Abstract
Weise, A., Schröger, E., & Bendixen, A. (2012). The processing of concurrent sounds based on inharmonicity and asynchronous onsets: An object-related negativity (ORN) study. Brain Research, 1439, 73-81.
The processing of concurrent sounds based on inharmonicity and asynchronous onsets: An object-related negativity (ORN) study
This study addresses the processing of concurrent sounds based on inharmonicity and onset asynchrony cues. We used harmonic complex sounds with one component starting marginally (40 ms) or considerably (500 ms) earlier than the complex and being slightly (3%) or strongly (13%) inharmonic. To index sound segregation of concurrent events, we measured the object-related negativity (ORN) component of the event-related potential. We contrasted two hypotheses: According to the concurrent-segregation hypothesis, increased onset asynchrony is assumed to promote segregation of the leading partial from the harmonic complex, which should be reflected in increased ORN amplitudes. That is, even with large onset asynchronies concurrent events would be processed by a simultaneous sound segregation mechanism. According to the sequential-integration hypothesis, however, with increased onset asynchrony concurrent cues are assumed to be less considered by simultaneous grouping processes, which should be reflected in attenuated ORN amplitudes for long onset asynchronies. This assumption is based on the notion that due to sequential integration, a stable percept of the leading partial has been developed within ~ 350 ms after sound onset, thus less processing is required from scene analysis mechanisms based on concurrent cues. Indeed, with increased onset asynchrony ORN was found to decrease, which supports the sequential-integration hypothesis. In line with previous data, ORN was also found to increase with increased inharmonicity. The absence of an inharmonicity × onset asynchrony interaction further supports the assumption that both cues are used in different ways for simultaneous sound segregation.
Contact
Cognitive and Biological Psychology
University of Leipzig
Faculty of Life Sciences
Institute of Psychology
Neumarkt 9-19
D-04109 Leipzig
Secretariat
Dagmar Schrödl
Phone: +49 341 97-39570
Email: dagmar dot schroedl at uni-leipzig dot de
Fax: +49 341 97-39271