Auditory cortex on the human posterior superior temporal gyrus

Abstract

The human superior temporal cortex plays a critical role in hearing, speech, and language, yet its functional organization is poorly understood. Evoked potentials (EPs) to auditory click‐train stimulation presented binaurally were recorded chronically from penetrating electrodes implanted in Heschl's gyrus (HG), from pial‐surface electrodes placed on the lateral superior temporal gyrus (STG), or from both simultaneously, in awake humans undergoing surgery for medically intractable epilepsy. The distribution of averaged EPs was restricted to a relatively small area on the lateral surface of the posterior STG. In several cases, there were multiple foci of high amplitude EPs lying along this acoustically active portion of STG. EPs recorded simultaneously from HG and STG differed in their sensitivities to general anesthesia and to changes in rate of stimulus presentation. Results indicate that the acoustically active region on the STG is a separate auditory area, functionally distinct from the HG auditory field(s). We refer to this acoustically sensitive area of the STG as the posterior lateral superior temporal area (PLST). Electrical stimulation of HG resulted in short‐latency EPs in an area that overlaps PLST, indicating that PLST receives a corticocortical input, either directly or indirectly, from HG. These physiological findings are in accord with anatomic evidence in humans and in nonhuman primates that the superior temporal cortex contains multiple interconnected auditory areas. J. Comp. Neurol. 416:79–92, 2000. © 2000 Wiley‐Liss, Inc.

The Sound of Concepts: Four Markers for a Link between Auditory and Conceptual Brain Systems

“…Strongest cortical currents (visualized in blue color) were observed in and close to left pSTG/MTG. cortex, both with respect to its functional an anatomical properties (Howard et al, 2000).…”

“…1 B). Based on the known neuroanatomy of the auditory system (Howard et al, 2000), the temporal plane comprises primary and secondary auditory cortex whereas the neighboring areas in superior and middle temporal gyri encompass auditory association areas. The MR signal was generally higher to real sounds than to acoustic noise in the temporal plane and in superior temporal cortex.…”

The effects of attentional load on auditory ERPs recorded from human cortex

“…The results of this study confirm previously reported intracranial findings that the presentation of brief tones produces a strong, multiphasic response in the human perisylvian area (Celesia, 1976;Richer et al, 1989;Liégeois-Chauvel et al, 1994;Halgren et al, 1995;Howard et al, 2000;Rosburg et al, 2004;Edwards et al, 2005). Lateral surface recordings from the temporal lobe in the present patients exhibited the largest negative peak in the averaged ERP waveform over the upper bank of the STG or the SF, with the maximal recording site more likely to occur over the SF as ISI decreases.…”

Functional imaging of the auditory processing applied to speech sounds

“…Evoked responses in PAC of Heschl's gyrus (HG) had response latencies ranging from 15 to 25 ms, which are compatible with the magnetoencephalography (MEG) data on click latency in PAC reported by Lü tkenhö ner et al (2003). Then, when this region of HG was electrically stimulated, it resulted in an evoked potential in PLST (Howard et al 2000;Brugge et al 2003). The average onset latency for this evoked response was only 2.0 ms, consistent with an ipsilateral corticocortical connection between HG and PLST.…”