Effects of Stimulus Frequency and Intensity on the Middle Components of the Averaged Auditory Electroencephalic Response

Abstract

Middle components (la6tency 8–50 msec) of the averaged auditory electroencephalic response (AAER), evoked by brief duration tone bursts, were recorded from 11 normal-hearing subjects. Latency and amplitude measurements were made on five peaks (N a , P a , N b , P b , and N c ) of the AAER waveforms recorded for 27 experimental conditions: three conditions of stimulus frequency (250, 1000, and 4000 Hz) at each of nine conditions of signal intensity (a no-stimulus control and 10, 20, 30, 40, 50, 60, 70, and 80 dB re: group thresholds). Latency for each peak decreased with increased stimulus frequency, and it tended to decrease slightly with increases in stimulus intensity. Amplitude input-output characteristics varied with stimulus frequency and response peak. In general, the most linear input-output characteristics occurred for the early peaks and high stimulus frequencies. Characteristics for later peaks and lower frequencies tended to asymptote at moderate stimulus intensities. Between-subject variability was not much greater than within-subject variability for the single event auditory evoked potential (AEP). The variance of the AEP, however, was nearly as great (as much as two-thirds) as the variance of the background EEG, despite the large difference between AEP and background EEG amplitude.

Generation of human auditory steady-state responses (SSRs). II: Addition of responses to individual stimuli

“…The MLR components were labelled according to their polarity and in alphabetical order (Mendel and Goldstein, 1971;Thornton et al, 1977) even if the latency of the components may make them seem to belong to the slow potentials category (Picton et al, 1974;Picton and Smith, 1978). Wave V of the auditory brainstem response (ABR) and the P wave preceding Na (Picton et al, 1974;Picton and Smith, 1978;Kavanagh et al, 1984) were also identified.…”

Do estudo dos potenciais de média latência eliciados por logon em sujeitos do sexo feminino com audição normal

“…[15][16] Our data revealed no difference in latency time variability at the frequencies that were tested (Tab 2). Thornton et al 19 observed decreased latency with increased frequency. The 2000 Hz frequency elicited the highest number of responses except for Pb, which was mostly present at 500 Hz (Table 1).…”

“…Examples of this use include patients with multiple sclerosis, cerebral tumors, epilepsy, traumatic brain injury and learning disabilities. 8 A narrow band stimulus capable of stimulating specific cochlear regions could be used clinically 19 to quantitatively assess hearing loss. In other words, establishing electrophysiological thresholds at a specific frequency would truly be an electrophysiological pure tone audiometry.…”

“…This type of MLR would be ideal to assess subject with severe hearing loss at high frequencies,1 as it would be possible to estimate the electrophysiological auditory threshold using stimuli at various frequencies. Stimuli that elicit MLR and make assessments by specific frequencies possible are tone bursts, [3][4]19 tone pips 10,15,[17][18] and logon. 1 We employed logon in three frequency octaves, 500, 1000 and 2000 Hz.…”

“…Deflections mirror the auditory pathway segment located between the inferior colliculus and the medial geniculate body to the temporal lobe, namely the medial portion of Heschl's gyrus (subcortical or cortical regions). [11][12] Early auditory potentials and ABRs are neuronal potentials that require synchronous events to take place; the most frequently used stimulus is a click between 1 and 4 kHz.3 MLRs are post-synaptic potentials 9 that originate in dendrites and that may be elicited by clicks [13][14][15][16] or by tone pips, 10,15,17-1 8 tone bursts [3][4]19 or logon. 1 This opens the possibility of assessing specific frequencies using MLRs, as central auditory connections preserve the cochlear tonotopy.…”