Steven M. Barlow
Date of this Version
Oh, H. (2016). Brain encoding of saltatory velocity-scaled somatosensory array in glabrous hand among neurotypical adults (Doctoral dissertation).
Neurons in human somatosensory cortex are somatotopically organized, with sensation from the lower limbs mediated by neurons near the midline of the brain, whereas sensations from the upper body, hands and orofacial surfaces are mediated by neurons located more laterally in a sequential map. Neurons in Brodmann's area (BA) 3b are exquisitely sensitive to tactile stimulation of these skin surfaces. Moreover, the location, velocity and direction of tactile stimuli on the skin's surface are discriminable features of somatosensory processing, however their role in fine motor control and passive detection are poorly understood in health, and as a neurotherapeutic agent in sensorimotor rehabilitation. To better understand the representation and processing of dynamic saltatory tactile arrays in the human somatosensory cortex, high resolution functional magnetic resonance (fMRI) is utilized to delineate neural networks involved in processing these complex somatosensory events to the glabrous surface of the hand.
The principal goal of this dissertation is to map the relation between a dynamic saltatory pneumatic stimulus array delivered at 3 different velocities on the glabrous hand and the evoked blood-oxygen level-dependent (BOLD) brain response, hypothesized to involve a network consisting of primary and secondary somatosensory cortices (S1 and S2), insular cortex, posterior parietal cortex (PPC), and cerebellar nuclei. A random-balanced block design with fMRI will be used to record the BOLD response in healthy right-handed adults. Development of precise stimulus velocities, rapid rise-fall transitions, salient amplitude, is expected to optimize the BOLD response.
Advisor: Steven M. Barlow