Anatomy and Neuroscience - Research Publications
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ItemValproic acid is associated with cognitive decline in HIV-infected individuals: a clinical observational study(BMC, 2006-12-06)BACKGROUND: Valproic acid (VPA) is often used to control pain in HIV-related neuropathy. However, the effect of VPA on cognitive functions in advanced HIV-infected individuals is largely unknown. A recent study would suggest that it may have a neuroprotective effect, the doses used were low and the observation period short. METHODS: We used a well studied HIV-infected cohort assessed for a median of 15 (range 6-27 months) to determine whether individuals who were receiving VPA showed any cognitive benefits. Multiple regression procedures allowed us to control for the effects of HAART and HIV disease status as well as numbers of visits and variation in VPA intake over-time. RESULTS: We found a negative effect of VPA (mean dose of 850 mg/d for 18 months on average; range 6-27 months) on cognitive performance in eight advanced HIV-infected individuals compared to 32 advanced HIV-infected individuals on no VPA who had comparable neuropsychological performance at baseline. Control for plasma HIV viral load provided similar results. CONCLUSION: Our results suggest that further studies of VPA in advanced HIV-infection should cautiously include high doses over prolonged periods of at least 18 months in order to more accurately determine whether the posited neuroprotective benefit of VPA still occurs or whether it is replaced by toxicity.
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ItemNo Preview AvailableComparison of voice acquisition methodologies in speech research(SPRINGER, 2008-11)The use of voice acoustic techniques has the potential to extend beyond work devoted purely to speech or vocal pathology. For this to occur, however, researchers and clinicians will require acquisition technologies that provide fast, accurate, and cost-effective methods for recording data. Therefore, the present study aimed to compare industry-standard techniques for acquiring high-quality acoustic signals (e.g., hard drive and solid-state recorder) with widely available and easy-to-use, computer-based (standard laptop) data-acquisition methods. Speech samples were simultaneously acquired from 15 healthy controls using all three methods and were analyzed using identical analysis techniques. Data from all three acquisition methods were directly compared using a variety of acoustic correlates. The results suggested that selected acoustic measures (e.g., f 0, noise-to-harmonic ratio, number of pauses) were accurately obtained using all three methods; however, minimum recording standards were required for widely used measures of perturbation.
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ItemNo Preview AvailableStandardization of pitch-range settings in voice acoustic analysis(PSYCHONOMIC SOC INC, 2009-05)Voice acoustic analysis is typically a labor-intensive, time-consuming process that requires the application of idiosyncratic parameters tailored to individual aspects of the speech signal. Such processes limit the efficiency and utility of voice analysis in clinical practice as well as in applied research and development. In the present study, we analyzed 1,120 voice files, using standard techniques (case-by-case hand analysis), taking roughly 10 work weeks of personnel time to complete. The results were compared with the analytic output of several automated analysis scripts that made use of preset pitch-range parameters. After pitch windows were selected to appropriately account for sex differences, the automated analysis scripts reduced processing time of the 1,120 speech samples to less than 2.5 h and produced results comparable to those obtained with hand analysis. However, caution should be exercised when applying the suggested preset values to pathological voice populations.