Auditory Evoked Potentials P50: Pure-tones vs Clicks. There is a Similar Supression?
PhD M.D, Seidel Guerra López
Faculty of Health Sciences, Universidad Politécnica y Artística del Paraguay (UPAP), Research Coordination of the Subsidiary in Ciudad Del, Av. Monseñor Rodríguez, KM 10, Ciudad del Este, Paraguay.
M.D, María de Los A. Pedroso Rodríguez
Faculty of Health Sciences, Universidad Politécnica y Artística del Paraguay (UPAP), Research Coordination of the Subsidiary in Ciudad Del, Av. Monseñor Rodríguez, KM 10, Ciudad del Este, Paraguay.
M.D, Diego Cantero
Faculty of Health Sciences, Universidad Politécnica y Artística del Paraguay (UPAP), Research Coordination of the Subsidiary in Ciudad Del, Av. Monseñor Rodríguez, KM 10, Ciudad del Este, Paraguay.
Gilvan Aguiar da Silva *
Faculty of Health Sciences, Universidad Politécnica y Artística del Paraguay (UPAP), Research Coordination of the Subsidiary in Ciudad Del, Av. Monseñor Rodríguez, KM 10, Ciudad del Este, Paraguay.
*Author to whom correspondence should be addressed.
Abstract
Objective: Clinical application of middle-latency auditory evoked potential (MLAEPs) has been increasing, highlighting the importance of understanding the nature of P50, a component of middle-latency auditory evoked potential. We manipulated stimulus frequency bands in auditory stimuli in order to investigate the nature of P50 in human auditory evoked potentials.
Methods: Two paradigms have been used to obtain P50: one is a conditioning /testing paradigm in which paired of pure tone (1000Hz) are delivered, and the other was presented paired of clicks, both with an intensity of 60 dB sound pressure level above the auditory threshold. A total of 30 healthy volunteers were recruited for this study among Center of genetic engineering (fifteen man and fifteen women, mean age of 36, 5). All without consumption of caffeine, cigarettes and drugs.
Results: No statistically significant differences occurred between the P50 amplitudes and latencies for the pure tone and those for the clicks.
Conclusions: Our present results indicate that P50 in humans may reflect a feed-forward mechanism of the brain where a preceding stimulus drives sensory gating mechanisms in preparation for a second stimulus, but the contained frequency doesn't influence on the P50. Both types (tones or clicks) can be used in the exploration of patient with this evoked potential.
Keywords: P50, evoked potential, MLAEPs, tones, clicks