1
|
Gainotti G. Mainly Visual Aspects of Emotional Laterality in Cognitively Developed and Highly Social Mammals-A Systematic Review. Brain Sci 2024; 14:52. [PMID: 38248267 PMCID: PMC10813540 DOI: 10.3390/brainsci14010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/19/2023] [Accepted: 12/29/2023] [Indexed: 01/23/2024] Open
Abstract
Several studies have shown that emotions are asymmetrically represented in the human brain and have proposed three main models (the 'right hemisphere hypothesis', the 'approach-withdrawal hypothesis' and the 'valence hypothesis') that give different accounts of this emotional laterality. Furthermore, in recent years, many investigations have suggested that a similar emotional laterality may also exist in different animal taxa. However, results of a previous systematic review of emotional laterality in non-human primates have shown that some of these studies might be criticized from the methodological point of view and support only in part the hypothesis of a continuum in emotional laterality across vertebrates. The aim of the present review therefore consisted in trying to expand this survey to other cognitively developed and highly social mammals, focusing attention on mainly visual aspects of emotional laterality, in studies conducted on the animal categories of horses, elephants, dolphins and whales. The 35 studies included in the review took into account three aspects of mainly visual emotional laterality, namely: (a) visual asymmetries for positive/familiar vs. negative/novel stimuli; (b) lateral position preference in mother-offspring or other affiliative interactions; (c) lateral position preference in antagonistic interactions. In agreement with data obtained from human studies that have evaluated comprehension or expression of emotions at the facial or vocal level, these results suggest that a general but graded right-hemisphere prevalence in the processing of emotions can be found at the visual level in cognitively developed non-primate social mammals. Some methodological problems and some implications of these results for human psychopathology are briefly discussed.
Collapse
Affiliation(s)
- Guido Gainotti
- Institute of Neurology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy; ; Tel.: +39-06-30156435
- Fondazione Policlinico A. Gemelli, IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), 00168 Rome, Italy
| |
Collapse
|
2
|
Tomonaga M, Uwano-Ito Y, Saito T, Sakurai N. Left or right, that is the question: use of egocentric frame of reference and the right-eye advantage for understanding gestural signs in bottlenose dolphins (Tursiops truncatus). Anim Cogn 2023; 26:1551-1569. [PMID: 37318674 DOI: 10.1007/s10071-023-01799-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023]
Abstract
How do bottlenose dolphins visually perceive the space around them? In particular, what cues do they use as a frame of reference for left-right perception? To address this question, we examined the dolphin's responses to various manipulations of the spatial relationship between the dolphin and the trainer by using gestural signs for actions given by the trainer, which have different meanings in the left and right hands. When the dolphins were tested with their backs to the trainer (Experiment 1) or in an inverted position underwater (Experiments 2 and 3), correct responses from the trainer's perspective were maintained for signs related to movement direction instructions. In contrast, reversed responses were frequently observed for signs that required different sounds for the left and right hands. When the movement direction instructions were presented with symmetrical graphic signs such as " × " and "●", accuracy decreased in the inverted posture (Experiment 3). Furthermore, when the signs for sounds were presented from either the left or right side of the dolphin's body, performance was better when the side of the sign movement coincided with the body side on which it was presented than when it was mismatched (Experiment 4). In the final experiment, when one eye was covered with an eyecup, the results showed that, as in the case of body-side presentation, performance was better when the open eye coincided with the side on which the sign movement was presented. These results indicate that dolphins used the egocentric frame for visuospatial cognition. In addition, they showed better performances when the gestural signs were presented to the right eye, suggesting the possibility of a left-hemispheric advantage in the dolphin's visuospatial cognition.
Collapse
Affiliation(s)
- Masaki Tomonaga
- University of Human Environments, Matsuyama, Ehime, 790-0825, Japan.
- Japan Monkey Centre, Inuyama, Aichi, 484-0081, Japan.
| | - Yuka Uwano-Ito
- Port of Nagoya Public Aquarium, Nagoya, Aichi, 455-0033, Japan
| | - Toyoshi Saito
- Port of Nagoya Public Aquarium, Nagoya, Aichi, 455-0033, Japan
| | - Natsuko Sakurai
- Minamichita Beachland Aquarium, Mihama, Aichi, 470-3233, Japan
| |
Collapse
|
3
|
Hill HMM, Guarino S, Yeater D, White C, Kolodziej K, Ali SNS, Lamia S, Garcia E, Dear M, Halter ER, Bradley M. Cetacean responses to violation of expectation paradigm in a free-swim context. Anim Cogn 2023; 26:667-686. [PMID: 36333497 DOI: 10.1007/s10071-022-01704-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/08/2022]
Abstract
The investigation of individual responses to unexpected stimuli or outcomes provides insights into basic cognitive processes, such as mental representations, emotional states of surprise, and detections of anomalies. Three experiments using a violation of expectation paradigm were conducted with 12 belugas and 17 bottlenose dolphins in managed care to test two classes of stimuli (humans and objects) in manipulated sequences of familiar and unfamiliar humans (Study 1, trainers and strangers), familiar and unfamiliar objects (Study 2, typical enrichment devices and new objects), and finally objects and humans (Study 3). Gaze durations were assessed for each condition in a given study during free-swim contexts. The results supported previous findings that visual stimuli, regardless of class, were stimulating and intriguing for both belugas and bottlenose dolphins. Belugas were more likely to gaze longer at human and object stimuli and tended to gaze longer at unexpected experiences than control or expected experiences. Bottlenose dolphins showed similar trends except when objects were involved. Individual variability was present for both species with some individuals showing stronger patterns of responses for expected experiences than others. After 2 years of intermittent experiments, belugas and bottlenose dolphins in managed care maintained their curiosity about visual stimuli, for which they received no primary reinforcement. Investigating responses to unexpected stimuli with animals in managed care may provide insight into how these animals respond to biologically relevant conditions, such as boat presence, predators, and unfamiliar conspecifics.
Collapse
Affiliation(s)
- Heather M Manitzas Hill
- Psychology Department, St. Mary's University, One Camino Santa Maria, San Antonio, TX, 78228, USA.
| | - Sara Guarino
- Psychology Department, St. Mary's University, One Camino Santa Maria, San Antonio, TX, 78228, USA
| | | | - Chris White
- SeaWorld of Texas, SeaWorld Parks, Inc, San Diego, USA
| | | | | | | | - Emily Garcia
- Psychology Department, St. Mary's University, One Camino Santa Maria, San Antonio, TX, 78228, USA
| | - Megan Dear
- Mt. Holyoke College, South Hadley, MA, USA
| | | | | |
Collapse
|
4
|
Henaut Y, Charles A, Delfour F. Cognition of the manatee: past research and future developments. Anim Cogn 2022; 25:1049-1058. [PMID: 36002602 DOI: 10.1007/s10071-022-01676-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/31/2022] [Accepted: 08/08/2022] [Indexed: 11/26/2022]
Abstract
In this paper, we present a review of the current knowledge related to the cognitive abilities of the manatee, with a focus on the Antillean manatee in situ and ex situ. Following a biocentric approach, we consider the animals' ecology, perception and sociality and we introduce future perspectives on their cognition. Scientific literature on the cognitive abilities of Antillean manatees' is limited and mainly linked to medical training and veterinary manipulations. To perceive and to interact with their social and natural environment (e.g. social interactions, foraging and traveling), manatees use visual, acoustic and tactile modalities that may be involved in a large range of cognitive abilities. Research on stimuli perception in manatees is scarce; however, these animals demonstrate abilities to learn and appear to show long-term memory. For example, to mate and/or to forage manatees travel at medium and large geographical scales; without doubt their movements entail the use of a set of stimuli and learning processes. Furthermore, their social skills (e.g. social organization, tactile and acoustic communications) are also poorly understood although their social interactions appear to be more complex than previously thought. Finally, as for many animals, temperament/personality may play a key role during their interactions with conspecifics and the environment. These aspects on manatee behavior and cognition are important for management and conservation purposes and help us understand the evolution of these marine mammals.
Collapse
Affiliation(s)
- Yann Henaut
- Laboratorio de Conducta Animal, GAIA-BIO, El Colegio de la Frontera Sur (ECOSUR), Av. del Centenario Km. 5.5, C.P. 77014, Chetumal, Quintana Roo, Mexico.
| | - Aviva Charles
- Centre d'Ecologie et des Sciences de la Conservation (CESCO, UMR 7204, CNRS, MNHN, Sorbonne-Université, MNHN), Paris, France
- ZooParc de Beauval and Beauval Nature, 41110, Saint Aignan, France
| | | |
Collapse
|
5
|
Charles A, Mercera B, Delfour F. Bottlenose dolphins' (Tursiops Truncatus) visual and motor laterality depending on emotional contexts. Behav Processes 2021; 187:104374. [PMID: 33741435 DOI: 10.1016/j.beproc.2021.104374] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 12/24/2022]
Abstract
Hemispheric lateralization is a specialized neural and cognitive processing achieved preferentially by either the left or the right hemisphere of the brain. Among vertebrates, emotions processing seems to be lateralized, but the involvement of each hemisphere is still on debate. Our study investigated visual and motor laterality on five bottlenose dolphins' (Tursiops truncatus) during spontaneous and experimentally induced emotional contexts. We measured motor laterality in pectoral used and swimming position during positive social interactions. Additionally, during training sessions, stimuli with positive or negative emotional valences were presented either on the dolphins' left or right side. Emotional reactions toward stimuli were measured and a visual laterality index was calculated. Dolphins were visually left-lateralized during training sessions. They also reacted more when negative stimuli were presented on their left side than right side during the first stimuli presentation. Our results suggest that bottlenose dolphins, like other vertebrates, may present a right hemisphere dominance for social information processing, detection of and response to unpredictable or novel stimuli and a left-hemisphere dominance during escape responses inhibition. Further studies on a larger sample size should explore inter-individual variation and identify other potential contexts in which lateralization emerges. Emotional lateralization should be considered as a potential indicator for future dolphin welfare assessment.
Collapse
Affiliation(s)
| | | | - Fabienne Delfour
- Parc Asterix, 60128 Plailly, France; Laboratoire d'Ethologie Expérimentale et Comparée, Université Paris 13, 93430 Villetaneuse, France
| |
Collapse
|
6
|
Jaakkola K, Loyer C, Guarino E, Donegan K, McMullen C. Do dolphins really have a rightward lateralization for action? The importance of behavior-specific and orientation-neutral coding. Behav Brain Res 2020; 401:113083. [PMID: 33358918 DOI: 10.1016/j.bbr.2020.113083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 11/25/2022]
Abstract
Because each side of the vertebrate body is controlled by a different side of the brain, studies of behavioral lateralization can provide insight into functional cerebral asymmetries in humans and other animals. The current study examined behavioral lateralization for a variety of behaviors in a group of 26 dolphins, in order to assess the claim that cetaceans show strong rightward action asymmetries indicative of a left-hemisphere specialization for action. We distinguished between side asymmetries and whole body turning actions, and devised a new coding system to counter the problem that previous studies of rolling behaviors (i.e., rotations around the long axis) have used contradictory coding systems depending on species' typical orientation. Our results did not support a generalized population-level rightward action asymmetry across multiple behaviors. Instead, we suggest that many dolphin behavioral asymmetries may be better explained as a result of perceptual processing asymmetries common across many vertebrates.
Collapse
Affiliation(s)
- Kelly Jaakkola
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL, 33050, USA.
| | - Carolyn Loyer
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL, 33050, USA
| | - Emily Guarino
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL, 33050, USA
| | - Katy Donegan
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL, 33050, USA
| | - Christina McMullen
- Dolphin Research Center, 58901 Overseas Highway, Grassy Key, FL, 33050, USA
| |
Collapse
|
7
|
Shen J, Fang K, Liu P, Fan Y, Yang J, Shen D, Song J, Fang G. Low-frequency electroencephalogram oscillations govern left-eye lateralization during anti-predatory responses in the music frog. J Exp Biol 2020; 223:jeb232637. [PMID: 32967996 DOI: 10.1242/jeb.232637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/15/2020] [Indexed: 11/20/2022]
Abstract
Visual lateralization is widespread for prey and anti-predation in numerous taxa. However, it is still unknown how the brain governs this asymmetry. In this study, we conducted behavioral and electrophysiological experiments to evaluate anti-predatory behaviors and dynamic brain activities in Emei music frogs (Nidirana daunchina), to explore the potential eye bias for anti-predation and the underlying neural mechanisms. To do this, predator stimuli (a model snake head and a leaf as a control) were moved around the subjects in clockwise and anti-clockwise directions at steady velocity. We counted the number of anti-predatory responses and measured electroencephalogram (EEG) power spectra for each band and brain area (telencephalon, diencephalon and mesencephalon). Our results showed that (1) no significant eye preferences could be found for the control (leaf); however, the laterality index was significantly lower than zero when the predator stimulus was moved anti-clockwise, suggesting that left-eye advantage exists in this species for anti-predation; (2) compared with no stimulus in the visual field, the power spectra of delta and alpha bands were significantly greater when the predator stimulus was moved into the left visual field anti-clockwise; and, (3) generally, the power spectra of each band in the right-hemisphere for the left visual field were higher than those in the left counterpart. These results support that the left eye mediates the monitoring of a predator in music frogs and lower-frequency EEG oscillations govern this visual lateralization.
Collapse
Affiliation(s)
- Jiangyan Shen
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, No. 1 Shi Da Road, Nanchong, 637009 Sichuan, China
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| | - Ke Fang
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
| | - Ping Liu
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| | - Yanzhu Fan
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| | - Jing Yang
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| | - Di Shen
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| | - Jinjin Song
- School of Life Science, Anhui University, Hefei, 230601 Anhui, China
| | - Guangzhan Fang
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, No. 1 Shi Da Road, Nanchong, 637009 Sichuan, China
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041 Sichuan, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, 100049 Beijing, China
| |
Collapse
|
8
|
Shen J, Fang K, Fan Y, Song J, Yang J, Shen D, Liu Y, Fang G. Dynamics of electroencephalogram oscillations underlie right-eye preferences in predatory behavior of the music frog. ACTA ACUST UNITED AC 2019; 222:jeb.212175. [PMID: 31611293 DOI: 10.1242/jeb.212175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/07/2019] [Indexed: 12/15/2022]
Abstract
Visual lateralization is a typical characteristic of many vertebrates; however, its underlying dynamic neural mechanism is unclear. In this study, predatory responses and dynamic brain activities were evaluated in the Emei music frog (Nidirana daunchina) to assess the potential eye preferences and their underlying dynamic neural mechanism, using behavioral and electrophysiological experiments, respectively. To do this, when the prey stimulus (live cricket and leaf as control) was moved around the frogs in both clockwise and anticlockwise directions at constant velocity, the number of predatory responses were counted and electroencephalogram (EEG) absolute power spectra for each band were measured for the telencephalon, diencephalon and mesencephalon. The results showed that: (1) no significant differences in the number of predatory responses could be found for the control (leaf), but the number of predatory responses for the right visual field (RVF) was significantly greater than that for the left visual field (LVF) when the live cricket was moved into the RVF clockwise; (2) compared with no stimulus in the visual field and stimulus in the LVF, the power spectra of each EEG band were greater when the prey stimulus was moved into the RVF clockwise; and (3) the power spectra of the theta, alpha and beta bands in the left diencephalon were significantly greater than those of the right counterpart for the clockwise direction, but similar significant differences presented for the delta, theta and alpha bands in the anticlockwise direction. Together, the results suggested that right-eye preferences for predatory behaviors exist in music frogs, and that the dynamics of EEG oscillations might underlie this right eye/left hemisphere advantage.
Collapse
Affiliation(s)
- Jiangyan Shen
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, People's Republic of China
| | - Ke Fang
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China
| | - Yanzhu Fan
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, People's Republic of China
| | - Jinjin Song
- School of Life Science, Anhui University, Hefei, Anhui, People's Republic of China
| | - Jing Yang
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, People's Republic of China
| | - Di Shen
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing, People's Republic of China
| | - Yansu Liu
- Sichuan Nursing Vocational College, No. 173, Longdu Nan Road, Longquan District, Chengdu, Sichuan, People's Republic of China
| | - Guangzhan Fang
- Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, People's Republic of China
| |
Collapse
|
9
|
d'Ingeo S, Quaranta A, Siniscalchi M, Stomp M, Coste C, Bagnard C, Hausberger M, Cousillas H. Horses associate individual human voices with the valence of past interactions: a behavioural and electrophysiological study. Sci Rep 2019; 9:11568. [PMID: 31399629 PMCID: PMC6689011 DOI: 10.1038/s41598-019-47960-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/16/2019] [Indexed: 11/27/2022] Open
Abstract
Brain lateralization is a phenomenon widely reported in the animal kingdom and sensory laterality has been shown to be an indicator of the appraisal of the stimulus valence by an individual. This can prove a useful tool to investigate how animals perceive intra- or hetero-specific signals. The human-animal relationship provides an interesting framework for testing the impact of the valence of interactions on emotional memories. In the present study, we tested whether horses could associate individual human voices with past positive or negative experiences. Both behavioural and electroencephalographic measures allowed examining laterality patterns in addition to the behavioural reactions. The results show that horses reacted to voices associated with past positive experiences with increased attention/arousal (gamma oscillations in the right hemisphere) and indicators of a positive emotional state (left hemisphere activation and ears held forward), and to those associated with past negative experiences with negative affective states (right hemisphere activation and ears held backwards). The responses were further influenced by the animals’ management conditions (e.g. box or pasture). Overall, these results, associating brain and behaviour analysis, clearly demonstrate that horses’ representation of human voices is modulated by the valence of prior horse-human interactions.
Collapse
Affiliation(s)
- Serenella d'Ingeo
- Department of Veterinary Medicine, Section of Animal Physiology and Behaviour, University of Bari "Aldo Moro", Bari, Italy. .,Université de Rennes, UMR 6552 -Laboratoire Ethologie Animale et Humaine-EthoS-, CNRS, Université de Caen-Normandie, Station Biologique, 35380, Paimpont, France.
| | - Angelo Quaranta
- Department of Veterinary Medicine, Section of Animal Physiology and Behaviour, University of Bari "Aldo Moro", Bari, Italy
| | - Marcello Siniscalchi
- Department of Veterinary Medicine, Section of Animal Physiology and Behaviour, University of Bari "Aldo Moro", Bari, Italy
| | - Mathilde Stomp
- Université de Rennes, UMR 6552 -Laboratoire Ethologie Animale et Humaine-EthoS-, CNRS, Université de Caen-Normandie, Station Biologique, 35380, Paimpont, France
| | - Caroline Coste
- Université de Rennes, UMR 6552 -Laboratoire Ethologie Animale et Humaine-EthoS-, CNRS, Université de Caen-Normandie, Station Biologique, 35380, Paimpont, France
| | - Charlotte Bagnard
- Université de Rennes, UMR 6552 -Laboratoire Ethologie Animale et Humaine-EthoS-, CNRS, Université de Caen-Normandie, Station Biologique, 35380, Paimpont, France
| | - Martine Hausberger
- CNRS- UMR 6552, - Laboratoire Ethologie Animale et Humaine-EthoS-, Université de Rennes, Université de Caen-Normandie, 263 avenue du Général Leclerc, 35042, Rennes, Cedex, France
| | - Hugo Cousillas
- Université de Rennes, UMR CNRS 6552 -Laboratoire Ethologie Animale et Humaine-EthoS- CNRS, Université de Caen-Normandie, Campus de Beaulieu, 263 avenue du général Leclerc, 35042, Rennes, cedex, France
| |
Collapse
|
10
|
Matrai E, Hoffmann-Kuhnt M, Kwok ST. Lateralization in accuracy, reaction time and behavioral processes in a visual discrimination task in an Indo-Pacific bottlenose dolphin (Tursiops aduncus). Behav Processes 2019; 162:112-118. [PMID: 30779941 DOI: 10.1016/j.beproc.2019.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/26/2019] [Accepted: 02/11/2019] [Indexed: 11/15/2022]
Abstract
Perceptual and behavioral asymmetry has been observed in a wide range of vertebrate and invertebrate species with its origin estimated to go back over 500 million years. Previously, hemispheric lateralization in marine mammals has been recorded during foraging, parental care, preferred swimming direction as well as when solving cognitive challenges. Visual laterality has been demonstrated in preferred eye use and performance accuracy. A female Indo-Pacific bottlenose dolphin was trained to associate eight pairs of non-identical visual stimuli. Her performance was tested and compared under binocular and monocular conditions. No significant difference was found in accuracy, while a clear left eye advantage was demonstrated in reaction time. In addition, behavioral asymmetry was observed in movement pattern preference during the stimulus discrimination.
Collapse
Affiliation(s)
- Eszter Matrai
- Ocean Park, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong.
| | - Matthias Hoffmann-Kuhnt
- Acoustic Research Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore.
| | - Shaw Ting Kwok
- Ocean Park, 180 Wong Chuk Hang Road, Aberdeen, Hong Kong.
| |
Collapse
|
11
|
Leroux M, Hetem RS, Hausberger M, Lemasson A. Cheetahs discriminate familiar and unfamiliar human voices. Sci Rep 2018; 8:15516. [PMID: 30341369 PMCID: PMC6195546 DOI: 10.1038/s41598-018-33971-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/09/2018] [Indexed: 11/08/2022] Open
Abstract
Domestic species can make the distinction between several human sub-groups, especially between familiar and unfamiliar persons. The Domestication hypothesis assumes that such advanced cognitive skills were driven by domestication itself. However, such capacities have been shown in wild species as well, highlighting the potential role of early experience and proximity with humans. Nevertheless, few studies have been focusing on the use of acoustic cues in wild species and more comparative studies are necessary to better understand this ability. Cheetah is a vocal, semi-social species, often hand raised when captive, making it therefore a good candidate for studying the ability to perceive differences in human voices. In this study, we used playback experiments to investigate whether cheetahs are able to distinguish between the voices of their familiar caretakers and visitors. We found that cheetahs showed a higher visual attention, changed activity more often and faster when the voice was familiar than when it was unfamiliar. This study is the first evidence that wild felids are able to discriminate human voices and could support the idea that early experience and proximity to humans are at least as important as domestication when it comes to the ability to recognize humans.
Collapse
Affiliation(s)
- Maël Leroux
- Univ Rennes, Normandie Univ, CNRS, EthoS (Éthologie animale et humaine) - UMR 6552, Paimpont, F-35380, France
| | - Robyn Shelia Hetem
- University of the Witwatersrand, School of Animal, Plant and Environmental Sciences, 1 Jan Smuts Avenue, Braamfontein, 2000, South Africa
| | - Martine Hausberger
- CNRS, Univ Rennes, Normandie Univ, EthoS (Éthologie animale et humaine) - UMR 6552, F-35380, Paimpont, France
| | - Alban Lemasson
- Univ Rennes, Normandie Univ, CNRS, EthoS (Éthologie animale et humaine) - UMR 6552, Paimpont, F-35380, France.
| |
Collapse
|
12
|
Winship KA, Eskelinen HC. Behavioral responses of two species of dolphins to novel video footage: An exploration of sex differences. Zoo Biol 2018; 37:399-407. [PMID: 30211954 DOI: 10.1002/zoo.21444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/19/2018] [Accepted: 08/28/2018] [Indexed: 11/08/2022]
Abstract
This study assessed the interest toward novel video clips as enrichment stimuli in two species of captive dolphins (Tursiops: n = 11; Steno: n = 5). Videos were played at underwater viewing windows while the animals were housed with conspecifics, and responses were subsequently analyzed based on general content of each novel video. Interest levels (i.e., percentage of time watching and behavioral rate) were compared between species and within species across video categories. While the varied video contexts did not produce significant differences among the time spent watching or behaviors observed, species differences and sex differences were noted. Rough-toothed dolphins displayed significantly more behaviors, particularly interest and bubble behaviors, than bottlenose dolphins, with no differences observed between the species for the percentage of time spent watching. Among bottlenose dolphins, males watched the television longer, and responded behaviorally significantly more, displaying a higher rate of bubble and aggressive behaviors than females. Male rough-toothed dolphins displayed significantly more aggressive behaviors than females, with no other sex differences noted. Overall, these data suggest that television may serve as a useful enrichment device for certain individuals and species of cetaceans, as well as a cognitive experimental tool, as long as sex, species, and individual differences are taken into consideration when interpreting results.
Collapse
Affiliation(s)
- Kelley A Winship
- Dolphins Plus Marine Mammal Responder, Key Largo, Florida.,Rosenstiel School for Marine and Atmospheric Science, Miami, Florida
| | - Holli C Eskelinen
- Dolphins Plus Marine Mammal Responder, Key Largo, Florida.,Rosenstiel School for Marine and Atmospheric Science, Miami, Florida
| |
Collapse
|
13
|
Wright AK, Theilmann RJ, Ridgway SH, Scadeng M. Diffusion tractography reveals pervasive asymmetry of cerebral white matter tracts in the bottlenose dolphin (Tursiops truncatus). Brain Struct Funct 2017; 223:1697-1711. [PMID: 29189908 PMCID: PMC5884918 DOI: 10.1007/s00429-017-1525-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 07/06/2017] [Indexed: 12/18/2022]
Abstract
Brain enlargement is associated with concomitant growth of interneuronal distance, increased conduction time, and reduced neuronal interconnectivity. Recognition of these functional constraints led to the hypothesis that large-brained mammals should exhibit greater structural and functional brain lateralization. As a taxon with the largest brains in the animal kingdom, Cetacea provides a unique opportunity to examine asymmetries of brain structure and function. In the present study, diffusion tensor imaging and tractography were used to investigate cerebral white matter asymmetry in the bottlenose dolphin (Tursiops truncatus). Widespread white matter asymmetries were observed with the preponderance of tracts exhibiting leftward structural asymmetries. Leftward lateralization may reflect differential processing and execution of behaviorally variant sensory and motor functions by the cerebral hemispheres. The arcuate fasciculus, an association tract linked to human language evolution, was isolated and exhibited rightward asymmetry suggesting a right hemisphere bias for conspecific communication unlike that of most mammals. This study represents the first examination of cetacean white matter asymmetry and constitutes an important step toward understanding potential drivers of structural asymmetry and its role in underpinning functional and behavioral lateralization in cetaceans.
Collapse
Affiliation(s)
- Alexandra K Wright
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA, 92093, USA.
| | - Rebecca J Theilmann
- Department of Radiology, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Sam H Ridgway
- National Marine Mammal Foundation, San Diego, CA, 92106, USA
| | - Miriam Scadeng
- Center for Functional MRI, Department of Radiology, University of California-San Diego, La Jolla, CA, 92093, USA
| |
Collapse
|
14
|
Spontaneous approaches of divers by free-ranging orcas (Orcinus orca): age- and sex-differences in exploratory behaviours and visual laterality. Sci Rep 2017; 7:10922. [PMID: 28883537 PMCID: PMC5589820 DOI: 10.1038/s41598-017-11488-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/25/2017] [Indexed: 11/08/2022] Open
Abstract
Running comparative studies of laterality in mammals is a way to deepen our understanding of the evolution of the brain hemisphere functions. Studies on vision highlighted a possible task-sharing between hemispheres depending on the characteristics of the observers, the nature of the observed stimulus and the context of the observation, a phenomenon that could go beyond the monitoring of conspecifics. Cetaceans are predators that adapted to an aquatic habitat and display a clear crossing of fibers to the side of the brain opposite the eye of origin. Here, we analysed the interactions between humans and cetaceans when free-ranging orcas approach divers. Our study concentrated on the spontaneous exploratory behaviours of divers by orcas depending on their age and sex, and on the possible expression of a visual laterality. The results showed a significant preference for the use of the left eye but exclusively in adult females. Adult males had a more sustained attention than adult females, marked by a higher spatial proximity to divers, slower approaches and longer look durations. Adult females, probably more cautious, explored from the distance and more furtively. Our findings support a possible link between attentional/motivational states and visual laterality in mammals.
Collapse
|
15
|
Learning to play: A review and theoretical investigation of the developmental mechanisms and functions of cetacean play. Learn Behav 2017; 45:335-354. [DOI: 10.3758/s13420-017-0291-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Platto S, Zhang C, Pine MK, Feng W, Yang L, Irwin A, Wang D. Behavioral laterality in Yangtze finless porpoises ( Neophocaena asiaeorientalis asiaeorientalis ). Behav Processes 2017; 140:104-114. [DOI: 10.1016/j.beproc.2017.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 04/23/2017] [Accepted: 04/24/2017] [Indexed: 11/25/2022]
|
17
|
Responses to familiar and unfamiliar objects by belugas (Delphinapterus leucas), bottlenose dolphins (Tursiops truncatus), and Pacific white-sided dolphins (Lagenorhynchus obliquidens). Anim Cogn 2017; 20:823-827. [PMID: 28600681 DOI: 10.1007/s10071-017-1103-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 05/19/2017] [Accepted: 06/02/2017] [Indexed: 10/19/2022]
Abstract
Previous research with bottlenose dolphins (Tursiops truncatus) demonstrated their ability to discriminate between familiar and unfamiliar stimuli. Dolphins gazed longer at unfamiliar stimuli. The current study attempted to extend this original research by examining the responses of three species of cetaceans to objects that differed in familiarity. Eleven belugas from two facilities, five bottlenose dolphins and five Pacific white-sided dolphins housed at one facility were presented different objects in a free-swim scenario. The results indicated that the animals gazed the longest at unfamiliar objects, but these gaze durations did not significantly differ from gaze durations when viewing familiar objects. Rather, the animals gazed longer at unfamiliar objects when compared to the apparatus alone. Species differences emerged with longer gaze durations exhibited by belugas and bottlenose dolphins and significantly shorter gaze durations for Pacific white-sided dolphins. It is likely that the animals categorized objects into familiar and unfamiliar categories, but the free-swim paradigm in naturalistic social groupings did not elicit clear responses. Rather this procedure emphasized the importance of attention and individual preferences when investigating familiar and unfamiliar objects, which has implications for cognitive research and enrichment use.
Collapse
|
18
|
Kremers D, Célérier A, Schaal B, Campagna S, Trabalon M, Böye M, Hausberger M, Lemasson A. Sensory Perception in Cetaceans: Part I—Current Knowledge about Dolphin Senses As a Representative Species. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
19
|
Barber ALA, Randi D, Müller CA, Huber L. The Processing of Human Emotional Faces by Pet and Lab Dogs: Evidence for Lateralization and Experience Effects. PLoS One 2016; 11:e0152393. [PMID: 27074009 PMCID: PMC4830442 DOI: 10.1371/journal.pone.0152393] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/14/2016] [Indexed: 11/19/2022] Open
Abstract
From all non-human animals dogs are very likely the best decoders of human behavior. In addition to a high sensitivity to human attentive status and to ostensive cues, they are able to distinguish between individual human faces and even between human facial expressions. However, so far little is known about how they process human faces and to what extent this is influenced by experience. Here we present an eye-tracking study with dogs emanating from two different living environments and varying experience with humans: pet and lab dogs. The dogs were shown pictures of familiar and unfamiliar human faces expressing four different emotions. The results, extracted from several different eye-tracking measurements, revealed pronounced differences in the face processing of pet and lab dogs, thus indicating an influence of the amount of exposure to humans. In addition, there was some evidence for the influences of both, the familiarity and the emotional expression of the face, and strong evidence for a left gaze bias. These findings, together with recent evidence for the dog's ability to discriminate human facial expressions, indicate that dogs are sensitive to some emotions expressed in human faces.
Collapse
Affiliation(s)
- Anjuli L. A. Barber
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria
- * E-mail:
| | - Dania Randi
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria
| | - Corsin A. Müller
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria
| | - Ludwig Huber
- Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria
| |
Collapse
|
20
|
Tomonaga M, Uwano Y, Ogura S, Chin H, Dozaki M, Saito T. Which person is my trainer? Spontaneous visual discrimination of human individuals by bottlenose dolphins (Tursiops truncatus). SPRINGERPLUS 2015; 4:352. [PMID: 26191479 PMCID: PMC4502054 DOI: 10.1186/s40064-015-1147-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 07/08/2015] [Indexed: 11/30/2022]
Abstract
Bottlenose dolphins are known to use signature whistles to identify conspecifics auditorily. However, the way in which they recognize individuals visually is less well known. We investigated their visual recognition of familiar human individuals under the spontaneous discrimination task. In each trial, the main trainer appeared from behind a panel. In test trials, two persons (one was the main trainer) appeared from the left and right sides of the panel and moved along the poolside in opposite directions. Three of the four dolphins spontaneously followed their main trainers significantly above the level of chance. Subsequent tests, however, revealed that when the two persons wore identical clothing, the following response deteriorated. This suggests that dolphins can spontaneously discriminate human individuals using visual cues, but they do not utilize facial cues, but body area for this discrimination.
Collapse
Affiliation(s)
- Masaki Tomonaga
- Primate Research Institute, Kyoto University, Kanrin 41-2, Inuyama, Aichi 484-8506 Japan
| | - Yuka Uwano
- Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan
| | - Sato Ogura
- Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan
| | - Hyangsun Chin
- Graduate School of Humanities, Kwansei-Gakuin University, Uegahara, Nishinomiya, Hyogo 662-8501 Japan
| | - Masahiro Dozaki
- Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan
| | - Toyoshi Saito
- Port of Nagoya Public Aqualium, Minato-machi 1-3, Minato, Nagoya, Aichi 455-0033 Japan
| |
Collapse
|
21
|
Winters S, Dubuc C, Higham JP. Perspectives: The Looking Time Experimental Paradigm in Studies of Animal Visual Perception and Cognition. Ethology 2015. [DOI: 10.1111/eth.12378] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sandra Winters
- Department of Anthropology; New York University; New York NY USA
| | - Constance Dubuc
- Department of Anthropology; New York University; New York NY USA
| | - James P. Higham
- Department of Anthropology; New York University; New York NY USA
| |
Collapse
|
22
|
Visual laterality in belugas (Delphinapterus leucas) and Pacific white-sided dolphins (Lagenorhynchus obliquidens) when viewing familiar and unfamiliar humans. Anim Cogn 2014; 17:1245-59. [DOI: 10.1007/s10071-014-0756-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 05/06/2014] [Indexed: 10/25/2022]
|
23
|
MacNeilage PF. Vertebrate whole-body-action asymmetries and the evolution of right handedness: A comparison between humans and marine mammals. Dev Psychobiol 2013; 55:577-87. [DOI: 10.1002/dev.21114] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/12/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Peter F. MacNeilage
- Professor Emeritus of Psychology; University of Texas at Austin; 606 Harthan St., Austin, TX; 78712
| |
Collapse
|
24
|
Social laterality in wild beluga whale infants: comparisons between locations, escort conditions, and ages. Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1545-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
25
|
Braccini SN, Lambeth SP, Schapiro SJ, Fitch WT. Eye preferences in captive chimpanzees. Anim Cogn 2012; 15:971-8. [PMID: 22733385 PMCID: PMC3823526 DOI: 10.1007/s10071-012-0523-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 11/30/2022]
Abstract
Over the last century, the issue of brain lateralization in primates has been extensively investigated and debated, yet no previous study has reported eye preference in great apes. This study examined eye preference in 45 captive chimpanzees (Pan troglodytes) in response to various stimuli. Eye preference was assessed when animals looked through a hole that only accommodated one eye at an empty box, a mirror, a picture of a dog, a rubber snake, food biscuits, bananas, a rubber duck, and a video camera. Main effects of stimulus type were found for direction of eye preference, number of looks, and looking duration, but not for strength of eye preference. A left-eye bias was found for viewing the rubber snake and a right-eye bias was found for viewing the bananas, supporting theories that emotional valence may affect lateralized behaviors. In addition, a significant shift in eye preference took place from the initial look to subsequent looks when viewing the snake. These results are not consistent with previous reports of human eye preference and may reflect lateralization differences for emotional processing. No relationship between eye preference and previously recorded hand preference was found.
Collapse
Affiliation(s)
- Stephanie N. Braccini
- Centre for Social Learning and Cognitive Evolution and Scottish Primate Research Group, School of Psychology, University of St Andrews, St Andrews KY16 9JP, UK. Saint Louis Zoo, One Government Drive, St Louis, MO 63110, USA
| | - Susan P. Lambeth
- Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Steven J. Schapiro
- Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA. Department of Experimental Medicine, University of Copenhagen, Copenhagen, Denmark
| | - W. Tecumseh Fitch
- Department of Cognitive Biology, School of Life Sciences, University of Vienna, 14 Althanstrasse, Vienna, Austria. School of Psychology, University of St Andrews, St Andrews KY16 9JP, UK
| |
Collapse
|
26
|
Siniscalchi M, Dimatteo S, Pepe AM, Sasso R, Quaranta A. Visual lateralization in wild striped dolphins (Stenella coeruleoalba) in response to stimuli with different degrees of familiarity. PLoS One 2012; 7:e30001. [PMID: 22253855 PMCID: PMC3258257 DOI: 10.1371/journal.pone.0030001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 12/08/2011] [Indexed: 11/18/2022] Open
Abstract
Background Apart from findings on both functional and motor asymmetries in captive aquatic mammals, only few studies have focused on lateralized behaviour of these species in the wild. Methodology/Principal Findings In this study we focused on lateralized visual behaviour by presenting wild striped dolphins with objects of different degrees of familiarity (fish, ball, toy). Surveys were conducted in the Gulf of Taranto, the northern Ionian Sea portion delimited by the Italian regions of Calabria, Basilicata and Apulia. After sighting striped dolphins from a research vessel, different stimuli were presented in a random order by a telescopic bar connected to the prow of the boat. The preferential use of the right/left monocular viewing during inspection of the stimuli was analysed. Conclusion Results clearly showed a monocular viewing preference with respect to the type of the stimulus employed. Due to the complete decussation of the optical nerves in dolphin brain our results reflected a different specialization of brain hemispheres for visual scanning processes confirming that in this species different stimuli evoked different patterns of eye use. A preferential use of the right eye (left hemisphere) during visual inspection of unfamiliar targets was observed supporting the hypothesis that, in dolphins, the organization of the functional neural structures which reflected cerebral asymmetries for visual object recognition could have been subjected to a deviation from the evolutionary line of most terrestrial vertebrates.
Collapse
|
27
|
Blois-Heulin C, Crével M, Böye M, Lemasson A. Visual laterality in dolphins: importance of the familiarity of stimuli. BMC Neurosci 2012; 13:9. [PMID: 22239860 PMCID: PMC3277460 DOI: 10.1186/1471-2202-13-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 01/12/2012] [Indexed: 11/17/2022] Open
Abstract
Background Many studies of cerebral asymmetries in different species lead, on the one hand, to a better understanding of the functions of each cerebral hemisphere and, on the other hand, to develop an evolutionary history of hemispheric laterality. Our animal model is particularly interesting because of its original evolutionary path, i.e. return to aquatic life after a terrestrial phase. The rare reports concerning visual laterality of marine mammals investigated mainly discrimination processes. As dolphins are migrant species they are confronted to a changing environment. Being able to categorize new versus familiar objects would allow dolphins a rapid adaptation to novel environments. Visual laterality could be a prerequisite to this adaptability. To date, no study, to our knowledge, has analyzed the environmental factors that could influence their visual laterality. Results We investigated visual laterality expressed spontaneously at the water surface by a group of five common bottlenose dolphins (Tursiops truncatus) in response to various stimuli. The stimuli presented ranged from very familiar objects (known and manipulated previously) to familiar objects (known but never manipulated) to unfamiliar objects (unknown, never seen previously). At the group level, dolphins used their left eye to observe very familiar objects and their right eye to observe unfamiliar objects. However, eyes are used indifferently to observe familiar objects with intermediate valence. Conclusion Our results suggest different visual cerebral processes based either on the global shape of well-known objects or on local details of unknown objects. Moreover, the manipulation of an object appears necessary for these dolphins to construct a global representation of an object enabling its immediate categorization for subsequent use. Our experimental results pointed out some cognitive capacities of dolphins which might be crucial for their wild life given their fission-fusion social system and migratory behaviour.
Collapse
|