Abstract
How organisms (including people) recognize distant objects is a fundamental question1. The correspondence between object characteristics (distal stimuli), like visual shape, and sensory characteristics (proximal stimuli), like retinal projection, is ambiguous. The view that sensory systems are ‘designed’ to ‘pick up’ ecologically useful information is vague about how such mechanisms might work2. In echolocating dolphins, which are studied as models for object recognition sonar systems, the correspondence between echo characteristics and object characteristics is less clear3. Many cognitive scientists assume that object characteristics are extracted from proximal stimuli, but evidence for this remains ambiguous. For example, a dolphin may store ‘sound templates’ in its brain and identify whole objects by listening for a particular sound. Alternatively, a dolphin's brain may contain algorithms, derived through natural endowments or experience or both, which allow it to identify object characteristics based on sounds. The standard method used to address this question in many species4,5,6,7 is indirect and has led to equivocal results with dolphins8,9,10. Here we outline an appropriate method and test it to show that dolphins extract object characteristics directly from echoes.
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References
Goldstein, E. B. (ed.) Blackwell Handbook of Perception (Blackwell, Oxford, 2001)
Gibson, J. J. The Ecological Approach to Visual Perception (Houghton Mifflin, Boston, 1979)
Au, W. W. L. The Sonar of Dolphins (Springer, New York, 1993)
Garbin, C. P. Visual-haptic perceptual nonequivalence of shape information and its impact upon cross-modal performance. J. Exp. Psychol. Hum. Percept. Perform. 14, 547–553 (1988)
Davenport, R. K. in Origins and Evolution of Language and Speech (eds Harnad, S. R., Steklis, H. D. & Lancaster, J.). Ann. NY Acad. Sci. 280, 143–149 (1976).
Gunderson, V. M., Rose, S. A. & Grant-Webster, K. S. Cross-modal transfer in high- and low-risk infant pigtailed macaque monkeys. Dev. Psychol. 26, 576–581 (1990)
Weiskrantz, L. & Cowey, A. Cross-modal matching in the rhesus monkey using a single pair of stimuli. Neuropsychology 13, 257–261 (1975)
Harley, H. E., Roitblat, H. L. & Nachtigall, P. E. Object representation in the bottlenose dolphin (Tursiops truncatus): Integration of visual and echoic information. J. Exp. Psychol. Anim. Behav. Process. 22, 164–174 (1996)
Pack, A. A. & Herman, L. M. Sensory integration in the bottlenosed dolphin: Immediate recognition of complex shapes across the senses of echolocation and vision. J. Acoust. Soc. Am. 98, 722–733 (1995)
Herman, L. M., Pack, A. A. & Hoffman-Kuhnt, M. Seeing through sound: Dolphins (Tursiops truncatus) perceive the spatial structure of objects through echolocation. J. Comp. Psychol. 112, 292–305 (1998)
Evans, W. E. Echolocation by marine delphinids and one species of fresh-water dolphin. J. Acoust. Soc. Am. 54, 191–199 (1973)
Au, W. W. L., Schusterman, R. J. & Kersting, D. A. in Animal Sonar Systems (eds Busnel, R. G. & Fish, J. F.) 859–862 (Plenum Press, New York, 1980)
Nachtigall, P. E., Murchison, A. E. & Au, W. W. L. in Animal Sonar Systems (eds Busnel, R. G. & Fish, J. F.) 945–947 (Plenum Press, New York, 1980)
Roitblat, H. L., Penner, R. H. & Nachtigall, P. E. Matching-to-sample by an echolocating dolphin. J. Exp. Psychol. Anim. Behav. Process. 16, 85–95 (1990)
Xitco, M. J. Jr & Roitblat, H. L. Object recognition through eavesdropping: Passive echolocation in bottlenose dolphins. Anim. Learn. Behav. 24, 355–365 (1996)
Au, W. W. L. & Pawloski, D. A. Cylinder wall thickness discrimination by an echolocating dolphin. J. Comp. Physiol. A 172, 41–47 (1992)
Acknowledgements
This work was supported by Walt Disney Company's Animal Programs, New College of Florida and the University of South Florida. All experimental procedures were evaluated and approved according to animal welfare regulations specified under National Institutes of Health guidelines. We thank: G. Bauer, J. Gory, A. Stamper, W. Fellner and J. Orth for discussion and manuscript review; D. Clark, D. Bickel, W. Fellner and K. Yannessa for research session and data management; J. Davis, A. Stamper, T. Hopkins, B. Stevens, J. Ogden and J. Mellen for administrative support; and M. Muraco, M. Barringer, B. Cavanaugh, L. Davis, D. Feuerbach, C. Goonen, L. Larsen-Plott, K. Odell and C. Litz for training the dolphin.
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41586_2003_BFnature01846_MOESM1_ESM.jpg
Supplementary Figure SI1: Figures SI1 – SI6. Fifty-four “junk” objects were presented in six groups that each contained three 3-object problems. In Groups 1, 3, and 5, the sample was presented echoically and the alternatives, visually. In Groups 2, 4, and 6, the sample was presented visually and the alternatives, echoically. Boxed objects were arbitrarily paired. (JPG 49 kb)
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Harley, H., Putman, E. & Roitblat, H. Bottlenose dolphins perceive object features through echolocation. Nature 424, 667–669 (2003). https://doi.org/10.1038/nature01846
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DOI: https://doi.org/10.1038/nature01846
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