Show simple item record



Item Description

dc.contributor.advisor Tamura, Eileen en_US
dc.contributor.author DeLong, Caroline M en_US
dc.date.accessioned 2009-03-06T19:21:04Z en_US
dc.date.available 2009-03-06T19:21:04Z en_US
dc.date.issued 2003-12 en_US
dc.identifier.uri http://hdl.handle.net/10125/6888 en_US
dc.description xi, 167 leaves en_US
dc.description.abstract Although the echolocation capabilities of bottlenose dolphins have been examined, little is known about how echolocating dolphins represent the information they use to recognize objects. When a dolphin echolocates a fish, it may represent only the sound of the fish's echoes. In contrast, the dolphin may represent the characteristics of the fish (e.g., size, shape) as well as the sound elements that convey its characteristics. The purpose of this project was to evaluate these representation theories by measuring a dolphin's ability to discriminate among objects, and then characterizing the acoustic information contained in the object echoes. A dolphin performed a match-to-sample task in which it was presented with a sample object and then had to choose the same object from a group of three objects. Acoustic measurements of the objects were made by ensonifying the objects with dolphin-like clicks and capturing the returning echoes. Acoustic features were extracted from the echoes: target strength, number of highlights, duration, peak frequency, center frequency, and bandwidth. To determine the role played by acoustic features in the dolphin's representations, an analysis of the dolphin's errors on the matching task was combined with information on the variation in acoustic features between objects. The dolphin's errors could not be fully explained by similarities in single acoustic features, linear combinations of these features, or correlations of echo spectra. These results suggest that dolphins use acoustic information in a complex way to determine object characteristics. To further investigate the nature of dolphins' representations, human participants were presented with slowed-down echoes from the same objects used in the dolphin matching task. The participants were asked to discriminate between the objects and report relevant discrimination cues. The participants' reports and an analysis of their errors indicated that the participants represented the sounds of the echoes. The error patterns of the humans did not always consistently match the error patterns of the dolphin, which suggests that the dolphin represented the objects differently than the humans. This project's results support the idea that dolphins directly represent object characteristics, not merely the sound elements that convey those characteristics. en_US
dc.publisher University of Hawaii at Manoa en_US
dc.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. en_US
dc.rights.uri https://scholarspace.manoa.hawaii.edu/handle/10125/2145 en_US
dc.title Object-centered representations in echolocating dolphins: evidence from acoustic analyses of object echoes and a human listening study en_US
dc.type Thesis en_US
dc.type.dcmi Text en_US
dc.contributor.department Psychology en_US
dc.description.degree PhD en_US
dc.date.graduated 2003-12 en_US
local.identifier.callnumber AC1 .H3 no. 4385 en_US

Item File(s)

Description Files Size Format View
Restricted for viewing only uhm_phd_4385_r.pdf 6.044Mb PDF View/Open
For UH users only uhm_phd_4385_uh.pdf 6.044Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record

Search


Advanced Search

Browse

My Account

Statistics

About