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Küster D, Baker M, Krumhuber EG. PDSTD - The Portsmouth Dynamic Spontaneous Tears Database. Behav Res Methods 2022; 54:2678-2692. [PMID: 34918224 PMCID: PMC9729121 DOI: 10.3758/s13428-021-01752-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2021] [Indexed: 12/16/2022]
Abstract
The vast majority of research on human emotional tears has relied on posed and static stimulus materials. In this paper, we introduce the Portsmouth Dynamic Spontaneous Tears Database (PDSTD), a free resource comprising video recordings of 24 female encoders depicting a balanced representation of sadness stimuli with and without tears. Encoders watched a neutral film and a self-selected sad film and reported their emotional experience for 9 emotions. Extending this initial validation, we obtained norming data from an independent sample of naïve observers (N = 91, 45 females) who watched videos of the encoders during three time phases (neutral, pre-sadness, sadness), yielding a total of 72 validated recordings. Observers rated the expressions during each phase on 7 discrete emotions, negative and positive valence, arousal, and genuineness. All data were analyzed by means of general linear mixed modelling (GLMM) to account for sources of random variance. Our results confirm the successful elicitation of sadness, and demonstrate the presence of a tear effect, i.e., a substantial increase in perceived sadness for spontaneous dynamic weeping. To our knowledge, the PDSTD is the first database of spontaneously elicited dynamic tears and sadness that is openly available to researchers. The stimuli can be accessed free of charge via OSF from https://osf.io/uyjeg/?view_only=24474ec8d75949ccb9a8243651db0abf .
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Affiliation(s)
- Dennis Küster
- Department of Mathematics and Computer Science, University of Bremen, Enrique-Schmidt Str. 5, 28359, Bremen, Germany.
| | - Marc Baker
- Department of Psychology, University of Portsmouth, Portsmouth, UK
| | - Eva G Krumhuber
- Department of Experimental Psychology, University College London, London, UK
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Folz J, Fiacchino D, Nikolić M, van Steenbergen H, Kret ME. Reading Your Emotions in My Physiology? Reliable Emotion Interpretations in Absence of a Robust Physiological Resonance. AFFECTIVE SCIENCE 2022; 3:480-497. [PMID: 35282156 PMCID: PMC8901434 DOI: 10.1007/s42761-021-00083-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 09/12/2021] [Indexed: 11/26/2022]
Abstract
Affective states are expressed in an individual’s physical appearance, ranging from facial expressions and body postures, to indicators of physiological arousal (e.g., a blush). Confirming the claimed communicative function of these markers, humans are capable of distinguishing between a variety of discrete emotion displays. In an attempt to explain the underlying mechanism, characteristic bodily changes within the observer, including physiological arousal and mimicry, have been suggested to facilitate the interpretation of an expression. The current study aims to create a holistic picture of emotion perception by (1) using three different sources of emotional information (prototypical facial expressions, bodily expressions, and subtle facial cues) and (2) measuring changes in multiple physiological signals (facial electromyography, skin conductance level, skin temperature, and pupil size). While participants clearly discriminated between perceived emotional expressions, there was no overall 1–1 correspondence with their physiological responses. Some specific but robust effects were observed. Angry facial expressions were consistently responded to with a peak in skin conductance level. Furthermore, sad body expressions were associated with a drop in skin temperature. In addition to being the best recognized expression, viewing happy faces elicited congruent facial muscle responses, which supports the potential role of embodied simulation in emotion recognition. Lastly, tears were not only rated as highly emotional intense but also evoked a peak in skin conductance level in the observer. The absence of distinct physiological responses to other expressions could be explained by the lacking functionality of affect sharing in a non-interactive experimental context. Consequentially, emotional alignment in body and mind might especially take place in real social situations, which should be considered in future research.
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Affiliation(s)
- Julia Folz
- Department of Cognitive Psychology, Institute of Psychology, Leiden University, Leiden, 2333 AK The Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, 2300 RC The Netherlands
| | - Donatella Fiacchino
- Department of Cognitive Psychology, Institute of Psychology, Leiden University, Leiden, 2333 AK The Netherlands
| | - Milica Nikolić
- Department of Cognitive Psychology, Institute of Psychology, Leiden University, Leiden, 2333 AK The Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, 2300 RC The Netherlands
- Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, 1018 WS The Netherlands
| | - Henk van Steenbergen
- Department of Cognitive Psychology, Institute of Psychology, Leiden University, Leiden, 2333 AK The Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, 2300 RC The Netherlands
| | - Mariska E. Kret
- Department of Cognitive Psychology, Institute of Psychology, Leiden University, Leiden, 2333 AK The Netherlands
- Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, 2300 RC The Netherlands
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van Kleef GA, Lelieveld GJ. Moving the self and others to do good: The emotional underpinnings of prosocial behavior. Curr Opin Psychol 2021; 44:80-88. [PMID: 34592600 DOI: 10.1016/j.copsyc.2021.08.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/18/2022]
Abstract
The functioning of social collectives hinges on the willingness of their members to cooperate with one another and to help those who are in need. Here, we consider how such prosocial behavior is shaped by emotions. We offer an integrative review of theoretical arguments and empirical findings concerning how the experience of emotions influences people's own prosocial behavior (intrapersonal effects) and how the expression of emotions influences the prosocial behavior of others (interpersonal effects). We identified research on five broad clusters of emotions associated with opportunity and affiliation (happiness, contentment, hope), appreciation and self-transcendence (gratitude, awe, elevation, compassion), distress and supplication (sadness, disappointment, fear, anxiety), dominance and status assertion (anger, disgust, contempt, envy, pride), and appeasement and social repair (guilt, regret, shame, embarrassment). Our review reveals notable differences between emotion clusters and between intrapersonal and interpersonal effects. Although some emotions promote prosocial behavior in the self and others, most emotions promote prosocial behavior either in the self (via their intrapersonal effects) or in others (via their interpersonal effects), suggesting trade-offs between the functionality of emotional experience and emotional expression. Moreover, interpersonal effects are modulated by the cooperative versus competitive nature of the situation. We discuss the emerging patterns from a social-functional perspective and conclude that understanding the role of emotion in prosociality requires joint attention to intrapersonal and interpersonal effects.
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Zickfeld JH, van de Ven N, Pich O, Schubert TW, Berkessel JB, Pizarro JJ, Bhushan B, Mateo NJ, Barbosa S, Sharman L, Kökönyei G, Schrover E, Kardum I, Aruta JJB, Lazarevic LB, Escobar MJ, Stadel M, Arriaga P, Dodaj A, Shankland R, Majeed NM, Li Y, Lekkou E, Hartanto A, Özdoğru AA, Vaughn LA, del Carmen Espinoza M, Caballero A, Kolen A, Karsten J, Manley H, Maeura N, Eşkisu M, Shani Y, Chittham P, Ferreira D, Bavolar J, Konova I, Sato W, Morvinski C, Carrera P, Villar S, Ibanez A, Hareli S, Garcia AM, Kremer I, Götz FM, Schwerdtfeger A, Estrada-Mejia C, Nakayama M, Ng WQ, Sesar K, Orjiakor CT, Dumont K, Allred TB, Gračanin A, Rentfrow PJ, Schönefeld V, Vally Z, Barzykowski K, Peltola HR, Tcherkassof A, Haque S, Śmieja M, Su-May TT, IJzerman H, Vatakis A, Ong CW, Choi E, Schorch SL, Páez D, Malik S, Kačmár P, Bobowik M, Jose P, Vuoskoski JK, Basabe N, Doğan U, Ebert T, Uchida Y, Zheng MX, Mefoh P, Šebeňa R, Stanke FA, Ballada CJ, Blaut A, Wu Y, Daniels JK, Kocsel N, Burak EGD, Balt NF, Vanman E, Stewart SL, Verschuere B, Sikka P, Boudesseul J, Martins D, Nussinson R, Ito K, Mentser S, Çolak TS, Martinez-Zelaya G, Vingerhoets A. Tears evoke the intention to offer social support: A systematic investigation of the interpersonal effects of emotional crying across 41 countries. JOURNAL OF EXPERIMENTAL SOCIAL PSYCHOLOGY 2021. [DOI: 10.1016/j.jesp.2021.104137] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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5
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Zickfeld JH, van de Ven N, Pich O, Schubert TW, Berkessel JB, Pizarro JJ, Bhushan B, Mateo NJ, Barbosa S, Sharman L, Kökönyei G, Schrover E, Kardum I, Aruta JJB, Lazarevic LB, Escobar MJ, Stadel M, Arriaga P, Dodaj A, Shankland R, Majeed NM, Li Y, Lekkou E, Hartanto A, Özdoğru AA, Vaughn LA, del Carmen Espinoza M, Caballero A, Kolen A, Karsten J, Manley H, Maeura N, Eşkisu M, Shani Y, Chittham P, Ferreira D, Bavolar J, Konova I, Sato W, Morvinski C, Carrera P, Villar S, Ibanez A, Hareli S, Garcia AM, Kremer I, Götz FM, Schwerdtfeger A, Estrada-Mejia C, Nakayama M, Ng WQ, Sesar K, Orjiakor CT, Dumont K, Allred TB, Gračanin A, Rentfrow PJ, Schönefeld V, Vally Z, Barzykowski K, Peltola HR, Tcherkassof A, Haque S, Śmieja M, Su-May TT, IJzerman H, Vatakis A, Ong CW, Choi E, Schorch SL, Páez D, Malik S, Kačmár P, Bobowik M, Jose P, Vuoskoski JK, Basabe N, Doğan U, Ebert T, Uchida Y, Zheng MX, Mefoh P, Šebeňa R, Stanke FA, Ballada CJ, Blaut A, Wu Y, Daniels JK, Kocsel N, Burak EGD, Balt NF, Vanman E, Stewart SL, Verschuere B, Sikka P, Boudesseul J, Martins D, Nussinson R, Ito K, Mentser S, Çolak TS, Martinez-Zelaya G, Vingerhoets A. Tears evoke the intention to offer social support: A systematic investigation of the interpersonal effects of emotional crying across 41 countries. JOURNAL OF EXPERIMENTAL SOCIAL PSYCHOLOGY 2021. [DOI: https://doi.org/10.1016/j.jesp.2021.104137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Picó A, Gadea M. When animals cry: The effect of adding tears to animal expressions on human judgment. PLoS One 2021; 16:e0251083. [PMID: 33956813 PMCID: PMC8101718 DOI: 10.1371/journal.pone.0251083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/19/2021] [Indexed: 12/02/2022] Open
Abstract
At a time of growing interest in and awareness about the relationships between humans and animals, it is of relevance to scientifically analyse the intrinsic nature of these interactions. Reactions to emotional tears show our extraordinary capacity for detecting micro-nuances when judging another human’s face. Regarding such behaviour, previous studies carried out in our laboratory have pointed to an adaptive function of emotional tears: i.e. their inhibitory influence on perceived aggressiveness. In the present work we aimed to further explore that hypothesis by extending our investigation from humans to animals, using pictures of five different animal faces (cat, dog, horse, chimpanzee, hamster) to which tears were added digitally. To this end, we conducted an online study of 403 participants recruited from different social networks and academic institutions. We questioned the participants about their perceptions of emotional intensity, aggressiveness and friendliness in the animal faces and analysed the comparisons they made between faces with and without tears. In addition, a latent variable referred to as “passion for animals” was measured using different indicators. By adding the results obtained in each species and breaking them down into different basic emotions, we found that the presence of tears was related to a higher absolute frequency of participants who perceived sadness, which endorsed our previous results obtained using images of humans. Regarding aggressiveness, the presence of tears favoured the perception of less aggressiveness. A structural equation model was also conducted to explore the relations among all the measured variables. The model confirmed that the presence of tears in the animal faces had a significant influence on the perception of higher emotional intensity and friendliness, and of lower aggressiveness.
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Affiliation(s)
- Alfonso Picó
- Department of Psychobiology, Faculty of Psychology, Universitat de València, Valencia, Spain
| | - Marien Gadea
- Department of Psychobiology, Faculty of Psychology, Universitat de València, Valencia, Spain
- Center of Network Biomedical Investigation - Mental Health (CIBERSAM), Madrid, Spain
- * E-mail:
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7
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How Weeping Influences the Perception of Facial Expressions: The Signal Value of Tears. JOURNAL OF NONVERBAL BEHAVIOR 2021. [DOI: 10.1007/s10919-020-00347-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Picó A, Espert R, Gadea M. How Our Gaze Reacts to Another Person's Tears? Experimental Insights Into Eye Tracking Technology. Front Psychol 2020; 11:2134. [PMID: 32982872 PMCID: PMC7492655 DOI: 10.3389/fpsyg.2020.02134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/30/2020] [Indexed: 02/03/2023] Open
Abstract
Crying is an ubiquitous human behavior through which an emotion is expressed on the face together with visible tears and constitutes a slippery riddle for researchers. To provide an answer to the question "How our gaze reacts to another person's tears?," we made use of eye tracking technology to study a series of visual stimuli. By presenting an illustrative example through an experimental setting specifically designed to study the "tearing effect," the present work aims to offer methodological insight on how to use eye-tracking technology to study non-verbal cues. A sample of 30 healthy young women with normal visual acuity performed a within-subjects task in which they evaluated images of real faces with and without tears while their eye movements were tracked. Tears were found to be a magnet for visual attention in the task of facial attribution, facilitating a greater perception of emotional intensity. Moreover, the inspection pattern changed qualitatively and quantitatively, with our participants becoming fully focused on the tears when they were visible. The mere presence of a single tear running down a cheek was associated with an increased emotional inference and greater perception of sincerity. Using normalized and validated tools (Reading the Eyes in the Mind Test and the SALAMANCA screening test for personality disorders), we measured the influence of certain characteristics of the participants on their performance of the experimental task. On the one hand, a higher level of cognitive empathy helped to classify tearful faces with higher emotional intensity and tearless faces with less emotional intensity. On the other hand, we observed that less sincerity was attributed to the tearful faces as the SALAMANCA test scores rose in clusters A (strange and extravagant) and B (immature and emotionally unstable) of our sample. The present findings highlight the advantages of using eye tracking technology to study non-verbal cues and draw attention to methodological issues that should be taken into account. Further exploration of the relationship between empathy and tear perception could be a fruitful avenue of future research using eye tracking.
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Affiliation(s)
- Alfonso Picó
- Department of Psychobiology, Faculty of Psychology, Universitat de València, Valencia, Spain
| | - Raul Espert
- Department of Psychobiology, Faculty of Psychology, Universitat de València, Valencia, Spain
| | - Marien Gadea
- Department of Psychobiology, Faculty of Psychology, Universitat de València, Valencia, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM)-Mental Health, Madrid, Spain
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Küster D, Krumhuber EG, Steinert L, Ahuja A, Baker M, Schultz T. Opportunities and Challenges for Using Automatic Human Affect Analysis in Consumer Research. Front Neurosci 2020; 14:400. [PMID: 32410956 PMCID: PMC7199103 DOI: 10.3389/fnins.2020.00400] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/31/2020] [Indexed: 11/13/2022] Open
Abstract
The ability to automatically assess emotional responses via contact-free video recording taps into a rapidly growing market aimed at predicting consumer choices. If consumer attention and engagement are measurable in a reliable and accessible manner, relevant marketing decisions could be informed by objective data. Although significant advances have been made in automatic affect recognition, several practical and theoretical issues remain largely unresolved. These concern the lack of cross-system validation, a historical emphasis of posed over spontaneous expressions, as well as more fundamental issues regarding the weak association between subjective experience and facial expressions. To address these limitations, the present paper argues that extant commercial and free facial expression classifiers should be rigorously validated in cross-system research. Furthermore, academics and practitioners must better leverage fine-grained emotional response dynamics, with stronger emphasis on understanding naturally occurring spontaneous expressions, and in naturalistic choice settings. We posit that applied consumer research might be better situated to examine facial behavior in socio-emotional contexts rather than decontextualized, laboratory studies, and highlight how AHAA can be successfully employed in this context. Also, facial activity should be considered less as a single outcome variable, and more as a starting point for further analyses. Implications of this approach and potential obstacles that need to be overcome are discussed within the context of consumer research.
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Affiliation(s)
- Dennis Küster
- Cognitive Systems Lab, Department of Mathematics and Computer Science, University of Bremen, Bremen, Germany.,Department of Psychology and Methods, Jacobs University Bremen, Bremen, Germany
| | - Eva G Krumhuber
- Department of Experimental Psychology, University College London, London, United Kingdom
| | - Lars Steinert
- Cognitive Systems Lab, Department of Mathematics and Computer Science, University of Bremen, Bremen, Germany
| | - Anuj Ahuja
- Maharaja Surajmal Institute of Technology, Guru Gobind Singh Indraprastha University, New Delhi, India
| | - Marc Baker
- Centre for Situated Action and Communication, Department of Psychology, University of Portsmouth, Portsmouth, United Kingdom
| | - Tanja Schultz
- Cognitive Systems Lab, Department of Mathematics and Computer Science, University of Bremen, Bremen, Germany
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Krivan SJ, Thomas NA. A Call for the Empirical Investigation of Tear Stimuli. Front Psychol 2020; 11:52. [PMID: 32082220 PMCID: PMC7005069 DOI: 10.3389/fpsyg.2020.00052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/09/2020] [Indexed: 11/21/2022] Open
Abstract
Emotional crying is a uniquely human behavior, which typically elicits helping and empathic responses from observers. However, tears can also be used to deceive. “Crocodile tears” are insincere tears used to manipulate the observer and foster prosocial responses. The ability to discriminate between genuine and fabricated emotional displays is critical to social functioning. When insincere emotional displays are detected, they are most often met with backlash. Conversely, genuine displays foster prosocial responses. However, the majority of crying research conducted to date has used posed stimuli featuring artificial tears. As such it is yet to be determined how the artificial nature of these displays impacts person perception. Throughout this article, we discuss the necessity for empirical investigation of the differences (or similarities) in responses to posed and genuine tearful expressions. We will explore the recent adoption of genuine stimuli in emotion research and review the existing research using tear stimuli. We conclude by offering suggestions and considerations for future advancement of the emotional crying field through investigation of both posed and genuine tear stimuli.
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Affiliation(s)
- Sarah J Krivan
- Department of Psychology, Applied Attention and Perceptual Processing Laboratory, College of Healthcare Sciences, James Cook University, Cairns, QLD, Australia.,Applied Attention and Perceptual Processing Laboratory, School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | - Nicole A Thomas
- Applied Attention and Perceptual Processing Laboratory, School of Psychological Sciences, Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
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Ito K, Ong CW, Kitada R. Emotional Tears Communicate Sadness but Not Excessive Emotions Without Other Contextual Knowledge. Front Psychol 2019; 10:878. [PMID: 31068868 PMCID: PMC6491854 DOI: 10.3389/fpsyg.2019.00878] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 04/03/2019] [Indexed: 12/17/2022] Open
Abstract
Contexts of face perception are diverse. They range from the social environment to body postures, from the expresser’s gaze direction to the tone of voice. In extending the research on contexts of face perception, we investigated people’s perception of tears on a face. The act of shedding tears is often perceived as an expression of sad feelings aroused by experiencing loss, disappointment, or helplessness. Alternatively, tears may also represent the excessive intensity of any emotion, such as extreme fear during an unexpected encounter with a giant bear and extreme happiness when you win a competition. Investigating these competing interpretations of tears, we found that the addition of tears to different facial expressions made the expressions conceptually closer to sad expressions. In particular, the results of the similarity analysis showed that, after the addition of tears, patterns of ratings for anger, fear, disgust, and neutral facial expressions became more similar to those for sadness expressions. The effect of tears on the ratings of basic emotions and their patterns in facial expressions are discussed.
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Affiliation(s)
- Kenichi Ito
- Division of Psychology, School of Social Sciences, College of Humanities, Arts, and Social Sciences, Nanyang Technological University, Singapore, Singapore
| | - Chew Wei Ong
- Division of Psychology, School of Social Sciences, College of Humanities, Arts, and Social Sciences, Nanyang Technological University, Singapore, Singapore
| | - Ryo Kitada
- Division of Psychology, School of Social Sciences, College of Humanities, Arts, and Social Sciences, Nanyang Technological University, Singapore, Singapore
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Brudzynski SM. Emission of 22 kHz vocalizations in rats as an evolutionary equivalent of human crying: Relationship to depression. Behav Brain Res 2019; 363:1-12. [PMID: 30677449 DOI: 10.1016/j.bbr.2019.01.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 02/08/2023]
Abstract
There is no clear relationship between crying and depression based on human neuropsychiatric observations. This situation originates from lack of suitable animal models of human crying. In the present article, an attempt will be made to answer the question whether emission of rat aversive vocalizations (22 kHz calls) may be regarded as an evolutionary equivalent of adult human crying. Using this comparison, the symptom of crying in depressed human patients will be reanalyzed. Numerous features and characteristics of rat 22 kHz aversive vocalizations and human crying vocalizations are equivalent. Comparing evolutionary, biological, physiological, neurophysiological, social, pharmacological, and pathological aspects have shown vast majority of common features. It is concluded that emission of rat 22 kHz vocalizations may be treated as an evolutionary vocal homolog of human crying, although emission of 22 kHz calls is not exactly the same phenomenon because of significant differences in cognitive processes between these species. It is further concluded that rat 22 kHz vocalizations and human crying vocalizations are both expressing anxiety and not depression. Analysis of the relationship between anxiety and depression reported in clinical studies supports this conclusion regardless of the nature and extent of comorbidity between these pathological states.
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Affiliation(s)
- Stefan M Brudzynski
- Department of Psychology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
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