| This Ph.D. Thesis is concerned with the neural correlates of word-level language processing in skilled English readers. It begins with a short historical prelude into the history of the functional neuroimaging of cognition, which is gradually narrowed to the more specialized case of language processes. The first section of Chapter One provides a broad overview of the physical basis of signals measured through the imaging modalities most common in this domain of study. What is known of the relationship between the physical signals and the physiology of interest is discussed in the latter part of this same Chapter, along with outstanding questions and current issues in multi-modality imaging. Chapter Two functions as an in-depth review of the current literature; it begins by illuminating the broadly inconsistent findings of prior studies that investigated the brain basis of lexical processing, and discusses possible explanations for this variability. The second section of Chapter Two uses the plethora of studies reporting the most basic contrast (i.e., pronounceable word-like stimuli versus a basic baseline) to outline the core network of neural regions involved in word-level language processing. In Chapter Three, a brief review of the terminology and common approaches to MEG source localization is presented, as well as a discussion of the scientific issues related to each approach and source localization techniques in general. Chapter Four introduces the experiments that comprise the Thesis research, and describes the methods and materials used to acquire and analyze the neural data. The results of each experiment are presented sequentially in Chapter Five, and Chapter Six provides discussion of these results in the same sequential format. Chapter Six closes with a General Discussion that includes data from all three experiments, and Chapter Seven provides a conclusion to the Thesis. |
