Open AccessElectrophysiology of the Human Superior Temporal Sulcus during Speech Processing
Author(s) -
Kirill V. Nourski,
Mitchell Steinschneider,
Ariane E. Rhone,
Christopher K. Kovach,
Matthew I. Banks,
Bryan M. Krause,
Hiroto Kawasaki,
Matthew A. Howard
Publication year - 2020
Publication title -
cerebral cortex
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.694
H-Index - 250
eISSN - 1460-2199
pISSN - 1047-3211
DOI - 10.1093/cercor/bhaa281
Subject(s) - superior temporal sulcus , psychology , temporal lobe , neuroscience , categorization , superior temporal gyrus , auditory cortex , middle temporal gyrus , gyrus , temporal cortex , perception , cognitive psychology , audiology , cognition , epilepsy , functional magnetic resonance imaging , medicine , computer science , artificial intelligence
The superior temporal sulcus (STS) is a crucial hub for speech perception and can be studied with high spatiotemporal resolution using electrodes targeting mesial temporal structures in epilepsy patients. Goals of the current study were to clarify functional distinctions between the upper (STSU) and the lower (STSL) bank, hemispheric asymmetries, and activity during self-initiated speech. Electrophysiologic properties were characterized using semantic categorization and dialog-based tasks. Gamma-band activity and alpha-band suppression were used as complementary measures of STS activation. Gamma responses to auditory stimuli were weaker in STSL compared with STSU and had longer onset latencies. Activity in anterior STS was larger during speaking than listening; the opposite pattern was observed more posteriorly. Opposite hemispheric asymmetries were found for alpha suppression in STSU and STSL. Alpha suppression in the STS emerged earlier than in core auditory cortex, suggesting feedback signaling within the auditory cortical hierarchy. STSL was the only region where gamma responses to words presented in the semantic categorization tasks were larger in subjects with superior task performance. More pronounced alpha suppression was associated with better task performance in Heschl's gyrus, superior temporal gyrus, and STS. Functional differences between STSU and STSL warrant their separate assessment in future studies.