Recording of Auditory Evoked Potentials in Man Using Chronic Subdural Electrodes

Abstract

With the aid of chronic subdural electrodes we have been able to record from the posterior banks of the sylvian fissure, auditory evoked potentials (AEPs) that had morphologies and peak latencies compatible with the primary AEPs described by Celesia and Puletti (1969). These AEPs had amplitudes that were not only affected by the side of stimulus presentation but were maximal in an area close to the primary auditory cortex. The AEPs also displayed an extremely steep spatial gradient and were not altered by pentobarbitone sodium and nitrous oxide anaesthesia. Together, these properties suggest that these subdurally recorded potentials are near-field evoked potentials from the primary auditory cortex. The focal nature of these potentials also allows them to be used as effective electrophysiological tools for localization of the primary auditory cortex in patients.

The Effect of Acupuncture Stimulation on the Middle Latency Auditory Evoked Potential.

“…The auditory cortex of the superior temporal gyrus was suggested as the generator source of Pa, based on many clinical reports of missing or abnormal Pa components in subjects with temporal lobe lesions (Graham et al 1980;Kraus et al 1982;Ozdamar et al 1982;Rosati et al 1982;Ozdamar and Kraus 1983), and on topographical mapping (Lee et al 1984) and parametric studies (Erwin and Buchwald 1986a, b). The neuromagnetic study by Pelizzone et al (1987) suggests that the supratemporal auditory cortex is active during Pa and that a change in wave form morphology occurs on the anterior-posterior plane.…”

Contemporary model of language organization: an overview for neurosurgeons

“…As a testament to his ingenuity, the technique of speech mapping has been largely unchanged over time except for minor modifications in this above described technique, and can also be performed extraoperatively with implanted electrode arrays. 59,60 Penfield described several forms of speech interference from electrical stimulation, including total speech arrest (anarthria), hesitation, slurring, distortion, repetition, and confusion (jumping from "six" to "twenty" and then back to "nine"). 86 During the picture-naming task, he described other more complex effects such as the inability to name with retained ability to speak and the perseveration of words that were presented previously.…”

A comparison of auditory evoked potentials to acoustic beats and to binaural beats

“…These source differences were widely discussed in our earlier report (Pratt et al, 2009) and were reconciled by differences in methods of recording (electric or magnetic fields), beat frequency (40 Hz or a few Hz), source models (dipole, current density distribution or no model with only scalp distribution). These methodological variations resulted in differences in the relative contributions of symmetrical, high-frequency thalamocortical and lateralized, slower cortical sources to the scalp-recorded responses in addition to the relative contribution of slower cortical activity from secondary non-specific cortex and middle latency activity from specific auditory cortex (Galambos et al, 1981;Kileny and Shea, 1986;Hashimoto, 1982;Lee et al, 1984;McGee et al, 1992;Zaaroor et al, 2003). The earlier studies and this study thus complement each other, showing that beats, most probably present as early as the brainstem (human steady-state potentials and animal studies), persist through auditory processing at the thalamus and specific auditory cortex (previous beats studies) and further involve cortical non-specific areas in the left temporal lobe (this study).…”