Award Date

8-1-2012

Degree Type

Thesis

Degree Name

Master of Arts (MA)

Department

Psychology

First Committee Member

Joel S. Snyder

Second Committee Member

Erin E. Hannon

Third Committee Member

Jefferson Kinney

Fourth Committee Member

Pierre Lienard

Number of Pages

52

Abstract

During repeating sequences of low (A) and high (B) tones in an "...ABAB..." pattern, the likelihood of hearing two separate streams ("streaming") increases with more repetitions of the patterns, a phenomenon referred to as "buildup". Previous studies have shown that buildup is frequency specific (Anstis & Saida, 1985) and that its biasing effects decays over several seconds (Beauvois & Meddis, 1997). No study has examined whether the frequency specificity of buildup persists for such a long duration. To address these issues, Experiment 1 tested the decay of frequency-specific and non-frequency specific buildup. The results revealed that (1) frequency-specific buildup effects were strongest during short decay intervals and decayed with longer intervals, (2) non-frequency-specific buildup showed weaker buildup effects and less decay, and (3) both types of buildup had significant effects compared to a silence baseline comparison even after long decay intervals. It is assumed non-frequency-specific buildup involved mechanisms in a high-level auditory area not finely tuned to frequency and sensitive to complex features. Therefore, Experiment 2 tested whether mechanisms subserving buildup occur in areas of the auditory pathway sensitive to rhythmic pattern. The main results revealed that (1) frequency-specific and non-frequency specific buildup effects were both disrupted by rhythmic pattern irregularity given their effects were large without such irregularity, and (2) replicated all other aspects of Experiment 1. The results of both experiments confirmed the presence of a frequency-specific mechanism subserving buildup that may be longer-lasting than previously recognized and further supported the presence of non-frequency specific mechanisms that are also long-lasting. Additionally, buildup appeared to involve mechanisms in high-level auditory areas sensitive to rhythmic pattern. Taken together, this study demonstrated buildup is a complex process that involves multiple levels of analysis along the auditory pathway.

Keywords

Auditory perception; Auditory scene analysis; Auditory stream segregation; Audio frequency; Pattern perception

Disciplines

Cognition and Perception | Cognitive Psychology | Neurosciences | Psychology

Language

English


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