Sound identification in human auditory cortex: Differential contribution of local field potentials and high gamma power as revealed by direct intracranial recordings

Kirill V. Nourski, Mitchell Steinschneider, Ariane E. Rhone, Hiroyuki Oya, Hiroto Kawasaki, Matthew A. Howard, Bob McMurray

Research output: Contribution to journalArticle

14 Scopus citations


High gamma power has become the principal means of assessing auditory cortical activation in human intracranial studies, albeit at the expense of low frequency local field potentials (LFPs). It is unclear whether limiting analyses to high gamma impedes ability of clarifying auditory cortical organization. We compared the two measures obtained from posterolateral superior temporal gyrus (PLST) and evaluated their relative utility in sound categorization. Subjects were neurosurgical patients undergoing invasive monitoring for medically refractory epilepsy. Stimuli (consonant-vowel syllables varying in voicing and place of articulation and control tones) elicited robust evoked potentials and high gamma activity on PLST. LFPs had greater across-subject variability, yet yielded higher classification accuracy, relative to high gamma power. Classification was enhanced by including temporal detail of LFPs and combining LFP and high gamma. We conclude that future studies should consider utilizing both LFP and high gamma when investigating the functional organization of human auditory cortex.

Original languageEnglish (US)
Pages (from-to)37-50
Number of pages14
JournalBrain and Language
Publication statusPublished - Sep 1 2015



  • Averaged evoked potential
  • Classification analysis
  • Electrocorticography
  • Speech
  • Superior temporal gyrus

ASJC Scopus subject areas

  • Language and Linguistics
  • Experimental and Cognitive Psychology
  • Linguistics and Language
  • Cognitive Neuroscience
  • Speech and Hearing

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