SURPRISE-INDUCED DEAFNESS -- TEMPORAL CHARACTERISTICS OF A STIMULUS-DRIVEN LIMITATION IN AUDITORY SELECTIVE ATTENTION

Abstract

Organisms are inherently sensitive to unusual sound in the environment since hearing serves as an “early warning system”. Although this is an adaptive function for survival, the evaluation of such sound depletes the capacity limited cognitive resource and makes one susceptible to miss processing the task-relevant sound. This thesis focused on the temporal characteristics of such phenomenon and established a new paradigm named surprise-induced deafness (SiD). Series of experiments utilizing rapid auditory stream (RAP) revealed that presenting task-irrelevant, unexpected stimulus (surprise stimulus or SS) impaired conscious detection of designated target. Various factors such as proximity between the SS and target, heterogeneity and density of the SS were shown to affect the behavioral cost. Furthermore, SiD paradigm was directly compared to the paradigm which taps onto goal-directed limitation – i.e., auditory attentional blink or AAB. The result suggested that SiD indeed taps onto the stimulus-driven limitation in auditory selective attention.