Biophysical Modulations of Functional Connectivity

Resting-state low frequency oscillations have been detected in many functional magnetic resonance imaging (MRI) studies and appear to be synchronized between functionally related areas. Converging evidence from MRI and other imaging modalities suggest that this activity has an intrinsic neuronal origin. Multiple consistent networks have been found in large populations, and have been shown to be stable over time. Further, these patterns of functional connectivity have been shown to be altered in healthy controls under various physiological challenges. This review will present the biophysical characterization of functional connectivity, and examine the effects of physical state manipulations (such as anesthesia, fatigue, and aging) in healthy controls.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90432/1/brain-2E2011-2E0039.pd

The Multifaceted Interaction of Pain Perception in Collegiate Athletes

Deepening the present understanding of the multidimensional nature of athlete perceptions of pain requires attention to three specific gaps. First, the field currently lacks fundamental knowledge regarding the relationship between an individual’s athletic identity and the role of the brain in deciphering and responding to painful stimuli. Because athletes view injury as a potential loss of identity and thus a significant part of themselves (International Olympic Committee, n.d.), the severity they ascribe to pain is both conceptually and practically relevant. Second, the field has yet to fully explore the specific areas of the brain associated with subsequent functional connectivity as it relates to pain perception. Due to the increased activation of the brain’s neuromatrix during painful experiences (Peltz, Seifert, DeCol, Dorfler, Schwab, & et al., 2011), it is critical to highlight the specific areas and connections within the brain that are activated during painful events. Such activation patterns are referred to in the literature as functional connectivity. Third, the field has yet to document the potential impact of an individual’s past injury experiences on their perceptions of pain, thereby influencing future injury experiences. Because injury is commonplace in elite athletics (Sharma et al., 2011), it is important to examine how athletes subjectively perceive and react to the pain that accompanies an objective physical injury event

Toward a greater understanding of the brain processes underlying handgrip and handgrip fatigue

Handgrip is a ubiquitous human movement that determines how we interact with our environment. It is involved in almost every aspect of daily life (e.g. opening a door, handling cutlery, using tools) and like all human movement, its application is limited by muscle fatigue. However, the supraspinal mechanisms of handgrip and handgrip fatigue are not fully understood despite the importance of this fundamental movement, numerous publications, and its presence as a longstanding research topic. This thesis investigates the brain mechanisms of handgrip and handgrip fatigue using fMRI. It begins with a review of the literature in Chapter one, which evaluates the theories and evidence for central control of handgrip and muscle fatigue as well as describing the rationale to perform the experiments in this thesis. The methodology and analyses are also reviewed to provide rationale for their use and to facilitate the interpretation of subsequent experimental results. In order to understand the supraspinal mechanisms of handgrip and handgrip fatigue it is logical to first understand the most fundamental grip type (power vs. precision) and pattern (static vs. dynamic) by which handgrip can be performed