Visual laterality in dolphins: importance of the familiarity of stimuli

BMC Neuroscience

Research Article

Martin Böye¹  Catherine Blois-Heulin²  Mélodie Crével²  Alban Lemasson² 

[1] Département scientifique, Planète Sauvage, 44710, Port-Saint-Père, France;UMR 6552 University of Rennes 1 - CNRS, 35380, Station Biologique, Paimpont, France;

关键词: Left Hemisphere;    Familiar Object;    Bottlenose Dolphin;    Binocular Vision;    Monocular Vision;   

DOI  :  10.1186/1471-2202-13-9

 received in 2011-07-12, accepted in 2012-01-12,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundMany 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.ResultsWe 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.ConclusionOur 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.

【 授权许可】

CC BY   
© Blois-Heulin et al; licensee BioMed Central Ltd. 2012