Files
Abstract
Context is a critical component to all empirical research and must always be carefully considered. In early auditory and visual sensory processing, it can be employed to differentiate top-down mediated biasing signals from lower-level fundamental sensory function. Early sensory processes have been shown to deviate from normal function across dimensions of the normal aging process, pathological cases, and basic cognitive control capacity. The auditory and visual streams are complex, reciprocal in nature, and highly transient in nature. Determining where in the streams top-down control is implemented requires exceptional temporal precision and must be evaluated using the imaging modalities capable of achieving millisecond precision. In this dissertation, contextual modulation will be used as a tool to impose top-down biasing in a manner that will allow for identifying group variance across multiple group characteristics under carefully crafted semi-static auditory and visual stimuli that make clear how top-down processes mediate basic sensory cortical processing.