2002 Fiscal Year Final Research Report Summary
Auditory and vocal functions of the chimpanzee
| Project/Area Number |
13410025
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
実験系心理学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KOJOMA Shozo Primate Research Institute Professor, 霊長類研究所, 教授 (70027499)
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| Project Period (FY) |
2001 – 2002
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| Keywords | chimpanzee / Auditory cognition / Vocalization / Individual recognition / Early vocal development / Mother-infant vocal interaction |
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| Research Abstract |
In this research project, I found a chimpanzee (a female chimpanzee, Pan) can identify other individuals in her group only by their vocal sounds. Researchers found individuality in pant hoots, but not in pant grunts and screams. The present study showed that she can match not only pant hoots, but also pant grunts and screams with a photograph of group members in an auditory-visual intermodal matching to sample task. She can also identify each caller in duets of pant hoots. The importance of the fundamental frequency and frequency components below and above 1 kHz for individual recognition by vocal sounds was examined. It is found that the fundamental frequency is important for identification. Thus, researchers have underestimated the ability of the chimpanzee to identify vocalizers by vocal sounds. She matched different vocal sounds with with different facial actions in the same chimpanzee.
Early vocal development of a chimpanzee infant was studied and compared with that of a human-raised chimpanzee infant. Both infants showed a similar developmental pattern: they enhanced elicitability of vocal sounds at about 55 days of age. Vocal interactions of the three chimpanzee mother-infant pairs were examined. Vocal interactions were observed only in a pair (Pan-Pal). Other pairs did not show interactions. Pan received vocal operant training in early infancy. The mother responded to infant crying vocalization by pant grunt-like sounds.
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Research Products
(6 results)
