Date of Award

1-1-2020

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School/Department

Department of Biomedical Sciences

Content Description

1 online resource (xxiii, 129 pages) : illustrations (some color)

Dissertation/Thesis Chair

Peter Brunner

Committee Members

Jonathan Carp, Valerie Bolivar, Richard Cole, Anthony Ritaccio

Keywords

brain signal attributes, Electrocorticography, Large-scale electrophysiological signals, Brain, Electrophysiology, Neural networks (Neurobiology), Electroencephalography, Anesthetics, Signal processing

Subject Categories

Biomedical Engineering and Bioengineering | Neuroscience and Neurobiology

Abstract

Brain’s electrophysiological signals are most certainly the ultimate source for studying the sophisticated neural network inside our cranium. The unparalleled complexity of these biosignalsis the quintessential manifestation of their underlying complicated neurophysiological processes. Studying brain signals on the cellular level provides valuable information regarding the brain’s electrophysiology on the small-scale. However, it is the remarkable network in the large-scale that gives rise to the brain’s extraordinary attributes and exceptional capabilities—perception, cognition, computation, and consciousness are all the emergent byproducts of the dynamic neuronal interactions on the network level. In this sense, the large-scale electrophysiological signals, recorded from the surface of cortex/scalp, are the sine qua non of brain research as they are instrumental in studying the concurrent activities of an ensemble of interconnected neurons. Surveying the extant neuroscience literature reveals the fact that the aforementioned signals have been the center of attention in two broad classes of research: 1) the basic neuroscientific research aimed at understanding the underlying principle that governs the human brain; 2) the translational clinical research with the primary objective of using brain signals to diagnose and treat neurological disorders. The paramount significance of each of the outlined classes incentivized me to design and navigate my doctoral research to address both branches to the best of ability—the pattern that is also reflected in the current manuscript. In this dissertation, we present a clinical research intended to study the feasibility of functional brain mapping under anesthesia. More specifically, we use ECoG signals to devise a mapping protocol that allows for the localization of the eloquent cortex in the anesthetized brain. The outcome of this translational research is of paramount importance for neurosurgical patients undergoing resective brain surgery. While the standard mapping techniques require patient cooperation, which is not always feasible, the method we propose can be implemented on unconscious patients and, therefore, can benefit a large population of patients who can not undergo the current mapping techniques. We also address the basic neuroscientific branch of research, as it was outlined above, by investigating brain signals’ fundamental characteristics and their implications. We demonstrate how disregarding the essential attributes of the neural time-series, in tandem with violating the underlying premise of the analysis techniques can be misleading and introduce dire confound in the neuroscientific inference.

Download

Share

COinS