Biomedical subjects

M I Mendel

Publications and source records attributed to M I Mendel.

At least 19 recordsLinked to original sources

PubMed1992

Place specific influences on the wave I to V interpeak latency of the auditory brain-stem response.

There is controversy over whether the wave I to V interpeak latency (I-V IPL) of the auditory brain-stem response can be manipulated by cochlear processing. In this study, a forward masking paradigm was used to test the predictions of two contrasting models of I-V IPL generation. The paradigm was designed to determine if the I-V IPL can be affected by masking selected portions of the cochlear response region. The results from ten normal hearing subjects suggest that: (1) waves I and V can be masked semi-independent of each other, and (2) the I-V IPL can be shortened or prolonged by masking the basal or apical portion of the cochlear response region respectively. These findings support the hypothesis that, at least in normal hearing subjects, wave V is biased to reflect more apical cochlear events than wave I. Additionally, they offer tentative support for anecdotal reports of shortened I-V IPLs in the presence of high-frequency hearing loss.

Adult↗

PubMed1992

Quantification technique for the middle latency response.

Few objective analysis techniques have been developed for, or applied to, the auditory evoked middle latency response (MLR). This report demonstrates the applicability of the Fsp statistical technique (Elberling and Don, 1984) to the MLR time domain. Subjects for this study were 10 normal hearing young adults. The stimuli were 60, 40, 20 dB nHL clicks and a NS control. Evoked responses were obtained as a series of 10,000 individual traces for each stimulus presentation and analyzed off line to determine the applicability of the Fsp technique. In addition, the effects of filtering and time window size were examined to determine the optimum collection characteristics for the Fsp analysis method. The results indicate that the Fsp technique is a viable tool for estimating signal-to-noise characteristics of the MLR. When using the Fsp technique with the MLR the high-pass filter should be set to 20 Hz so that a 50-msec time window can be used.

Acoustic Stimulation↗

PubMed1977

Influence of succinylcholine on middle component auditory evoked potentials.

Auditory evoked potentials in the middle component time domain (post-stimulus, 8 to 50 msec) were recorded in response to 1,000-Hz tone pips in a normal-hearing adult subject. Electromyographic (EMG) responses in response to ulnar nerve shocks were recorded from the ipsilateral hypothenar muscles. With the assistance of an anesthesiologist, data were collected during a normal resting state, a state of light sedation, and a state of complete skeletal muscle paralysis from succinylcholine administration. During the paralyzed state, there was abolition of the normal EMG responses seen in the resting and sedated states. The auditory evoked potentials, however, appeared unchanged during the paralyzed state, indicating that they were not of myogenic origin.

Acoustic Stimulation↗

PubMed1977

Effects of stimulus frequency and intensity on the middle componenets of the averaged auditory eletroencephalic response.

Middle components (latency 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 (Na, Pa, Nb, Pb, and Nc) 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 fe: 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.

Acoustic Stimulation↗

PubMed1975

Audiometric comparison of the middle and late components of the adult auditory evoked potentials awake and asleep.

The middle and the late components of auditory evoked potentials were alternately recorded in sequential sets from 28 adults, both awake and asleep. Sleep was induced by secobarbital and was monitored for depth. 1000 c/sec tone pips in one laboratory or filtered clicks in the other were delivered at 10, 20 or 30 dB sensation level. Control collections without stimulation were included. For the middle responses a single simple scoring template and one set of voltage criteria could be used for all stages of waking and sleeping. For late responses different templates and voltage criteria were needed. Estimates of the threshold of detection of the evoked potentials were based on the percentage of clearly positive responses was often not attained at 30 dB SL, i.e., the threshold was indeterminate. In light sleep and awake the middle responses of most subjects gave thresholds more sensitive than the late by 10-15 dB and also fewer indeterminate trials. The results in our two laboratories agreed closely in spite of differences in equipment and details of procedure. The relatively low thresholds of the middle responses (median 17.5 dB SL awake and 15 dB SL in light sleep) suggest that the middle responses must be considered seriously for use in clinical electric response audiometry, even though one of the 28 subjects failed to yield any identifiable middle responses.

Adult↗

PubMed1975