even with uncertainty about which species consciously experience affective states and what their experiences are like, changes in physiology, behaviour and cognition associated with affect have been described similarly in humans and animals (Paul et al., 2005). Behavioural and physiological changes can be assessed quantitatively, but the acquisition, interpretation and understanding of shifts in these indices concerning animal affect are not always straightforward (Mason and Mendl, 1993;Mendl et al., 2009;Paul et al., 2005). ...
... Measuring changes in cognitive processing (e.g., biases in attention, memory, and decision-making) is an important approach to studying non-human animal emotions (Mendl et al., 2009;Paul et al., 2005), since affective valence (i.e., pleasant or unpleasantness of the emotional state) can be inferred from the direction of cognitive biases (Mendl et al., 2010;Paul et al., 2005). In humans, negative affect is associated with a greater expectation of negative outcomes under ambiguity (i.e., 'pessimism'), heightened attention allocation toward negative information, and greater likelihood of negative memory recall (reviewed in e.g., Blanchette and Richards, 2010;Paul et al., 2005). ...
... Measuring changes in cognitive processing (e.g., biases in attention, memory, and decision-making) is an important approach to studying non-human animal emotions (Mendl et al., 2009;Paul et al., 2005), since affective valence (i.e., pleasant or unpleasantness of the emotional state) can be inferred from the direction of cognitive biases (Mendl et al., 2010;Paul et al., 2005). In humans, negative affect is associated with a greater expectation of negative outcomes under ambiguity (i.e., 'pessimism'), heightened attention allocation toward negative information, and greater likelihood of negative memory recall (reviewed in e.g., Blanchette and Richards, 2010;Paul et al., 2005). ...
... Measuring changes in cognitive processing (e.g., biases in attention, memory, and decision-making) is an important approach to studying non-human animal emotions (Mendl et al., 2009;Paul et al., 2005), since affective valence (i.e., pleasant or unpleasantness of the emotional state) can be inferred from the direction of cognitive biases (Mendl et al., 2010;Paul et al., 2005). In humans, negative affect is associated with a greater expectation of negative outcomes under ambiguity (i.e., 'pessimism'), heightened attention allocation toward negative information, and greater likelihood of negative memory recall (reviewed in e.g., Blanchette and Richards, 2010;Paul et al., 2005). That underlying negative mood (i.e., longer-lasting states arisen from the accumulation of short-lasting emotions in response to specific stimuli) induces pessimistic judgement also in animals has been demonstrated in various mammal, bird, and insect species (reviewed in e.g., Gygax, 2014;Lagisz et al., 2020). ...
... Judgement bias tests -i.e., interpretation bias testing in humans and cognitive judgement bias (CJB) testing in animals -reflect affective state through assessment of the subject's interpretation of ambiguous stimuli 14 . In general, when faced with ambiguous stimuli or situations, those in positive affective states are more likely to make optimistic judgements, whereas those in negative affective states are more likely to make pessimistic judgements 15 . For example, someone being told that their artwork looks 'interesting' could interpret this positively (as a compliment) or negatively (as an insult) depending on their affective state. ...
... To expand upon research using human subjects, work has been done to adapt these tasks for use in animals using CJB tasks 16 . Unlike previously employed physiological and behavioural measurements, CJB tests allow the objective assessment of both negative and positive affect 15,17 . Additionally, CJB distinguishes between emotion and arousal, whereas physiological measures such as corticosterone levels may not; for example, distinguishing between arousal from excitement or arousal from fear 18,19 . ...
Cognitive judgement bias (CJB) refers to the interpretation of ambiguous stimuli in a negative (pessimistic) or positive (optimistic) way. Negative CJB is observed in depression and anxiety, conditions that burden affected individuals and their caregivers. Pre-clinical animal research is key to understanding CJB and developing therapies for affective and anxiety disorders, so a translationally relevant CJB test would be a useful addition to the existing pre-clinical rodent touchscreen test battery. Here, a CJB task in mouse touchscreen operant chambers was adapted and validated using pharmacological agents, bupropion and tetrabenazine, known to induce positive and negative CJB, respectively. Further, negative shifts in CJB were observed following an injection procedure (handling and intraperitoneal injection with a saline solution), demonstrating the sensitivity of the task. Interestingly, whereas social isolation has been linked to changes in affective state in humans, 8 weeks of single-housing in mice did not alter CJB but did induce anxiety-like behaviour in an open field. Collectively, these results present a validated task to assess CJB in mice, which will facilitate future explorations into the underlying neurobiology and potential treatment of affective and anxiety disorders.
... Paul et al. (2020), p. 750), for instance, argue that emotions are "state[s] characterized by loosely coordinated changes in the following five components: (i) feeling---changes in subjective experience, (ii) cognition--changes in attentional, perceptual, and inferential processes (appraisals), (iii) action--changes in the predisposition for or execution of specific responses, (iv) expression--changes in facial, vocal, postural appearance, and (v) physiology--changes in physiological and neural activity." While there are disagreements about the roles of each component, this view has paved the way for much recent research on animal emotions (e. g., Paul et al., 2005;Mendl et al., 2010;Anderson and Adolphs, 2014;De Vere and Kuczaj, 2016;Adolphs, 2017;Crump et al., 2020;Kremer et al., 2020;a.m.o.). ...
... To address these challenges, researchers propose to measure various indicators simultaneously, hoping that a composite picture will emerge (e.g., Dawkins, 1980;Broom and Johnson, 1993;Richter et al., 2018). For example, an animal's negative state would be inferred from its correlated physiological (e.g., high cortisol levels) and behavioral reactions (e.g., flee-freeze-fight responses) to stimuli likely perceived as threatening (Paul et al., 2005). However, a remaining problem is that the components of emotions-and their interaction during emotional episodes-are not well understood from the outset. ...
This paper introduces a mechanistic framework for understanding animal emotions, which is designed for biologists studying animal behavior and welfare. Researchers often examine emotions—short-term valenced experiences—through behavioral, somatic, and cognitive indicators. However, proposed indicators are often ambivalent (emerge in contexts with opposing emotional valence) or undetermined (arise in both affective and non-affective processes). To ground hypothesis formulation regarding animal emotions on a better foundation, the paper advocates for building on what we know regarding the mechanisms of human emotions—the behavioral rules that transform sensory input into motor output during emotional episodes. In particular, it integrates key assumptions from three dominant psychological theories of emotion—innate, appraisal, and network theories—into a single framework and argues that this can serve as a common ground to transfer insights from human to animal emotion research. Additionally, the paper tackles the question of how emotions relate to closely linked processes such as decision-making, distinguishing between parallel architecture models—where emotions and decision-making processes interact but remain distinct—and unified models—where affective states are conceived as integral to goal-oriented processes. Finally, we discuss how our mechanistic proposal can help us address four key questions in animal emotion research: Do animals experience emotions? If so, which animals experience emotions? Which emotions do they experience? And how do these emotions compare to human emotions? The paper concludes by emphasizing the need for further empirical research on the mechanisms of animal emotions and their distinction from other processes.
... The fundamental understanding of the relationship between emotions and cognitive processes is supported by research (Paul et al., 2005), which emphasizes the multicomponent nature of emotions, including physiological, behavioural, cognitive, and subjective elements. Their work demonstrates that cognitive processes play a key role in generating emotional states, while emotional states influence cognitive functioning, causing biases in attention, memory, and judgment. ...
... The development of the platform model is based on contemporary understanding of the relationship between cognitive and emotional processes. According to Paul et al. (2005), emotional states significantly modify cognitive processes such as attention and memory, which provides important advantages in the learning process. The platform model considers these relationships through: ...
Modern education requires innovative approaches that consider both cognitive and emotional aspects of learning. This paper presents the concept of an adaptive educational platform that utilizes artificial intelligence technologies for analysing students’ emotional states and integrating an emotional approach into the educational process. The platform is based on advanced machine learning methods, including convolutional and recurrent neural networks, as well as ensemble learning algorithms. Special attention is paid to data protection and ethics, emphasizing developers’ responsibility to all participants in the educational process. The author concluded that for further development it is necessary to strengthen interdisciplinary collaboration between artificial intelligence experts and educational researchers, enhance educators’ competencies in artificial intelligence and educational technologies, and develop ethical standards governing data use. The implementation of the described technological and methodological solutions will enable the development of a functional educational platform prototype and conduct comprehensive most effective use of digital tools and platforms.
... How animals perceive their world is a crucial and ethically relevant question because their perception of environmental stimuli can be either more or less positive or negative. Perception can depend on the valence of an individual's underlying mood, i.e., long-lasting affective state arising from the accumulation and integration of short-lasting emotions in response to specific stimuli [2,3]. Positive mood depends on internal physiological balance, a satisfaction of behavioural needs, an absence of negative emotions, and the presence of positive emotions [4]. ...
... Positive mood depends on internal physiological balance, a satisfaction of behavioural needs, an absence of negative emotions, and the presence of positive emotions [4]. In humans, negative mood is associated with cognitive biases such as negative judgement bias (a greater expectation of negative outcomes under ambiguity, i.e., 'pessimism') and attention and memory negative bias [3]. ...
Animal-assisted interventions (AAIs) have become increasingly popular, with horses being one of the most commonly used species. While the effects of equine-assisted interventions (EAIs) have been widely studied in humans, research focusing on animals involved in such work is limited. Understanding how animals perceive their world is ethically important because their perception reflects the valence of their underlying mood. We investigated the cognitive judgement bias (pessimistic vs. optimistic) and perception of humans (negative vs. positive) in horses from three different facilities, divided into two groups: horses involved only in riding school lessons (RS, N = 14) and horses participating in both riding school and EAI lessons (EAI-RS, N = 16). We hypothesised that horses engaged in both types of work would be more negatively impacted than RS horses because the two activities may be demanding. No significant effects of work on pessimistic bias and negative perception of humans were found. However, a modulating effect was found in the interaction between work type and facility management. These findings highlight the impact of both the type of work and facility management on the cognition and underlying affective states of EAI-RS horses.
... It has long been recognized in human psychology that cognitive processes both influence and are influenced by emotional states. Researchers have sought parallels between humans and animals in their studies of emotion and cognition [7][8][9][10], which could allow for the identification of objective measures of cognitive performance as indicators of emotional state. For example, studies on humans have shown that emotional states influence cognitive processes such as attention, memory, and judgment [9]. ...
... Researchers have sought parallels between humans and animals in their studies of emotion and cognition [7][8][9][10], which could allow for the identification of objective measures of cognitive performance as indicators of emotional state. For example, studies on humans have shown that emotional states influence cognitive processes such as attention, memory, and judgment [9]. ...
Objective: In recent years, the use of zebrafish (Danio rerio) as laboratory models has significantly increased. Ensuring their welfare is crucial, with the cognitive bias test emerging as a valuable tool to assess their emotional state. This systematic review examines the application of the cognitive bias test in zebrafish research. Data: The review adhered to PRISMA guidelines. Sources: A systematic search was conducted in scientific databases, including PubMed and Scopus, yielding 30 articles. Additionally, one abstract identified through bibliographic screening of selected papers was included. Study Selection: Six studies were selected for analysis, and their quality was assessed using SYRCLE's risk-of-bias tool. Results: Three experimental models were employed to conduct the cognitive bias test in zebrafish, focusing on the relationship between their affective state and environmental conditions, cognitive abilities, and life-history strategies but none of the studies adequately reported the techniques employed to reduce bias. Discussion: The cognitive bias test proved effective in assessing the emotional state of zebrafish; however, methodological biases may have influenced the results. Conclusion: The cognitive bias test offers valuable insights into how emotional states affect cognitive abilities, responses to environmental changes (e.g., physical enrichment), and stress responses. Further research addressing methodological limitations is necessary to validate these findings and improve data reproducibility.
... It has long been recognized in human psychology that cognitive processes both influence and are influenced by emotional states. Researchers have sought parallels between humans and animals in their studies of emotion and cognition [7][8][9][10], which could allow for the identification of objective measures of cognitive performance as indicators of emotional state. For example, studies on humans have shown that emotional states influence cognitive processes such as attention, memory, and judgment [9]. ...
... Researchers have sought parallels between humans and animals in their studies of emotion and cognition [7][8][9][10], which could allow for the identification of objective measures of cognitive performance as indicators of emotional state. For example, studies on humans have shown that emotional states influence cognitive processes such as attention, memory, and judgment [9]. ...
Objective: In recent years, the use of zebrafish (Danio rerio) as laboratory models has significantly increased. Ensuring their welfare is crucial, with the cognitive bias test emerging as a valuable tool to assess their emotional state. This systematic review examines the application of the cognitive bias test in zebrafish research. Data: The review adhered to PRISMA guidelines. Sources: A systematic search was conducted in scientific databases, including PubMed and Scopus, yielding 30 articles. Additionally, one abstract identified through bibliographic screening of selected papers was included. Study Selection: Six studies were selected for analysis, and their quality was assessed using SYRCLE’s risk-of-bias tool. Results: Three experimental models were employed to conduct the cognitive bias test in zebrafish, focusing on the relationship between their affective state and environmental conditions, cognitive abilities, and life-history strategies but none of the studies adequately reported the techniques employed to reduce bias. Discussion: The cognitive bias test proved effective in assessing the emotional state of zebrafish; however, methodological biases may have influenced the results. Conclusion: The cognitive bias test offers valuable insights into how emotional states affect cognitive abilities, responses to environmental changes (e.g., physical enrichment), and stress responses. Further research addressing methodological limitations is necessary to validate these findings and improve data reproducibility.
... The theory behind cognitive bias tests stems from human psychology and has been validated for use in multiple species [22,[37][38][39][40][41][42][43][44][45][46]. Generally, those with more pessimistic affects will judge an ambiguous stimulus with fear or anxiety, while those with more optimistic affects will judge the same ambiguous stimulus in a more relaxed, exploratory way [47,48]. Novelty tests, where an animal's response to an unfamiliar object or environment is observed [49][50][51][52], are a common form of cognitive bias testing. ...
... Studies of other species have similarly found that increasing environmental complexity alters behavioral and neural responses during these tests [19,22,27,53,55,81]. The findings here suggest that following the Complex housing condition, tarantula behavior was more neophilic and exploratory, which in other contexts have been described as more optimistic emotional states [27,47,48,55]. Other studies have similarly identified increased neophilia in other arachnid species following time spent in a complex living environment compared to a simpler environment [32, 56,57], including a study of tarantulas in the same Theraphosidae family. ...
Increased environmental complexity has positive effects on the welfare status of vertebrates living in human care; however, this line of research has received little focus in invertebrates. Here we conducted a preliminary investigation of Brazilian black tarantula (Grammastola pulchra) behavior in relation to environmental complexity. Using a counterbalanced design, we housed tarantulas in both Standard and Complex environments. Complex housing was differentiated from Standard by being approximately six times larger and containing six times as many structural elements. We evaluated (1) how does tarantula behavior differ between these two housing conditions, (2) does housing affect tarantula behavior in a novel environment test, and (3) do tarantulas prefer one housing condition over the other? Activity budgets were approximately equivalent between the two housing conditions with inactivity accounting for nearly all observed behavior. Home ranges and core areas were 77% and 113% larger in the Complex housing condition. When in a novel environment, tarantulas had 150% greater odds of being active after living in the Complex condition. Interestingly, the tarantulas showed no clear preference for either environment in the preference test. Our preliminary results suggest tarantula welfare may be improved with greater environmental complexity as demonstrated through more neophilic response to novelty and greater home range and core area size when living in Complex housing. However, it is worth noting that broad patterns of behavior were similar, no clear preference in housing was identified, and our study sample size was limited. Further research is needed to better understand the behavior and welfare of tarantulas, but this study demonstrates how established methodologies used in the study of vertebrates can be readily applied to invertebrates.
... Attention bias is a type of cognitive bias testing: whole-animal measures that estimate the overall welfare of an animal through the effects of welfare on cognitive processes such as judgment, attention, and memory (Paul et al. 2005). Although judgment bias tests (examining the level of optimism or pessimism an animal displays as an indicator of welfare status; Mendl et al. 2009) are most commonly used in animal welfare science, the extensive preparation and animal training required means they are not well-suited to measuring wild animal welfare. ...
... Attention bias tests examine the attention an animal pays to negative and positive stimuli within its environment (e.g., gaze frequency and duration), which is taken to be related to their overall welfare level (similar to humans experiencing negative affect paying more attention to threatening stimuli; Crump et al., 2018;Paul et al., 2005). In contrast to judgment bias, attention bias tests require little set-up (i.e., the presentation of salient cues and the equipment to measure the duration of gaze or another relevant sensory modality) and therefore appear more promising for the wild context. ...
... Tools to assess animals' affective states are important for animal welfare research. The cognitive bias task has revolutionised this aspect of animal welfare research by providing a validated method to assess the valence (positive or negative) of emotional states in many animal species (Harding et al. 2004;Paul et al. 2005;Mendl et al. 2009Mendl et al. , 2010a, rather than focusing solely on arousal levels, as is often the case with other commonly used measures of animal welfare such as heart rate or glucocorticoid levels. Generally, in a cognitive bias task, animals are trained to discriminate between two stimuli, one associated with a reward and the other associated with the absence of a reward. ...
Successive negative contrast (SNC) is a decrease in response when animals unexpectedly face reward devaluation to levels below those of animals always receiving low-value rewards. SNC appears to be influenced by background affective states and has thus been proposed as a tool for assessing animal welfare. While reported in several mammal species, findings of SNC in dogs ( Canis lups familiaris ) have been inconsistent. This study aimed to investigate the suitability of SNC to assess affective states in dogs. For this purpose, it is important that the test can be consistently used across populations, and we therefore tested the reaction to reward devaluation in laboratory, shelter, and owned dogs (n = 12 per population). After assessing individual food preferences, reward devaluation tasks were performed where animals first solved a puzzle toy for high-value rewards (pre-shift), then for low-value rewards (post-shift), and again for high-value rewards (re-shift). Results showed that shelter dogs and three owned dogs removed fewer cones of the puzzle, ate fewer rewards, and took longer to complete the task (remove all cones) in the post-shift phase compared to pre- and re-shift phases. Conversely, no reduction in number of cones removed nor in number of rewards eaten was found for laboratory and the remaining nine owned dogs. The behaviour of the first group (response reduction following reward devaluation) is consistent with SNC, whereas the behaviour of the second (no change in behaviour after reward devaluation) is not. The inconsistency of SNC within and across dog populations raises questions regarding its suitability for evaluating dog welfare.
... We expected a higher emission of alarm calls in the area with greater anthropogenic disturbance than in the less disturbed one. Additionally, if high-pitched calls are emitted in hostile contexts [16,53] and are related to negative motivational states in animals [54,55], we also predicted that the calls emitted by rock cavies in the more anthropogenically disturbed area would exhibit higher frequencies compared to those from the less disturbed area. ...
Acoustic monitoring is emerging as a key tool in wildlife conservation, especially for species in inaccessible habitats like the rock cavy (Kerodon rupestris), an endangered species native to Brazil’s threatened Caatinga biome. Emotional stress from threatening situations affects breathing, heart rate, and vocal muscle tension, altering vocal acoustic parameters. This allows researchers to gauge the animal’s environmental perception through its vocalizations. We aimed to evaluate emotional disturbance indicators in free-range rock cavies’ vocalizations to suggest an acoustic index during threats. We compared calls from rock cavies in two areas with similar habitats but that differ in terms of anthropic impacts. Area 1 (A1) is near urban areas and disturbed by livestock and dogs, and Area 2 (A2) is farther from urban areas and free from human disturbance. Data on calls and behaviors were collected ad libitum in both areas. The alarm whistle call, making up 73.5% of total calls, was most common. Across 108 observation hours per area, 392 alarm whistle calls were recorded, with more calls in A1 than A2 (223 vs. 169; Chi-square = 29.44, DF = 1, P < 0.001). This resulted in a 32% higher hourly call rate in A1 (2.6 calls/h vs. 1.6 calls/h). Both male and female cavies in A1 had higher high-frequency (F1, 388 = 7.80, P = 0.005) and peak-frequency calls (F1, 388 = 21.32, P < 0.001). Given the similar landscape and resource availability in both areas, the differences in call emission rate and parameters are likely linked to emotional responses to human disturbances in A1. Thus, alarm whistle calls at an hourly rate of 2.6 calls/h or higher, with high-frequency and peak-frequency at or above 7222 Hz and 2603 Hz, can indicate anthropogenic disturbance in the Caatinga biome, aiding remote monitoring efforts.
... In animal welfare research, such optimistic or pessimistic judgements are used to investigate affective states in animals (Harding et al., 2004;Paul et al., 2005). It was shown that animals in a positive affective state make more optimistic judgements compared with animals in a more negative affective state that tend to make more pessimistic decisions Neville et al., 2020). ...
Originating from human psychology, the concept of optimism/pessimism has become increasingly popular in animal welfare science. Typically, so-called judgement bias tests are used to study optimism levels in response to different affect manipulations. Recently, however, evidence is growing that judgement biases not only reflect affective states but might also cover a trait dimension meaning that the optimism level of an individual is stable over time. Contributing to this emerging field of research, we here aimed to comprehensively characterize optimistic and pessimistic rats by repeatedly testing a cohort of Lister Hooded rats in a tactile judgement bias test. To investigate potential links to other behavioural traits, we also assessed the rats' anxiety-like and exploratory behaviour, their laterality and their vocal response to human-induced play behaviour. Furthermore, we studied concentrations of basal faecal corticosterone metabolites to record hypothalamicepituitaryeadrenocortical activity. Therefore, we took all measures twice to assess the stability over time. In contrast to previous studies, we did not find optimism levels to be temporally stable in the present study, encouraging further research on potential factors that might affect or modulate the stability of optimism levels within and across different life phases. Furthermore, we did not detect suites of correlated behaviours, calling for more research on the impact of context and/or species on the emergence of such links. Nevertheless, our results contribute to the accumulating evidence that certain interindividual differences in behaviour, such as exploratory locomotion, vocalizations, anxiety-like behaviour and laterality as well as hypothalamicepituitary eadrenocortical activity, are indeed stable across time and hence can be considered aspects of an ani-mal's personality.
... Social skills help us understand other people's emotions. Instead of reacting instinctively to what we see or hear, we process this information which allows us to respond appropriately and take advantage of opportunities in social environment ultimately improving chances of survival and success (Walters and Sroufe 1983;Paul et al. 2005;Taborsky and Oliveira 2010). ...
Sociosexuality (SO) refers to preferring sexual interactions with or without commitment. Those who prefer long-term relationships have restricted SO, and those who pursue short-term relationships have an unrestricted SO. Sociosexuality may be assessed by Sociosexual Orientation Inventory (SOI-R). Here, we test a new method to assess SO. Respondents are asked to create a personal ad by selecting six out of 10 suggested preferred traits in a partner. Among these 10 traits, there were two traits in each of five evolutionary relevant categories i.e., attractiveness, commitment, resources, cognitive and social skills. We hypothesize that seeking attractiveness/sensuality in a potential partner is related to concentrating on mating investments (higher SOI-R) and to commitment to parental investment (lower SOI-R). Out of 416 subjects who participated in the study, 299 (188 women) were included in the analysis. We found that choosing two traits of attractiveness is related to a less restricted SO, while preference for two commitment traits category characterizes those with a more restrictive SO. No relationship between SOI-R and the preference for cognitive skills or resources was found. Women with more and men with less restricted SO sought partners with better social skills. The proposed new method could be used to assess reproductive strategy.
... Identifying and validating indicators to assess non-human animals' affective states is one of the biggest challenges in animal welfare science. Since we have no direct access to the subjective experience of another individual, we have to rely upon behavioural, physiological and cognitive proxy measures to infer how an animal feels (Paul et al. 2005). A promising cognitive proxy measure of valence, i.e. the positivity or negativity of affective states, are cognitive Judgement Bias Tasks (JBT), in which decisions under ambiguity provide information regarding the underlying affective states of the individual (Mendl et al. 2009). ...
Pigs ( Sus scrofa domesticus ) and most other farmed species are social animals for whom social isolation is known to cause stress. However, their social nature is commonly ignored in behavioural and cognitive tasks, on which they are trained and tested individually, which may impact their welfare and the validity of test results. We chose the Judgement Bias Task (JBT), a promising proxy measure of affective states, to compare training duration, task performance and behaviour of pigs trained and tested in social isolation (ISO; n = 12) with pigs trained and tested with physical and visual contact to social companions through an opening covered with wire mesh (SOC; n = 12). Eleven SOC pigs and eight ISO pigs learned the task, but SOC and ISO pigs did not differ in training duration or task performance when tested. However, ISO pigs showed a higher frequency of all behavioural measures indicative of stress, i.e. high-pitched vocalisation, freezing, exit-approaching behaviour, heavy escape attempts, defaecation and urination compared to SOC pigs. Future research should replicate our study, additionally in combination with other treatments like different housing conditions, to investigate potential interacting effects on learning and task performance. Several open questions remain, but the unambiguous behavioural differences we found strongly advocate for more research to decrease the stress and thus improve the welfare of pigs and other social animals used in behavioural and cognitive tasks.
... Once trained, they are presented with occasional ambiguous cues (e.g., intermediate tones or locations) and their responses recorded. In humans, positive judgements of ambiguity, often referred to as 'optimistic' , are associated with positive affective states and negative judgements ('pessimistic') with negative states [1][2][3][4]. In non-human animals, there is evidence from many studies, including those on dogs [e.g., 5,6,7], that positive (labelled 'optimistic') or negative ('pessimistic') responses to ambiguous cues can be used as markers of positive or negative affective states respectively (for meta-analyses, see: [8,9]). ...
Medical detection dogs search for diseases from remote samples (biodetection) and assist patients with chronic conditions (medical alert assistance). There is scarce information on how dogs’ decision-making tendencies relate to task performance. This study explored the relationships between medical detection dog demographics, responses in a behavioural test battery, ‘optimistic’ or ‘pessimistic’ decisions in a judgement bias task, and their performance in detection tasks. A sample of 58 trainee and trained medical detection dogs were studied in a Go/NoGo spatial judgement bias test. For trainee dogs (n = 39), training outcome (pass/fail) and trainer ratings of behavioural traits; yielding a composite score of ability in detection tasks, were used as markers of task performance. For trained biodetection dogs (n = 27), scent sensitivity and specificity scores derived during training and testing trials were used. Older dogs (p < 0.001), those showing higher ‘Confidence’ (p = 0.009), ‘Food orientation’ (p = 0.014) and ‘Playfulness’ (p = 0.005) in the test battery, and those who made more ‘optimistic’ decisions in the judgement bias task (p = 0.002), had higher detection task ability scores. For trained dogs, latency to approach ambiguous stimuli was positively correlated with scent specificity levels (n = 25, p = 0.021), suggesting that more ‘pessimistic’ dogs tended to be more specific. Our findings suggest relationships between behaviour in judgement bias tests and other learning and discrimination tasks, which may reflect underlying individual or personality differences in affective and/or cognitive processes that influence dogs’ style of searching and performance ability in medical detection tasks. Future research is needed to explore these associations further and investigate the value of judgement bias tasks in predicting later search performance in medical and other types of search dogs.
... The traditional animal emotion research relied primarily on behavioural observations and physiological signal measurements 20 . The behavioural observation method infers emotional states by recording animals' movement patterns 21 ; exploratory behaviours; and specific emotion-related behaviours, such as avoidance, staring, and freezing 22 . ...
A multimodal emotion recognition method that utilizes facial expressions, body postures, and movement trajectories to detect fear in mice is proposed in this study. By integrating and analyzing these distinct data sources through feature encoders and attention classifiers, we developed a robust emotion classification model. The performance of the model was evaluated by comparing it with single-modal methods, and the results showed significant accuracy improvements. Our findings indicate that the multimodal fusion emotion recognition model enhanced the precision of emotion detection, achieving a fear recognition accuracy of 86.7%. Additionally, the impacts of different monitoring durations and frame sampling rates on the achieved recognition accuracy were investigated in this study. The proposed method provides an efficient and simple solution for conducting real-time, comprehensive emotion monitoring in animal research, with potential applications in neuroscience and psychiatric studies.
... Recently cognitive methods have been developed to study an animal's emotional states as well. These methods exploit the fact that cognitive and mental states interact [4,5]. For example, the cognitive-or judgment-bias test allows baseline emotional parameters to be measured by training animals to associate cues with positive or negative outcomes (presumably through classical conditioning of cues). ...
Simple Summary
Although people have strong intuitions about their dogs’ emotions, there is a shortage of scientific information about what dogs may be feeling. Animal emotions are difficult to study because we cannot directly ask them how they are feeling. Consequently, emotional states in animals are studied with cognitive and behavioral tests. Here for the first time, we infer emotional states in dogs using the attention bias test, which has been used in past studies with other animal species. Dogs were first emotionally primed by their owners into positive, neutral or negative emotional states and then entered a testing arena to interact with a novel stimulus. The novel stimulus was a noisy fan intended to produce mild discomfort in the dogs. We observed whether the dogs responded differently to the fan depending on the priming group they were in. We found that dogs in the negative priming group were more likely to pace, stay near the exit, and less likely to vocalize than dogs in the other groups. The behavior of dogs in the positive and neutral groups was not as distinct. These results indicate that the attention bias test is a promising tool for assessing emotional states in dogs. Development of this test can improve our understanding of dog emotions and consequently improve our ability to provide quality care to dogs.
... Emotional state of dairy cattle can also be assessed with a cognitive approach, by testing how cognitive processes (appraisal of stimuli, events, and situations) are affected by emotion (Paul et al., 2005). The judgment bias test evaluates whether animals tend to interpret ambiguous information as more positive or negative (optimism or pessimism) and is now considered a gold standard measure of emotional state in animals (reviewed in Lagisz et al., 2020). ...
This brief symposium review highlights a selection of ways to assess the mental states of dairy cattle, with a focus on positive emotional states and cognitive function and how they are affected by management practices. It highlights behavioral indicators like play, body postures, and grooming; physiological measures such as heart rate variability and peripheral body temperature; and cognitive tests like judgment and attention bias that evaluate differences in information processing. Tests of cognitive function also reveal learning, memory, and cognitive flexibility as measures of mental state. These methods evaluate how management practices-housing, feeding, and enrichment, for example-positively affect the mental states of dairy calves and cows. Emerging technologies offer exciting possibilities for automated, continuous on-farm monitoring that could enable stakeholders of the dairy industry to adapt practices to support welfare and productivity.
... After the 4-month experiment, the horses were subjected to a judgement bias test to assess the effect of social contact on their emotional state. This test is designed to establish how the emotional state of the animal affects its judgement (Paul et al., 2005). It was performed using a spatial GO/NO GO task inspired by the protocol of Henry et al. (2017). ...
... The inclusion of similar behavioural observations in both studies underscores the importance of evaluating equine responses during EAS sessions to ensure not only the welfare of the horse but also the effectiveness of the service. In the present study, behaviours were carefully selected to represent the horse's subjective emotional experiences [87], characterized by both valence (e.g., positive or negative, pleasant or unpleasant) and arousal/intensity level (e.g., contentment versus excitement) [29,88]. While some behaviours arguably indicate a positive or negative valence (ears forward and ears flattened, respectively), others can only be understood when considered alongside a combination of different behaviours. ...
Equine-Assisted Services (EAS) offer significant benefits for individuals with intellectual and/or physical disabilities. However, ensuring the welfare of the horses involved remains a key ethical concern. The objective of this study was to assess the affective states of horses involved in EAS while also establishing behavioural thresholds for indicators of positive or negative affective states. A total of 98 horses were observed over a two-month period, accumulating data about horse behaviour and session characteristics from 830 EAS sessions. Horses participating in coaching programs averaged four sessions in two months; those involved in therapeutic riding averaged 31 sessions. Equine behaviour and field experts defined behavioural thresholds to assess welfare standards. Negative state behaviours were predominantly aligned within excellent or neutral thresholds, while positive state behaviours were observed from unacceptable to excellent. Principal Component Analysis (PCA) of the gathered behavioural data identified six affective states in coaching sessions and four in therapeutic riding, explaining 63% and 73% of the total variation, respectively. Among these states, “comfortable” was the most frequently observed. Multiple linear regression showed several significant variables, highlighting the importance of health, suitable horse selection, and proper management in promoting positive affective states in EAS.
... Animal studies must rely fully on such markers, which often place emphasis on physiological markers and behavioral observations. A drawback of behavioral studies is bias from researchers' subjective perceptions and expectancy biases rooted in other cues or knowledge regarding the animal's state 23 . Observation of contractions of single well-defined muscles is thought to be less prone to bias, and also facilitates consistent recordings of animal facial expressions. ...
Facial expressions in prey animals such as equines can convey information regarding their internal state and are therefore often used as cues for welfare and pain evaluation. The state of pain is commonly compared to a neutral state with little consideration given to other experiences that could affect the animal, although this situation is rare outside of experimental contexts. To evaluate the effect of managerial contexts on facial expressions from a nociceptive input, conspecific isolation and sedation with known physiological effects were compared to compound states of nociception. Using an anatomically based facial action coding system and a short acting pain model, patterns of facial activity could discriminate between horses experiencing conspecific isolation, sedation, and a nociceptive stimulus separately. Nociception occurring together with conspecific isolation could not be discriminated from the conspecific isolation alone, and compound nociception and sedation could not be discriminated from control. While blinking frequency demonstrated potential to be a valuable marker when evaluating a nociceptive stimulus in sedated horses, careful consideration must be given to the biological interpretation of facial expressions during situations where managerial or drug effects may be present.
Supplementary Information
The online version contains supplementary material available at 10.1038/s41598-025-89329-x.
... Play behaviour is widely associated with pleasurable states in animals, as evidenced by behavioural observations (2,3) and extensive neuropharmacological research on rewarding properties of social play in rats (4,5). As a result, play has the potential to positively alter the animals' affective state, including both emotions and longer lasting moods (6,7). Based on this, the performance of play behaviour in farmed pigs has gained importance and has been investigated in relation to the improvements of housing conditions (8,9), a proper development of social skills (10) and other behaviours such as feeding and drinking (11), and reaction to human handling (12). ...
Play behaviour has been suggested to be inherently rewarding for animals, inducing positive emotional states. The psychophysiological effect of emotions can be assessed through heart rate variability (HRV), serving as a proxy measure of sympathovagal balance. This study investigated how the performance of play influences heart rate (HR) and HRV parameters (RMSSD, SDNN) in pigs. It was hypothesized that HRV would increase during and immediately after play due to predominant vagal activation compared to baseline, indicating a positive emotional state. Gilts (n = 32, 18 and 19 weeks of age), housed in standard partly-slatted pens, were selected from two pen-level play treatments: Novelty (NOV) and Play Pen (PLP). Play treatment pigs were reared with intermittent play promotion (3x/week) from 10 weeks of age. For HRV recordings, play was promoted for 15-min in pairs of gilts within treatment, with destructible novel objects given either in the home pen (NOV, 1 m²/pig), or in an enclosed ‘playpen’ area providing extra space (PLP, 2.9 m²/ pig). HRV was measured during a play session in three consecutive periods: (i) baseline (before play bout, no play occurring), (ii) play bout (play expression), and (iii) after-play (immediately after play bout). Twenty-six gilts played at least once. Play bouts lasted between 10 and 30 s (10 s: n = 60, 20 s: n = 18, 30 s: n = 6). In 10-s bouts, compared to baseline, RMSSD was higher during play (p = 0.027) and after-play (p = 0.015), while SDNN increased during play (p ≤ 0.001) and after-play (p = 0.008) only with ambulation (pig moving forward: walking or running). HR did not differ across periods but was higher at ambulation (p = 0.003). Twenty-sec bouts followed the same relationship with only numerical differences, while HRV in 30-s bouts did not differ. Treatments did not influence HRV. Results suggest that engaging in play increases HRV, with this effect persisting into the period immediately after play. This indicates that play contributes to positive emotional states in pigs. Physical activity involved in play influences HRV. More dynamic and energetic play involving ambulation might be more rewarding for pigs. This study provides evidence for assessing positive emotions in pigs and underscores the importance of incorporating rewarding experiences into conventional farming practices.
... To support the use of animal-based indicators in animal care, management, and assessment, a review of peer-reviewed, grey, and selected key literature was conducted to identify animal-based welfare indicators for potential use in calves and cattle. To facilitate appropriate selection, indicators were sorted into the categories of behavioral, physiological, or physical [14,19] and reviewed against the variables of potential affective state, ease of training, cost, equipment, time, and current use in herd health management. This review aims to provide a selection of potential indicators for animal welfare assessments and to promote better animal monitoring to enhance animal welfare, improve production, support research, and maintain public expectations. ...
As the human population continues to rise, so does the consumption of animal proteins and products. To meet this demand, animal agriculture has intensified. Simultaneously, there are increased public concerns related to improving calf and cattle welfare to ensure ethical and sustainable livestock production. To meet these expectations, it is essential to maintain high standards of cattle (Bos taurus and Bos indicus) welfare. The use of animal-based welfare indicators is critical when assessing and developing assessments for animal welfare. A review of calf and cattle animal-based individual and herd health indicators in the scientific and grey literature was conducted. Indicators were initially grouped into the categories of behavioral, physiological, or physical indicators and further analyzed to determine potential affective states, ease of training, cost, special equipment, time, and current use as herd health indicators. The indicators identified in this review have the potential to inform future research priorities, improve animal welfare assessment, and support uplift in animal welfare in cattle production and research to better meet societal expectations of animal care and use.
... These differences become particularly evident when individuals need to make decisions in situations in which the information from the environment is ambiguous and the outcome is uncertain (depicted in the idiom 'Is the glass half full or half empty?'). Based on such decisions in ambiguous situations, a behavioural paradigm, known as the judgement bias test (JBT), has been developed in animal welfare science that allows researchers to characterize nonhuman animals (henceforth: animals) as more 'optimistic' or 'pessimistic' (Harding et al., 2004;Paul et al., 2005). ...
... Some of these (e.g. activation of physiological stress responses) are useful for identifying arousal associated with an emotion but are less informative in terms of valence (Hinde 1985;Paul et al. 2005). Other methods, such as the study of cognitive bias, allow us to infer if an animal is in a more negatively or positively affective state (Mendl et al. 2009). ...
The emotional valence hypothesis suggests an increased left-brain hemisphere activation during positive situations and vice versa during negative situations. Since facial thermal asymmetries may reflect lateralised brain activity, we investigated this in dairy calves subjected to hot-iron disbudding (Disbudded; n = 12) as a model of negative affective states. As affective responses can vary due to previous experiences, we examined whether calves that had (ExpObs; n = 12) and had not (InexObs; n = 12) experienced disbudding differed in their thermal response to a conspecific being disbudded, and whether calf response to the researcher (approaching, moving away, not moving) was associated with thermal asymmetries. We made thermographic recordings of each calf on three days: Day before disbudding (D1); Disbudding day (D2); and Day after disbudding (D3), and at two different times: Disbudding time/1400(T1) and Afternoon/1700(T2). Data were analysed using multilevel models. Calves had warmer left ears on D2 compared to higher temperatures on the right ear on D1, suggesting higher right-hemisphere activity on D2. ExpObs calves had higher left-eye temperatures when observing a conspecific being disbudded (D2×T1) than InexObs calves that had warmer right eyes, but this reversed on the following day (D3×T1). Calves avoiding the researcher had warmer left eyes whereas those approaching him had warmer right eyes, suggesting greater activation of the right hemisphere in the former. This study provides initial evidence of temperature asymmetries when observing or experiencing a negative event. Further work is required to confirm and build upon these early findings. The study highlights the potential for future development of methods using infrared thermography as a proxy measure of affective valence.
... Finally, the physiological responses of animals to puzzle feeders is poorly understood (Meehan & Mench, 2007), making it challenging to directly determine whether feeders are improving an animal's welfare and affective state. For example, an increase in heart rate is often seen in response to both fear and excitement (Paul et al., 2005). Further research into the effects of puzzle feeders on captive animal welfare is therefore required. ...
Problem solving in animals is often studied by measuring an animal's ability to solve man-made puzzles, such as puzzle feeders. Outside of scientific studies, puzzle feeders are also presented to captive animals housed in zoos, aquaria, and sanctuaries as a form of enrichment. Footage of these interactions is commonly posted on social media accounts to increase public engagement with the institution. However, because these puzzle feeders are not presented to animals for research purposes, the problem-solving abilities of numerous species may not be recorded in the scientific literature. Therefore, we searched through three social media platforms (Facebook, Instagram and X) for footage of captive animals solving problems to determine if social media could be a useful tool for behavioural scientists. For each video, we recorded what species was featured, what the puzzle was, how it was solved, and whether this was the first documentation of problem solving for the species (to the best of our knowledge). We found 111 records of successful problem solving across 74 species, including mammals (n = 57), birds (n = 13), and reptiles (n = 4). Overall, this was the first record of problem solving in 29 of these species. We suggest that social media could be a useful tool for researchers studying problem solving, particularly of mammalian and avian species.
... Such a definition highlights the need to take the animals' emotions into account when evaluating their welfare state. Broadly, emotions are defined as short-term affective states (closely linked to internal brain action states) elicited by internal and/or external events which elicit a physiological, behavioural, and cognitive response [15][16][17]. Therefore, the changes produced in animals' behaviour, physiology, and cognition could be measured to derive information on the individuals' affective state [18,19]. ...
Simple Summary
Donkeys are frequently involved in activities with humans, which include educational and recreational activities and therapy (i.e., Animal-Assisted Intervention, AAI). To date, little is known about the factors that could affect animal welfare during AAI. Moreover, no studies have investigated the potential benefit of Donkey-Assisted Intervention on the welfare of migrants hosted by public social services. We observed that human distance from the animal, the interaction mode, and food presence significantly impacted the animal’s behaviours and attitudes toward humans. Furthermore, we provide evidence of the effect of AAI on migrants’ welfare.
... The occurrences of these behaviours have been demonstrated to differ during positive versus negative events in pigs, also in pigs from the present study, and were assumed to be indicative of valence 11 . Time spent standing alert, however, even though generally associated with stress and fear 27,[47][48][49] does not always differ between pigs exposed to positive and negative events 10,11 , and, moreover, even increased in the presence of observer pigs in the present study 11 , likely reflecting heightened attention or arousal rather than a negatively valenced emotional state only. This indicates that this behaviour may not be an unambiguous indicator of a negative state, but may also reflect attention or arousal. ...
Emotional contagion can be defined as the transfer of an emotional state from the demonstrator of that state towards an observer. Social buffering is a process by which the demonstrator has a reduced stress response due to the presence of one or more other individuals. While both processes are well studied separately, it is unknown whether and how both processes are related. Therefore, the aim of this study was to investigate the relation between emotional contagion and social buffering in pigs. Hereto correlations were performed between measures of emotional contagion (i.e., the difference in behaviour of observer pigs between a situation with and without demonstrator pigs present) and measures of social buffering (i.e., the difference in behaviour of demonstrator pigs in a negative situation with and without observer pigs present). The results did not point towards a clear and consistent relation as only few and contrasting correlations between measures of emotional contagion and social buffering were found, and after correcting for chance no significant correlations remained. To conclude, more research is needed on the relation between emotional contagion and social buffering to shed light on how and when emotions will spread through and/or are buffered in a group of animals.
... During the test phase, an ambiguous cue, intermediate between the positive and neutral/negative cue, is presented. Theory and empirical findings indicate that individuals in positive affective states are more likely to behave as if expecting a reward (an 'optimistic' behavioural response) than those in more negative states who show a 'pessimistic' behavioural response [3,4]. ...
Judgement bias tasks (JBTs) are used to assess the emotional state and welfare of animals in zoos, farms and laboratories, based on the interpretation of an ambiguous or intermediate cue. Animals in positive affective states are more likely to interpret the ambiguous cue positively, whereas animals experiencing negative affect are more likely to interpret ambiguous cues pessimistically. Here, we developed a modified JBT assay for the stumpy-spined cuttlefish, Sepia bandensis, to determine whether cuttlefish exhibit negative affective states resulting from external stressors. Positive and neutral visual cues were presented twice daily until animals learned to associate food with the reinforced visual cue. After training, one treatment group was exposed to combined exposure and handling stress produced by 6 days of impoverished housing and simulated net capture. Our control group received no stress experience. In test trials performed after the stress experience, stressed animals showed higher latencies to approach ambiguous cues, spent significantly less time in rooms with ambiguous cues once they entered, and were less likely to enter first into the ambiguous cue-paired room compared with controls. These behaviours suggest that stress induces pessimistic judgement bias in cuttlefish, the first indication of this capacity in cephalopods.
... Emotions are similar but they are also physiologically describable. They have long been viewed as necessarily separate from intellectual activity but it is now shown that they can be facilitators of learning and a consequence of learning (Rolls, 2005;Paul et al., 2005). Indeed, the evaluation of welfare can make use of this, for example, in studies of cognitive bias. ...
Sentience means having the capacity to have feelings. This requires some awareness and cognitive ability. There is evidence for sophisticated cognitive concepts and both positive and negative feelings in many nonhuman animals. Abilities necessary for sentience appear at a certain stage in humans and other species but with brain damage can be lost so not all humans are sentient. All fish, other vertebrates, cephalopod molluscs and decapod crustaceans are sentient. Most people consider that they have moral obligations to many animal species. Moral decisions about abortion, euthanasia, and how humans protect animals should take account of research findings about sentience.
... Empfindungsfähigkeit, kognitive Fähigkeiten) und ihre artspezifischen Bedürfnisse gewandelt hat (u.a. SNEDDON et al.2014;PAUL et al., 2005;MARINO, 2017;BROWN, 2015). Daher erscheint es plausibel, dass heutzutage nur noch circa ein Viertel der Bevölkerung den Umgang mit Tieren anhand ihrer Bezie-hung zu ihnen bewertet. ...
In the recent past, society has increasingly questioned the way animals are treated, especially so-called farm animals. Such ethical values, dealing with the morally correct treatment of animals, affect human behaviour. Therefore, it is of great importance for the agricultural sector in particular to gain a deeper understanding of animal-ethical values in society in order to meet the changing demands. Since such animal-ethical values cover the thematic complex of the human-animal relationship in a very general way and mirror fundamental values, they can be classified in the human value system at the level of domain-specific values. Domain-specific values are characterized by the fact that they are relatively stable over time and are to a certain extent generalizable. The aim of the present study is to develop reliable and valid scales to capture domain-specific values in the context of the human-animal relationship. This is based on core statements of central animal-ethical positions from philosophy. A confirmatory factor analysis reveals that animal-ethical values can be identified in society and that the developed scales are of good reliability and validity. Furthermore, the descriptive results provide a first overview of which animal-ethical values are represented in the German population. Thus, the original anthropocentrism, allowing humans to treat animals as they want, is almost completely rejected. The new contractarian approach (“New Deal”), however, receives an extremely high level of approval. This animal-ethical position in principle allows humans to use animals, but, in exchange, they have to enable them to live a good life.
... Consequently, also conventionally reared pigs kept for meat production likely experience negative emotions and poor welfare. Herein, emotions are defined as brief yet intense reactions to a specific context, involving changes in conscious experience, behavior, cognition, and neurophysiology (Paul et al., 2005;Paul and Mendl, 2018). Emotions encompass two primary components: valence, which pertains to the attractiveness (positive valence) or aversiveness (negative valence) of a stimulus or context, and arousal, indicating the intensity (ranging from low to high) (Mendl et al., 2010;Russel, 2003). ...
... Mildly negative states have also been shown to increase reward valuation, causing individuals to value rewards more when they are considered likely [95][96][97][98] . This is thought to be a way of "relieving" some of the negative emotions by obtaining a positive reward [95][96][97][98] and is in contrast to severe or chronic negative states that result in a devaluation of rewards (anhedonia) 52,[99][100][101] . If the presence of the stress odour caused dogs to experience a mild negative emotional state, they may have been less willing to "risk" approaching a location where they consider a reward to be unlikely (N or NN), i.e., risk-reduction behaviour. ...
Dogs can discriminate stressed from non-stressed human odour samples, but the effect on their cognition is unstudied. Using a cognitive bias task, we tested how human odours affect dogs’ likelihood of approaching a food bowl placed at three ambiguous locations (“near-positive”, “middle” and “near-negative”) between trained “positive” (rewarded) and “negative” (unrewarded) locations. Using odour samples collected from three unfamiliar volunteers during stressful and relaxing activities, we tested eighteen dogs under three conditions: no odour, stress odour and relaxed odour, with the order of test odours counterbalanced across dogs. When exposed to stress odour during session three, dogs were significantly less likely to approach a bowl placed at one of the three ambiguous locations (near-negative) compared to no odour, indicating possible risk-reduction behaviours in response to the smell of human stress. Dogs’ learning of trained positive and negative locations improved with repeated testing and was significant between sessions two and three only when exposed to stress odour during session three, suggesting odour influenced learning. This is the first study to show that without visual or auditory cues, olfactory cues of human stress may affect dogs’ cognition and learning, which, if true, could have important consequences for dog welfare and working performance.
... Development of the rodent tests involves a shift from using emotional stimuli, such as faces, words, or sentences, to cues that are suitable for non-human animals. Building from the observation that cognitive processes such as learning and memory, decisionmaking, and attention are negatively biased in MDD (Mendl et al., 2009;Paul et al., 2005), two key areas have emerged: decision-making biases using a judgement bias task (Harding et al., 2004) and reward learning and memory biases using an affective bias test (Stuart et al., 2013). The first cognitive bias task for rodents was reported by Mendl's group in 2004 when they developed an operant version of a go/no-go judgment bias task for rats (Harding et al., 2004). ...
The Affective Bias Test (ABT) quantifies acute changes in affective state based on the affective biases they generate in an associative reward learning task. The Reward Learning Assay (RLA) provides a control assay for the ABT and reward‐induced biases generated in this model are sensitive to changes in core affective state. Both tasks involve training animals to associate a specific digging substrate with a food reward. Animals learn to discriminate between two digging substrates placed in ceramic bowls, one rewarded and one unrewarded. In the ABT, the animal learns two independent substrate‐reward associations with a fixed reward value following either an affective state or drug manipulation, or under control conditions. Affective biases generated are quantified in a choice test where the animals exhibit a bias (make more choices) for one of the substrates which is specifically related to affective state at the time of learning. The ABT is used to investigate biases generated during learning as well as modulation of biases associated with past experiences. The RLA follows a similar protocol, but the animal remains in the same affective state throughout and a reward‐induced bias is generated by pairing one substrate with a higher value reward. The RLA provides a control to determine if drug treatments affect memory retrieval more generally. Studies in depression models and following environmental enrichment suggest that reward‐induced biases are sensitive to core changes in affective state. Each task offers different insights into affective processing mechanisms and may help improve the translational validity of animal studies and benefit pre‐clinical drug development. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC.
Basic Protocol 1 : Bowl digging and discrimination training
Basic Protocol 2 : The reward learning assay
Basic Protocol 3 : The affective bias test ‐ new learning
Basic Protocol 4 : The affective bias test ‐ modulation of affective biases associated with past experiences
... L'une des principales raisons qui peut expliquer la difficulté à trancher sur la présence ou non d'émotions chez les animaux est peut-être la difficulté de définition du terme « émotion » et sa distinction avec d'autres termes comme « affect », « état émotionnel » ou encore « sentiments » (de Vere and Kuczaj II, 2016). Dans la plupart des études, le terme « émotion » est interchangeable avec celui d'« affect » (Izard et al., 1993;Mendl et al., 2010;Paul et al., 2005). Dans cet écrit nous garderons cette position et nous ne ferons pas la différence entre affect et émotion. ...
... Darwin was the first to argue that emotions and related expressive behaviors are phylogenetically ancient and part of a set of mechanisms that humans share with other animals [1]. Many animal behavior scientists have advocated for the recognition of emotionality, facilitating acceptance of labeling certain animal actions as "emotional" [2][3][4][5][6]. In 1997, the Treaty of Amsterdam recognized the capacity of animals to be sentient. ...
Simple Summary
For humans, music is a powerful tool of emotional communication, conveying affective states and modulating physiological states in ways that can influence well-being. Understanding that emotionality is not an exclusively human trait, as it is also recognized in non-human species, it is natural to assume that the intrinsic power of music to modulate the psychophysiological state may be trans-specific. In this way, music can be a powerful tool for enriching the environment and improving the welfare of captive animals, especially farm animals. As there is very limited information on non-human animals, the aim is to review what is known from a human comparative perspective, arguments that support its use, and the potential to use music in non-human species.
Abstract
The effects of sound stimulation as a sensorial environmental enrichment for captive animals have been studied. When appropriately implemented for farm animals, it can improve welfare, health, and productivity. Furthermore, there are indications that music can induce positive emotions in non-human animals, similar to humans. Emotion is a functional state of the organism involving both physiological processes, mediated by neuroendocrine regulation, and changes in behavior, affecting various aspects, including contextual perception and welfare. As there is very limited information on non-human animals, the objective of this review is to highlight what is known about these processes from human biological and comparative perspectives and stimulate future research on using music to improve animal welfare.
Around the world, guidance for the management of laboratory mice recommends social housing (1-3). However, fighting in male mice represents a major animal welfare and scientific issue. Despite the risks of stress and injury and associated welfare costs of in-cage aggression, we currently prioritise group housing. In this study we first validated a trans-species behavioural biomarker of affective state for mice using a chronic corticosterone model of depression. We next used the same methods to quantify affective state in male mice, group or singly housed in conventional versus individually ventilated cages (IVCs). The results revealed group housed male mice are in a negative affective state similar to that induced by chronic corticosterone treatment. IVC housing was also associated with a more negative affective state. These studies provide an objective assessment of the welfare costs of different housing conditions for male mice.
Affect is a complex interplay of behaviour, physiology, cognition and subjective feelings. The James–Lange theory, which posits that affective bodily responses occur first and subsequently shape our affective experiences, has been extensively studied in humans but remains underexplored in non-human animals. This study employs a judgement bias test to explore the relationship between peripheral bodily responses, specifically self-scratching associated with negative affect, and shifts in cognitive information-processing modes (i.e. a ‘pessimistic’ judgement bias characterized by heightened anticipation of undesirable outcomes) in Japanese macaques (Macaca fuscata). Our findings support the hypothesis that bodily responses precede and influence changes in cognitive modes, demonstrating that self-scratching predicts subsequent pessimistic judgements, but not vice versa. This study provides comparative insights into the biological underpinnings of affect, highlighting that peripheral behaviours can shape cognitive processes in non-human primates. These results have broader implications for understanding the evolutionary continuity and adaptive significance of affective response systems across species.
Originating from human psychology, the concepts of “optimism” and “pessimism” were transferred to animal welfare science about 20 years ago to study emotional states in non‐human animals. Over time, “optimism” and “pessimism” have developed into valuable welfare indicators, but little focus has been put on the ecological implications of this concept. Here, we aim to bridge this gap and underline the great potential for transferring it to behavioural ecology. We start by outlining why “optimism” and “pessimism” can be considered as aspects of animal personalities. Furthermore, we argue that considering “optimism”/“pessimism” in a behavioural ecology context can facilitate our understanding of individual adjustment to the environment. Specifically, we show how variation in “optimism”/“pessimism” can play a crucial role in adaptation processes to environmental heterogeneity, for example, niche choice and niche conformance. Building on these considerations, we hypothesise that “optimists” might be less plastic than “pessimists” in their behaviour, which could considerably affect the way they adjust to environmental change.
The affective state of animals, that is, their mood and emotions, is altered by stressful (negative) or enriching (positive) experiences. In turn, the affective state influences decision making, thereby helping animals when coping with environmental challenges and opportunities. However, it is largely unknown how social experiences modulate the affective state. Here, we performed a judgement bias test to study the effects of rearing group‐size and experimentally assigned current rank on the affective state of the cooperatively‐breeding cichlid fish Neolamprologus pulcher . To assess affective state, we developed and validated a judgement bias test for this species. Fish learned to discriminate between a positive and a negative stimulus as shown by different latencies to approach the stimulus. Furthermore, the response curves to the stimuli conformed to the ones expected in judgement bias tests: fish showed an intermediate latency to approach an ambiguous stimulus, which significantly differed from the latencies to approach the positive and the negative stimulus. Unexpectedly, there were no significant effects of rearing group size and current social rank on the affective state of N. pulcher , despite known effects of these two social parameters on behaviours and physiology of this species. This may mean that observed behavioural and physiological differences in the treatment environments do not allow valid predictions about the affective state elicited by these environments. Alternatively, it may need more socioecologically relevant testing paradigms when evaluating the valence of social environments.
When, if ever, is it better to spend money to improve pig welfare over chicken welfare? Which species of fish is worst off in commercial aquaculture operations? When, if ever, would humans benefit less from a policy than animals stand to lose? The answers to these questions involve making interspecies welfare comparisons—assessments of how well or poorly the members of one species are faring compared to the members of another species. It’s important to answer these questions, as governments, NGOs, and private actors regularly make decisions that assume particular views about them. However, there is no accepted method for making interspecies welfare comparisons; welfare assessment tools are designed to make comparisons within species, not across them. This volume addresses this crucial gap in the literature: it proposes a methodology for making such comparisons, it puts that methodology into practice, and then reports some tentative, proof-of-concept results. This book reports the results of a collaborative, 20-month, interdisciplinary project on making interspecies welfare comparisons. It includes contributions from philosophers, neuroscientists, comparative psychologists, animal welfare scientists, and many others. Unlike many edited volumes, this book is the product of a joint enterprise with a specific, shared goal: to develop a way to make principled comparisons between courses of action that affect different kinds of animals. This book reflects the contributors’ collective view about one way to achieve that goal.
Surgical castration of male piglets is a routine procedure performed to improve meat quality. Prior studies have shown that pain due to castration can last for up to 4 days, negatively impacting animal welfare, however the impact on affect, such as anxiety, is unclear. The objective of this study was to test the application of a novel attention bias test to assess anxiety in piglets that underwent surgical castration with or without practical pain alleviation methods. Piglets were surgically castrated (n = 22), castrated with analgesics (n = 21), or sham-handled (n = 22) at 3 days of age. An attention bias test was performed in week 1 (n = 32, 10–11/treatment) and 12 (n = 29, 9–10/treatment) to assess anxiety (an affective state), with feed (positive stimulus), loud bangs, and flashing lights (negative stimuli) presented simultaneously. Latency to visit the feeder, behavioral responses, and activity were recorded during the test. Additional data on piglets’ activity, tails, and grimaces were collected at three timepoints, at 1, 6, and 24 h after castration to determine pain experience. Piglets’ increased activity (P = 0.065), the fact that fewer piglets visited the feeder (P = 0.029), and tended to have longer latencies to visit the feeder (P = 0.092) in the attention bias test in week 1 might suggest that pain caused by surgical castration increased anxiety. No differences were detected in week 12. Castration treatment and sampling timepoint impacted activity levels hours after treatments, however, other measures were not impacted. These results suggest that more research is needed to determine how affect is impacted by pain caused by surgical castration. Activity and behavioral results somewhat support previous findings that surgical castration causes pain in piglets. As this is the first study assessing the relationship between painful procedures and piglet anxiety, more research is needed to determine a valid method to understand the impacts of these procedures on pig affect.
An emotion is defined as the affective response to a stimulus that leads to specific bodily changes, enabling individuals to react to positive or negative environmental conditions. In the absence of speech, emotions in animals are primarily studied by observing expressive components, such as facial expressions. This review aims to analyze the available literature on the influence of environmental stimuli on measurable behaviors in horses, describing the anatomical components involved in perception at the central nervous system level and the efferent pathways that trigger facial muscle contraction or relaxation, thus altering facial expressions. Additionally, articles addressing the function of facial expressions in communication are discussed, emphasizing their role in social interactions in this species. While there is limited research on equine neurophysiology, considering the common structure of the limbic system in most mammals, studies conducted on canines and primates were taken into account. In conclusion, the article underscores the importance of understanding equine facial expressions to assess their emotional states and, by extension, their welfare.
In previous studies, we have established that anxiety states are characterized by an attentional bias that favors the processing of threatening stimuli. In the present study we extend this finding to ambiguous stimuli, specifically, homophones with spellings that correspond to either a threatening or a neutral meaning. As predicted, clinically anxious subjects used the threatening spellings relatively more than did controls, whereas recovered subjects were intermediate in this respect. Threatening words were associated with greater skin conductance responses than were neutral words, but the groups did not differ in their electrodermal reactions to homophones. We take these findings as evidence that, although the different meanings of ambiguous stimuli may be processed in parallel by all subjects, an interpretive bias operates such that anxiety-prone individuals tend to become preferentially aware of the more threatening meaning of such events.
There has long been interest in describing emotional experience in terms of underlying dimensions, but traditionally only two dimensions, pleasantness and arousal, have been reliably found. The reasons for these findings are reviewed, and integrating this review with two recent theories of emotions (Roseman, 1984; Scherer, 1982), we propose eight cognitive appraisal dimensions to differentiate emotional experience. In an investigation of this model, subjects recalled past experiences associated with each of 15 emotions, and rated them along the proposed dimensions. Six orthogonal dimensions, pleasantness, anticipated effort, certainty, attentional activity, self-other responsibility/control, and situational control, were recovered, and the emotions varied systematically along each of these dimensions, indicating a strong relation between the appraisal of one’s circumstances and one’s emotional state. The patterns of appraisal for the different emotions, and the role of each of the dimensions in differentiating emotional experience are discussed.
At the heart of emotion, mood, and any other emotionally charged event are states experienced as simply feeling good or bad, energized or enervated. These states - called core affect - influence reflexes, perception, cognition, and behavior and are influenced by many causes internal and external, but people have no direct access to these causal connections. Core affect can therefore be experienced as free-floating (mood) or can be attributed to some cause (and thereby begin an emotional episode). These basic processes spawn a broad framework that includes perception of the core-affect-altering properties of stimuli, motives, empathy, emotional meta-experience, and affect versus emotion regulation; it accounts for prototypical emotional episodes, such as fear and anger, as core affect attributed to something plus various nonemotional processes.
Adult rats spontaneously vocalize in ultrasonic frequencies. Although these ultrasonic vocalizations (USVs) have been described as by-products of locomotor activity or social signals, accumulating evidence suggests that they may also index anticipatory affective states. Converging ethological, pharmacological, and brain stimulation research indicates that whereas long low-frequency (> 0.3-s, ∼22-kHz) USVs occur during anticipation of punishment or avoidance behavior, short, high-frequency (< 0.3-s, ∼50-kHz) USVs typically occur during anticipation of reward or approach behavior. Thus, long 22-kHz USVs may index a state of negative activation, whereas short, 50-kHz USVs may instead index a state of positive activation. This hypothesis has theoretical implications for understanding the brain circuitry underlying mammalian affective states and clinical applicability for modeling hedonic properties of different psychotropic compounds.
This book, a member of the Series in Affective Science, is a unique interdisciplinary sequence of articles on the cognitive neuroscience of emotion by some of the most well-known researchers in the area. It explores what is known about cognitive processes in emotion at the same time it reviews the processes and anatomical structures involved in emotion, determining whether there is something about emotion and its neural substrates that requires they be studied as a separate domain. Divided into four major focal points and presenting research that has been performed in the last decade, this book covers the process of emotion generation, the functions of amygdala, the conscious experience of emotion, and emotion regulation and dysregulation. Collectively, the chapters constitute a broad but selective survey of current knowledge about emotion and the brain, and they all address the close association between cognitive and emotional processes. By bringing together diverse strands of investigation with the aim of documenting current understanding of how emotion is instantiated in the brain, this book will be of use to scientists, researchers, and advanced students of psychology and neuroscience.
This is a book. The Preface describing contents is uploaded.
The main functions attributed to vigilance are: detection of predators, observation of group members, location of food and avoidance of kleptoparasitism. Individual vigilance generally decreases and collective vigilance increases with increasing group size; peripheral individuals are more vigilant than central ones; and males scan more than females during rutting. Contradictory results concerning the influence of age, social rank, habitat and proximity of refuge do not allow determination of obvious relationships. Modelling vigilance behaviour consists in estimating individual survival probability which would depend directly on the tradeoff between foraging and vigilance behaviour. -from Author
Describes experiments in which happy or sad moods were induced in Ss by hypnotic suggestion to investigate the influence of emotions on memory and thinking. Results show that (a) Ss exhibited mood-state-dependent memory in recall of word lists, personal experiences recorded in a daily diary, and childhood experiences; (b) Ss recalled a greater percentage of those experiences that were affectively congruent with the mood they were in during recall; (c) emotion powerfully influenced such cognitive processes as free associations, imaginative fantasies, social perceptions, and snap judgments about others' personalities; (d) when the feeling-tone of a narrative agreed with the reader's emotion, the salience and memorability of events in that narrative were increased. An associative network theory is proposed to account for these results. In this theory, an emotion serves as a memory unit that can enter into associations with coincident events. Activation of this emotion unit aids retrieval of events associated with it; it also primes emotional themata for use in free association, fantasies, and perceptual categorization. (54 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
This book, a member of the Series in Affective Science, is a unique interdisciplinary sequence of articles on the cognitive neuroscience of emotion by some of the most well-known researchers in the area. It explores what is known about cognitive processes in emotion at the same time it reviews the processes and anatomical structures involved in emotion, determining whether there is something about emotion and its neural substrates that requires they be studied as a separate domain. Divided into four major focal points and presenting research that has been performed in the last decade, this book covers the process of emotion generation, the functions of amygdala, the conscious experience of emotion, and emotion regulation and dysregulation. Collectively, the chapters constitute a broad but selective survey of current knowledge about emotion and the brain, and they all address the close association between cognitive and emotional processes. By bringing together diverse strands of investigation with the aim of documenting current understanding of how emotion is instantiated in the brain, this book will be of use to scientists, researchers, and advanced students of psychology and neuroscience.
This book brings together a range of scientific perspectives from biomedical research on stress and welfare, and assesses new approaches to conceptualizing and alleviating stress. While much of the focus in on conventional farm animals, there is also consideration of fishes, laboratory animals and zoo animals. The 30 contributors include leading authorities from North America, Europe, New Zealand and Australia. This book is invaluable for advanced students and researchers in animal behaviour, animal welfare, animal production, veterinary medicine and applied psychology. For more information see the CABI Publishing online bookshop (http://www.cabi.org/Bookshop/).
Wild animals increase vigilance at the expense of feeding time in response to predation risk or threats from conspecifics. Increased vigilance may therefore indicate increased fear. We tested dairy cattle to determine whether time spent vigilant changed in response to the novelty of their location, the presence of a dog or the presence of an aversive, gentle or unfamiliar handler. We conducted 12 3 min trials per cow on 40 cows tested individually in a large outdoor enclosure containing an attractive food source. The feeders restricted the animal’s view so that it could not feed and scan simultaneously, so vigilance time was defined as any time the animal’s head was raised. During the initial trials, the degree of vigilance was high, but the amount of vigilance decreased significantly with number of trials. Time vigilant was significantly higher in the presence of a dog than in the presence of a human or when neither was present. In a second experiment, 20 cows, that had been trained to recognise an aversive and a gentle person for 3 weeks prior to testing, were tested in an indoor pen containing an attractive food source with the aversive, gentle, or an unfamiliar person nearby. The presence of the aversive person significantly increased vigilance time compared to the unfamiliar and gentle people. However, vigilance time did not decrease with repeated exposure to the enclosure, perhaps because the testing barn was already familiar. These results suggest that cows alter their vigilance according to their degree of fearfulness toward people and toward different environments, and that measures of vigilance may provide information on the degree of fearfulness of the animals.
Four essential modifications in my affect theory are presented. First, an ambiguity in the concept of affect as amplification has been revised so that the affect is now considered to be an analogic amplifier in much the same manner as pain is an analogic amplifier of the injury it amplifies. Second, I now view the skin of the face as more essential than its musculature in providing the feedback which we experience as motivating. It is shown also that the skin in general is a powerful motivational organ in sex, pain, and sleep. Third, I now view innate affect as essentially suppressed and backed up in the adult, exacting a price whose cost is yet to be precisely determined. The mechanism by which this is achieved is through suppression of vocalization of affect. Fourth, I now view the affect as amplifying not only its activation but also the response to the affect, because it coexists with and thereby imprints its form on whatever response follows it.
Two widely held assumptions about the sounds of birds and other animals are (1) they are impulsive and involuntary, and cannot be controlled, and (2) they are based only on emotion, apparently because the stimuli eliciting them are thought to be very generalized. The validity of these assumptions has been tested in studies of the alarm calling and food calling behavior of domestic chickens. Videotapes of aerial and ground predators - a hawk overhead and a raccoon on the ground - were effective in eliciting the two major classes of alarm calls. The frequency of aerial alarm calling was strongly affected by presence or absence of a companion, while other aspects of antipredator behavior were unchanged. This so-called "audience effect" on calling is not found with the ground predator call, apparently because this call is addressed to the predator as well as companions. The rules for audience effects are different again with food calling. Evidently calling is not completely impulsive, but can be controlled. By varying the attributes of digitized video images of predators we have shown that stimuli eliciting the aerial predator alarm call are quite specific, encoding different information than the ground predator call. Playback experiments demonstrate that another chicken can decode this information, and react adaptively. Although emotion is undoubtedly involved in bird calling, we conclude that simple emotion-based models of bird calls are inadequate as the sole basis for explaining the vocal behavior of birds.
The study investigated selective processing of emotional information in anxiety and depression using a modified Stroop color naming task. Anxious (n = 19), depressed (n = 18), and normal control (n = 18) subjects were required to name the background colors of anxiety-related, depression-related, positive, categorized, and uncategorized neutral words. Half of the words were presented supraliminally, half subliminally. Anxious subjects, compared with depressed and normal subjects, showed relatively slower color naming for both supraliminal and subliminal negative words. The results suggest a preattentive processing bias for negative information in anxiety.
This chapter explores the multiple effects of emotion on memory and argues that there are several levels of complexity in human emotional learning not captured by the known neurobiological mechanisms. It suggests ways in which these complex phenomena might be approached from a biological perspective. It also discusses emotional memories and arousal. Emotional events are accompanied by strong arousal. The arousal is accompanied by, or perhaps consists of, a series of changes in body chemistry, and these changes promote brain processes responsible for the encoding of new information. With this enhanced encoding in place, it is no wonder that subsequent recollection is fuller and more detailed for emotional events. This kind of account is, of course, consistent with the correlational data given in this chapter, and also the obvious facts about flashbulb memories and posttraumatic stress disorder.
Naturalistic observation at a bowling alley (N = 1,793 balls) shows that bowlers often smiled when socially engaged, looking at and talking to others, but not necessarily after scoring a spare or a strike. In a 2nd study, bowlers (N = 166 balls) rarely smiled while facing the pins but often smiled when facing their friends. At a hockey game, fans (N = 3,726 faces) smiled both when they were socially involved and after events favorable to their team. Pedestrians (N = 663) were much more likely to smile when talking but only slightly more likely to smile in response to nice weather than to unpleasant weather. These 4 studies suggest a strong and robust association of smiling with a social motivation and an erratic association with emotional experience. (29 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
This chapter examines some of the literature demonstrating an impact of affect on social behavior. It will consider the influence of affect on cognition in an attempt to further understand on the way cognitive processes may mediate the effect of feelings on social behavior. The chapter describes the recent works suggesting an influence of positive affect on flexibility in cognitive organization (that is, in the perceived relatedness of ideas) and the implications of this effect for social interaction. The goal of this research is to expand the understanding of social behavior and the factors, such as affect, that influence interaction among people. Another has been to extend the knowledge of affect, both as one of these determinants of social behavior and in its own right. And a third has been to increase the understanding of cognitive processes, especially as they play a role in social interaction. Most recently, cognitive and social psychologists have investigated ways in which affective factors may participate in cognitive processes (not just interrupt them) and have begun to include affect as a factor in more comprehensive models of cognition. The research described in the chapter has focused primarily on feelings rather than intense emotion, because feelings are probably the most frequent affective experiences. The chapter focuses primarily on positive affect.
The present experiments were designed to examine the effect of posttraining glucose injections on the acquisition of two appetitive tasks in an 8-arm radial maze. On a win-stay visual discrimination task, the presence of food in four randomly selected maze arms was signaled by a light cue, and rats were required to visit each of the four lit arms twice within a trial. The animals were given one trial per day and injected immediately posttraining on Day 5. A dose of 2.0 g/kg glucose significantly improved win-stay acquisition relative to the performance of controls, but a dose of 100 mg/kg had no effect. On a win-shift task, rats were allowed to obtain food from four randomly selected maze arms, followed by a delay period in which they were removed from the maze. The animals were returned to the maze for a retention test, in which only the arms that had not been visited prior to the delay contained food. After training on shorter delays, 18 h were imposed between the first and second four choices; glucose was injected immediately after the first four choices. Glucose doses of both 2.0 g/kg and 100 mg/kg significantly improved retention, relative to that of controls. The results demonstrate that the memory-improving action of glucose generalizes to appetitive tasks, and they suggest that glucose can improve memory in appetitive tasks with different mnemonic requirements.
Some investigators have argued that emotions, especially animal emotions, are illusory concepts outside the realm of scientific inquiry. With advances in neurobiology and neuroscience, however, researchers are proving this position wrong while moving closer to understanding the biology and psychology of emotion. In Affective Neuroscience, Jaak Panksepp argues that emotional systems in humans, as well as other animals, are necessarily combinations of innate and learned tendencies; there are no routine and credible ways to really separate the influences of nature and nurture in the control of behavior. The book shows how to move toward a new understanding by taking a psychobiological approach to the subject, examining how the neurobiology and neurochemistry of the mammalian brain shape the psychological experience of emotion. It includes chapters on sleep and arousal, pleasure and pain systems, the sources of rage and anger, and the neural control of sexuality. The book will appeal to researchers and professors in the field of emotion.
This chapter describes the limited empirical evidence concerning the functions of play and suggests some possible reasons, both theoretical and methodological, as why evidence in support of functional hypotheses has not been forthcoming. It describes certain assumptions about play, which pervade the biological literature, for example, that early play experience is crucial for the normal development and that play is a very costly activity and so must have major benefits. It is analyzed that these assumptions are mostly without empirical support and reflect an underlying view of behavioral development that is highly questionable. Criticisms of current explanations of play are presented in the chapter in a constructive spirit. Play remains a biological enigma, which demands closer scrutiny. At present, there is no direct evidence that play has any important benefits, with the possible exception of some immediate effects on children's behavior. The problem of confounding variables and the need for multiple, sensitive, and functionally relevant outcome measures in future experiments are discussed.
The proposition was tested that depressives make predictions about the future based on a pessimistic future-event schema. Participants varying in depression predicted whether positive and negative events would happen to them (or to an average person) in the future by pressing yes or no at a computer terminal as quickly as possible, either under a concurrent attentional load or under no such load. As hypothesized, depressives predicted more negative events and fewer positive events than did mild depressives or nondepressives and showed greater automaticity in their predictions. That is, the attentional load did not increase depressives' response latencies for either negative or positive events, even though it did so reliably for both mildly depressed and nondepressed individuals. Depressives may thus possess a highly developed future-event schema that operates efficiently in enabling future-event predictions.
Previous research has established that anxiety patients demonstrate a cognitive bias that selectively favours the processing of threat related information. The current experiment employs a variant of a well established colour naming paradigm to address three issues concerning the nature of this anxiety linked pattern of selective processing. First, by considering non-clinical subjects and employing an experimental design capable of dissociating the influence of state and trait anxiety, the current study addresses the hypothesis that state anxiety elevations will elicit differential patterns of selectivity in high and low trait anxious subjects. Second, by presenting stimulus materials within or outside awareness, the study addresses the hypothesis that these processing biases occur automatically, without requiring the use of consciously mediated strategies. Third, by including both emotionally valenced stimulus materials which are related to, and which are unrelated to, the particular source of stress experienced by the subjects, the experiment addresses the hypothesis that such anxiety linked processing biases will be restricted to materials falling within the domain of current personal concern. The results of the present study clearly demonstrate that these three issues are not independent. Fundamentally different patterns of anxiety linked selective processing were observed when stimuli were presented outside awareness, permitting only automatic cognitive processing, and when stimuli were presented within awareness, permitting the use of consciously mediated strategies. The relative roles played by state and trait variables, and the degree to which these effects were influenced by the personal relevance of the stimulus materials, differed in each case. The implications of these findings for future research in this field are discussed.
Strains of mice that show characteristic patterns of behavior are critical for research in neurobehavioral genetics. Possible
confounding influences of the laboratory environment were studied in several inbred strains and one null mutant by simultaneous
testing in three laboratories on a battery of six behaviors. Apparatus, test protocols, and many environmental variables were
rigorously equated. Strains differed markedly in all behaviors, and despite standardization, there were systematic differences
in behavior across labs. For some tests, the magnitude of genetic differences depended upon the specific testing lab. Thus,
experiments characterizing mutants may yield results that are idiosyncratic to a particular laboratory.
The difficulties inherent in obtaining consistent and adequate diagnoses for the purposes of research and therapy have been pointed out by a number of authors. Pasamanick12 in a recent article viewed the low interclinician agreement on diagnosis as an indictment of the present state of psychiatry and called for "the development of objective, measurable and verifiable criteria of classification based not on personal or parochial considerations, but on behavioral and other objectively measurable manifestations."Attempts by other investigators to subject clinical observations and judgments to objective measurement have resulted in a wide variety of psychiatric rating scales.4,15 These have been well summarized in a review article by Lorr11 on "Rating Scales and Check Lists for the Evaluation of Psychopathology." In the area of psychological testing, a variety of paper-and-pencil tests have been devised for the purpose of measuring specific
Broiler chickens, Gallus gallus domesticus, have been selected for rapid weight gain and appear to be continously hungry. If this is so, then energy that broilers invest in obtaining food should be insensitive to their level of feed restriction. We tested this hypothesis by measuring the maximum price (i.e. maximum number of key pecks) broilers with different body weights would pay for a food reward under conditions of varying feed restriction. Two groups of 20 broilers were fed on 50 or 75% of the amount of feed a broiler would eat when fed ad libitum. Broilers were able to learn an operant task and were willing to work for food. Birds of the 50%-group paid a higher maximum price for a food reward and responded more quickly to food presentation than the birds of the 75%-group in the first test week and showed a nonsignificant tendency to pay a higher price and to respond more quickly in the second test week. Different levels of long-term feed restriction had an influence on their body weight and on their motivation to work for food. No short-term effect of changing feed restriction was found. Birds showed frustration behaviour after the last food reward had been obtained, indicating that they were still hungry. The results indicate that broilers are still sensitive to different levels of feed restriction and that they can balance their investments and profits to a certain extent.
