scholarly journals Within Average Variability of the Acoustically Evoked Response

1971 ◽  
Vol 14 (1) ◽  
pp. 179-188 ◽  
Author(s):  
Lawrence W. Keating ◽  
Howard B. Ruhm
Keyword(s):  
Evoked Response ◽  
Evoked Responses ◽  
Eeg Activity ◽  
Quiet Condition ◽  
Male Subjects

This study explored the effects of various tasks, designed to alter the degree of “attention to stimuli” on the variability of the EEG activity which gives rise to the average acoustically evoked response. Evoked responses to 50 dB SL clicks were recorded from the vertex of eight male subjects under four conditions (1) quiet, (2) .counting, (3) discriminating, and (4) reading. Results showed the quiet condition to yield the greatest variability while reading exhibited the least.

scholarly journals Effect of Workload on the Auditory Evoked Brainstem Response

1984 ◽  
Vol 28 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Kirby Gilliland ◽  
Clark Shingledecker ◽  
Glenn Wilson ◽  
Karen Peio
Keyword(s):  
Auditory Brainstem ◽  
Evoked Response ◽  
Evoked Responses ◽  
Reasoning Task ◽  
Before And After ◽  
Post Test ◽  
Brainstem Response ◽  
Consistent Increase ◽  
Baseline Levels ◽  
Male Subjects

The purpose of this study was to explore the effect of workload level of a grammatical reasoning task on the auditory brainstem evoked response. Ten male subjects were administered three difficulty levels of a grammatical reasoning task. Brainstem evoked responses were recorded before and after the randomly presented workload conditions, as well as during each workload condition. The results revealed a consistent increase in Wave VI latency during all workload conditions, but no apparent differentiation between workload conditions. Post-test brainstem measures revealed that latency of Wave VI did not recover to pre-test baseline levels.

Evoked Potentials by Letters in Printed and Script Forms

1984 ◽  
Vol 59 (1) ◽  
pp. 227-232 ◽  
Author(s):  
Luciano Mecacci ◽  
Dario Salmaso
Keyword(s):  
Information Processing ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Adult Male ◽  
Visual Information ◽  
The Other ◽  
Behavioral Data ◽  
Evoked Responses ◽  
Amplitude Component ◽  
Male Subjects

Visual evoked potentials were recorded for 6 adult male subjects in response to single vowels and consonants in printed and script forms. Analysis showed the vowels in the printed form to have evoked responses with shorter latency (component P1 at about 133 msec.) and larger amplitude (component P1-N1) than the other letter-typeface combinations. No hemispheric asymmetries were found. The results partially agree with the behavioral data on the visual information-processing of letters.

5-HT activates nitric oxide-generating neurons to stimulate chloride secretion in guinea pig distal colon

1998 ◽  
Vol 275 (4) ◽  
pp. G829-G834 ◽  
Author(s):  
Atsukazu Kuwahara ◽  
Hirofumi Kuramoto ◽  
Makoto Kadowaki
Keyword(s):  
Nitric Oxide ◽  
Guinea Pig ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Chloride Secretion ◽  
Evoked Response ◽  
Evoked Responses ◽  
No Donor ◽  
Simultaneous Application

The participation of nitric oxide (NO) in serotonin (5-hydroxytryptamine; 5-HT)-evoked chloride secretion in guinea pig distal colon was examined. Submucosal/mucosal segments were mounted in Ussing flux chambers, and an increase in short-circuit current ( I sc) was used as an index of secretion. Addition of 5-HT to the serosal side produced a concentration-dependent (10−7–10−5M) increase in I sc caused by chloride secretion. N G-nitro-l-arginine (l-NNA) significantly reduced the 5-HT-evoked early (P-1) and late (P-2) responses to 61.1 and 70.6% of control, respectively. Neurally evoked response was also inhibited by l-NNA. The NO donor sodium nitroprusside (SNP, 10−4 M) increased basal I sc mainly because of chloride secretion. The SNP-evoked response was significantly reduced by tetrodotoxin but was unchanged by atropine or indomethacin. These results suggest that the 5-HT-evoked increase in I sc is associated with an NO-generating mechanism. Atropine significantly reduced the 5-HT (10−5 M)-evoked P-1 and P-2 responses to 71.8 and 19.7% of control, respectively. Simultaneous application of atropine andl-NNA further decreased the 5-HT-evoked responses more than either drug alone; application ofl-NNA and atropine decreased the 5-HT-evoked P-1 and P-2 responses to 68.5 and 39.2% of atropine-treated tissues, respectively. These results suggest that noncholinergic components of P-1 and P-2 responses are 71.8 and 19.7% of control, respectively, and that NO components of P-1 and P-2 responses are 32 and 61%, respectively, of the noncholinergic component of the 5-HT-evoked responses. The results provide evidence that NO may participate as a noncholinergic mediator of 5-HT-evoked chloride secretion in guinea pig distal colon.

Brainstem Evoked Response Audiometry

1983 ◽  
Vol 92 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Anne P. Giroux ◽  
Loring W. Pratt
Keyword(s):  
Evoked Response ◽  
Evoked Responses ◽  
Behavioral Testing ◽  
Eighth Nerve ◽  
Brainstem Evoked Response Audiometry ◽  
Threshold Levels ◽  
Evoked Response Audiometry

Brainstem evoked response audiometry is useful in the identification of threshold levels as well as in the diagnosis of eighth nerve tumors. The instrumentation is a modification of the electroencephalograph and an averaging computer; 3,000 clicks, 16/s, are presented and averaged for each printed response. Evoked responses can be obtained from a patient who is unable or unwilling to respond to conventional behavioral testing; best results are obtained from quiet or asleep patients.

The role of NMDA and non-NMDA excitatory amino acid receptors in the functional organization of primate retinal ganglion cells

1994 ◽  
Vol 11 (2) ◽  
pp. 317-332 ◽  
Author(s):  
Ethan D. Cohen ◽  
Robert F. Miller
Keyword(s):  
Amino Acid ◽  
Ganglion Cell ◽  
Functional Organization ◽  
Ganglion Cells ◽  
Excitatory Amino Acid ◽  
Evoked Response ◽  
Evoked Responses ◽  
Retinal Ganglion ◽  
Firing Rates

AbstractThe role of excitatory amino acid (EAA) receptors in primate retinal ganglion cell function was analyzed in a superfused retina-eyecup preparation using single-unit, extracellular recording techniques. The effects of bath applied L-2–amino-4–phosphonobutyrate (APB), N-methyl-D-aspartate (NMDA), and non-NMDA EAA receptor agonists and antagonists were examined on the light-evoked responses and resting firing rates of ganglion cells. APB (30–100 μM) reduced or blocked the light-evoked responses and resting firing rates of all ON-center ganglion cells; higher doses of APB (100 μM) were required to block the light-evoked responses of ON-transient cells. In contrast, an increase in resting firing rates was observed when L-APB was applied to some OFF-center ganglion cells. The EAA agonists kainate (KA) (10–20 μM) and NMDA (200–350 μM) increased the firing rate of virtually all ganglion cells examined. Quisqualate (10–20 μM) increased firing in most cells, but occasionally (4/13 cases) produced inhibition. The NMDA antagonist D-amino-phosphono-heptanoic acid (D-AP7) (200–250 μM) reduced the light-evoked responses of ganglion cells by an average of 12% from control levels, while resting firing rates declined 37%. In the presence of D-AP7, the basic receptive-field characteristics of cells were not significantly altered. In contrast, two non-NMDA receptor antagonists, NBQX (2,3–Dihydroxy-6–nitro-7–sulfamoyl-benzo-(F)-quinoxalinedione) and DNQX (6,7–dinitro-quinoxaline-2,3–dione), produced substantial reductions in the light-evoked responses (82%) and resting firing rates (87%) of all ganglion cell classes. A striking observation in some neurons was the recovery of a persistent transient light-evoked response in the presence of NBQX. This NBQX-insensitive, light-evoked response was always blocked by adding D-AP7. Thus, neurotransmission from bipolar to ganglion cells in primates is mediated predominantly by non-NMDA EAA receptors, with NMDA receptors forming a minor component of the light-evoked response.

Short-Term Habituation of the Infant Auditory Evoked Response

1973 ◽  
Vol 16 (4) ◽  
pp. 637-641 ◽  
Author(s):  
Michael F. Dorman ◽  
Robert Hoffmann
Keyword(s):  
Evoked Response ◽  
Synthetic Speech ◽  
Evoked Responses ◽  
Stimulus Amplitude ◽  
Average Amplitude ◽  
Short Term ◽  
Speech Stimuli ◽  
Auditory Evoked Response ◽  
Stimulus Train

Short-term habituation of the vertex auditory evoked response was studied in six infants (age 10 to 14 weeks). The infants were presented trains of four synthetic speech stimuli. The average amplitude of the evoked responses was largest to the first member of the stimulus train and then decreased rapidly. The average amplitudes to the second, third, and fourth stimuli in the train were 36, 41, and 22% of the first stimulus amplitude, respectively. The results suggest that the auditory evoked response of awake infants satisfies several of the criteria for short-term habituation.

Summed Evoked Responses Using Pure-Tone Stimuli

1966 ◽  
Vol 9 (2) ◽  
pp. 266-272 ◽  
Author(s):  
Geary A. McCandless ◽  
Lavar Best
Keyword(s):  
Pure Tone ◽  
Stimulus Frequency ◽  
Evoked Response ◽  
Evoked Responses ◽  
Response Patterns ◽  
Additional Advantage ◽  
Auditory Evoked Responses ◽  
Auditory Responses ◽  
Pure Tones ◽  
Major Consideration

Selected pure tones were used as stimuli in a study of evoked auditory responses in 25 adults. The effects of stimulus frequency, intensity, and duration on the evoked response were evaluated. Pure-tone stimuli appear to be as satisfactory as click stimuli in eliciting auditory evoked responses and have the additional advantage of providing more information relative to auditory function. Evoked response patterns were essentially the same for 500 Hz (cps), 2,000 Hz, and 4,000 Hz. Latencies were longer for the components of pure-tone-evoked responses than for click-evoked responses. Evoked responses may be influenced by (1) changes in stimulus parameters and (2) changes in subject’s psychophysical state. These variables become a major consideration in the recognition of the evoked response at intensity levels near threshold.

A surface recorded vestibular evoked response to acceleration in cats

1984 ◽  
Vol 98 (S9) ◽  
pp. 111-119 ◽  
Author(s):  
J. Elidan ◽  
H. Sohmer ◽  
M. Nitzan
Keyword(s):  
Brain Function ◽  
Vestibular Nucleus ◽  
Auditory Brainstem ◽  
Evoked Response ◽  
Evoked Responses ◽  
Response Patterns ◽  
Viiith Nerve ◽  
The Brain ◽  
Vestibular Pathways ◽  
Averaging Techniques

AbstractVestibular evoked responses to repetitive acceleration stimuli were recorded by skin electrodes in cats using filtering and averaging techniques. The response is made up of six—eight waves during the first 10 msec following the stimulus. Longer latency myogenic responses had large amplitude and disappeared following the paralysis of the animals. The neurogenic waves disappeared after the destruction of both inner ears or the excision of both eighth nerves and following death. Destruction of the inner ear, or excision of the VIIIth nerve on one side leads to response patterns of excitation vs. inhibition when appropriate excitatory and inhibitory acceleration stimuli are applied. The possible generators of the evoked responses are discussed in the light of the physiology of the vestibular pathways, and the results of the present experiments suggest that the generators of the first and second waves are the vestibular nerve and vestibular nucleus respectively. In addition, the vestibular evoked response seemed to be more sensitive to ischemia of the brain than the auditory brainstem evoked response and may therefore reflect better changes in brain function.

Topographic deficits in alpha-range resting EEG activity and steady state visual evoked responses in schizophrenia

2015 ◽  
Vol 168 (1-2) ◽  
pp. 145-152 ◽  
Author(s):  
Michael R. Goldstein ◽  
Michael J. Peterson ◽  
Joseph L. Sanguinetti ◽  
Giulio Tononi ◽  
Fabio Ferrarelli
Keyword(s):  
Steady State ◽  
Evoked Responses ◽  
Eeg Activity ◽  
Visual Evoked Responses ◽  
Visual Evoked

Masking Level Differences: Auditory Evoked Responses with Homophasic and Antiphasic Signal and Noise

1979 ◽  
Vol 22 (2) ◽  
pp. 403-411 ◽  
Author(s):  
A. Yonovitz ◽  
C. L. Thompson ◽  
Joseph Lozar
Keyword(s):  
Pure Tone ◽  
Evoked Response ◽  
Evoked Responses ◽  
Auditory Evoked Responses ◽  
Auditory Evoked Response ◽  
Level Difference ◽  
Masking Level Difference ◽  
Objective Quantification

Two studies were devised to determine if objective quantification of the masking level difference is possible using the auditory evoked response (AER). In the first study, click stimuli were presented under three conditions: both the stimulus and masker in phase (SoNo); stimulus in phase, masker antiphasic (SoN π ); and stimulus antiphasic with masker in phase (S π No). In the second study 1000 Hz pure-tone stimuli were presented under SoNo and S π No phasic conditions. AER’s were obtained at various intensity levels for each condition. The AER demonstrated differences in N 1 -P 2 amplitudes evoked by the homophasic and antiphasic conditions for threshold and suprathreshold levels.

Sign in / Sign up

Export Citation Format

Share Document