Traditional tactile sensory testing has relied heavily on delivery of single-site stimuli to the skin and querying test subjects on various qualities of those stimuli. While these methods are effective in making measures that characterize the peripheral nervous system, they lack in quantitatively assessing centrally mediated disorders of the nervous system. Additionally, the models from which the developments of such peripherally-based protocols originate are based more on historical precedence of prior techniques than on a characterization of the central nervous system. This thesis describes the development of not only novel methods for delivering multi-site tactile stimuli, but a novel approach for sensory testing based on models derived from measures of neural population response yielded from in-vivo and in-vitro animal experimentation. During the course of this study, two separate stimulators were designed and fabricated. The first, referred to as the "Two-Point Stimulator" (TPS), was a prototype developed to improve upon previously existing methods for delivering vibrotaction during psychophysical and physiological experimentation. To test the device, tracking protocols were used to assess the ability of human subjects to discriminate and localize between two near-adjacent skin sites under stimulus conditions of varying amplitude, frequency, location, and duration. Data collected were consistent with previously published reports, suggesting that one possible use of the device would be to provide a means for improved measures of spatio-tactile acuity. These studies were repeated on subjects with autism resulting in significant differences in performance from that of the normal population. Correlating data obtained from these psychophysical experiments with cortical measures, acquired primarily with optical imaging and neural recording techniques in animal experimentation, has allowed us to develop a better understanding of the cortical dynamics involved in somatosensory processing. A second stimulator fabricated during this period, the CM-1 (Cortical Metrics - Model #1), improves considerably upon the TPS, most notably in portability, cost, and functional capability. Current ongoing experimentation using this novel device allows an improved means for measuring tactile sensibility and assessing differences in cortical information-processing strategies between normal healthy control populations and populations with various neurological disorders, in both research and clinical settings
