Authors:
Erik Edwards
Maryam Soltani
Won Kim
Sarang S. Dalal
Srikantan S. Nagarajan
Mitchel S. Berger
Robert T. Knight
Date: 2009
DOI: 10.1152/jn.90954.2008
PubMed: 19439673
Abstract:
Comparison of time–frequency responses and the event-related potential to auditory speech stimuli in human cortex. J Neurophysiol 102: 377–386, 2009. First published May 13, 2009; doi:10.1152/jn.90954.2008. We recorded the electrocorticogram directly from the exposed cortical surface of awake neurosurgical patients during the presentation of auditory syllable stimuli. All patients were unanesthetized as part of a language-mapping procedure for subsequent left-hemisphere tumor resection. Time–frequency analyses showed significant high-gamma (high : 70 –160 Hz) responses from the left superior temporal gyrus, but no reliable response from the left inferior frontal gyrus. Alpha suppression (: 7–14 Hz) and event-related potential responses exhibited a more widespread topography. Across electrodes, the suppression from 200 to 450 ms correlated with the preceding (50 –200 ms) high increase. The results are discussed in terms of the different physiological origins of these electrocortical signals.