Human Steady-State Visual and Auditory Evoked Potential Components During a Selective Discrimination Task

1995 ◽  
Vol 1 (3) ◽  
pp. 1-9 ◽  
Author(s):  
Thomas F. Collura
Keyword(s):  
Steady State ◽  
Discrimination Task ◽  
Evoked Potential ◽  
Auditory Evoked Potential

Forty-hertz Midlatency Auditory Evoked Potential Activity Predicts Wakeful Response during Desflurane and Propofol Anesthesia in Volunteers 

1999 ◽  
Vol 91 (5) ◽  
pp. 1209-1209 ◽  
Author(s):  
Robert C. Dutton ◽  
Warren D. Smith ◽  
Ira J. Rampil ◽  
Ben S. Chortkoff ◽  
Edmond I Eger
Keyword(s):  
Steady State ◽  
Frequency Spectrum ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Correct Prediction ◽  
Time Frequency ◽  
Prediction Probability ◽  
End Tidal ◽  
40 Hz

Background Suppression of response to command commonly indicates unconsciousness and generally occurs at anesthetic concentrations that suppress or eliminate memory formation. The authors sought midlatency auditory evoked potential indices that successfully differentiated wakeful responsiveness and unconsciousness. Methods The authors correlated midlatency auditory evoked potential indices with anesthetic concentrations permitting and suppressing response in 22 volunteers anesthetized twice (5 days apart), with desflurane or propofol. They applied stepwise increases of 0.5 vol% end-tidal desflurane or 0.5 microg/ml target plasma concentration of propofol to achieve sedation levels just bracketing wakeful response. Midlatency auditory evoked potentials were recorded, and wakeful response was tested by asking volunteers to squeeze the investigator's hand. The authors measured latencies and amplitudes from raw waveforms and calculated indices from the frequency spectrum and the joint time-frequency spectrogram. They used prediction probability (PK) to rate midlatency auditory evoked potential indices and concentrations of end-tidal desflurane and arterial propofol for prediction of responsiveness. A PK value of 1.00 means perfect prediction and a PK of 0.50 means a correct prediction 50% of the time (e.g., by chance). Results The approximately 40-Hz power of the frequency spectrum predicted wakefulness better than all latency or amplitude indices, although not all differences were statistically significant. The PK values for approximately 40-Hz power were 0.96 during both desflurane and propofol anesthesia, whereas the PK values for the best-performing latency and amplitude index, latency of the Nb wave, were 0.86 and 0.88 during desflurane and propofol (P = 0.10 for -40-Hz power compared with Nb latency), and for the next highest, latency of the Pb wave, were 0.82 and 0.84 (P < 0.05). The performance of the best combination of amplitude and latency variables was nearly equal to that of approximately 40-Hz power. The approximately 40-Hz power did not provide a significantly better prediction than anesthetic concentration; the PK values for concentrations of desflurane and propofol were 0.91 and 0.94. Changes of 40-Hz power values of 20% (during desflurane) and 16% (during propofol) were associated with a change in probability of nonresponsiveness from 50% to 95%. Conclusions The approximately 40-Hz power index and the best combination of amplitude and latency variables perform as well as predictors of response to command during desflurane and propofol anesthesia as the steady-state concentrations of these anesthetic agents. Because clinical conditions may limit measurement of steady-state anesthetic concentrations, or comparable estimates of cerebral concentration, the approximately 40-Hz power could offer advantages for predicting wakeful responsiveness.

The Effects of Ketamine and Rocuronium on the A-Line® Auditory Evoked Potential Index, Bispectral Index, and Spectral Entropy Monitor during Steady State Propofol and Remifentanil Anesthesia

2006 ◽  
Vol 105 (6) ◽  
pp. 1122-1134 ◽  
Author(s):  
Hugo E. M. Vereecke ◽  
Ann L. Vanluchene ◽  
Eric P. Mortier ◽  
Karel Everaert ◽  
Michel M. R. F. Struys
Keyword(s):  
Steady State ◽  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Control Group ◽  
Mean Values ◽  
State Entropy ◽  
Potential Index ◽  
Group Response ◽  
Response Entropy

Background The authors studied the effects of ketamine and rocuronium on the Bispectral Index, A-Line auditory evoked potential index, state entropy, and response entropy during a calculated steady state anesthesia with propofol and remifentanil. Methods After ethics committee approval, 42 patients were allocated to four groups. Baseline measurements were performed after implementing a calculated steady state anesthesia with propofol and remifentanil. The control group received no additional medication. The ketamine group received a bolus and continuous infusion of ketamine. The rocuronium group received a bolus of rocuronium. The rocuronium-ketamine group received both. All data were stored during 15 min after baseline. After inspection of the raw data, the authors conducted an explorative statistical analysis. Results No significant changes were found in the control group for any of the monitors. Mean values decreased in the rocuronium group for the A-Line auditory evoked potential index, Bispectral Index, and response entropy, but not for state entropy. In the ketamine group, the A-Line auditory evoked potential index and Bispectral Index did not change significantly, but state and response entropy increased. In the rocuronium-ketamine group, the A-Line auditory evoked potential index and Bispectral Index did not decrease as found in the rocuronium group. Response and state entropy increased significantly. Conclusions The response of all monitors after ketamine administration is not affected by simultaneous administration of rocuronium. Interpretation of all studied indices must be done cautiously while taking into account the clinical setting during measurement.

scholarly journals Visual Reinforcement Audiometry and Steady-State Auditory Evoked Potential in infants with and without conductive impairment

Revista CEFAC ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Michele Vargas Garcia ◽  
Dayane Domeneghini Didoné ◽  
José Ricardo Gurgel Testa ◽  
Rúbia Soares Bruno ◽  
Marisa Frasson de Azevedo
Keyword(s):  
Steady State ◽  
Evoked Potential ◽  
Bone Conduction ◽  
External Auditory Meatus ◽  
Auditory Evoked Potential ◽  
Control Group ◽  
Genetic Syndrome ◽  
Visual Reinforcement ◽  
Potential Test ◽  
Air Conduction

ABSTRACT Purpose: to compare the findings of minimum levels of answers through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential in infants from six to twelve months, with and without conductive disorder. Methods: sixty children aged six to twelve months were evaluated, 30 presenting conductive disorder, and 30 not presenting it. Children with malformation in the external auditory meatus with neurological alteration and / or genetic syndrome were excluded, as well as patients with sensorineural or mixed hearing loss. The infants were subjected to Visual Reinforcement Audiometry and Steady-State Auditory Evoked Potential evaluation through air and bone conduction on the same day. The results of both assessments were compared and correlated. Results: in the comparison through air conduction, for the group without conductive disorder of the medium ear, the minimum levels of response for 500 and 1000Hz were lower (better thresholds) for Steady-State Auditory Evoked Potential in both ears, and through bone conduction were very similar in all frequencies. Concerning the infants that present conductive disorder, the responses through air conduction were better in all frequencies evaluated when obtained via Steady-State Auditory Evoked Potential test. Through bone conduction, the results were very similar for both groups. Conclusion: it was possible to compare the findings to the minimum levels of response through air and bone conductions between the Visual Reinforcement Audiometry and the Steady-State Auditory Evoked Potential, being that the comparison for bone conduction in both groups presents an equivalence in the results, being very similar. In addition, for the air conduction, in the control group, there was proximity of responses of some frequencies, while the values for the Steady-State Auditory Evoked Potential test were better than the behavioral responses in the conductive disorder group.

Effects of Discrimination Task Difficulty on N1 and P2 Components of Late Auditory Evoked Potential

2004 ◽  
Vol 15 (06) ◽  
pp. 456-461 ◽  
Author(s):  
Jerry L. Cranford ◽  
Amy K. Rothermel ◽  
Letitia Walker ◽  
Andrew Stuart ◽  
Saravanan Elangovan
Keyword(s):  
Auditory Processing ◽  
Task Difficulty ◽  
Discrimination Task ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Objective Evidence ◽  
Tonal Stimuli ◽  
Competing Speech ◽  
Selective Effects

The present study investigated the question of whether, in healthy young listeners, increases in discrimination task difficulty will alter the amplitude of either the N1 or P2 components of the late auditory evoked potential (LAEP). Using a stimulus oddball procedure, listeners discriminated changes in the frequency of ongoing tonal stimuli. On different test runs, task difficulty was manipulated by decreasing the size of the frequency differences and/or adding competing speech babble to the nontest ear. Both stimulus procedures produced significant decreases in P2 amplitude but had no effects on N1 amplitudes. This finding of selective effects on later rather than earlier occurring components of the LAEP provides objective evidence that some forms of auditory processing are mediated at more central levels of the system.

Olfactory Modulation of Steady- State Visual Evoked Potential Topography in Comparison with Differences in Odor Sensitivity

2002 ◽  
Vol 16 (2) ◽  
pp. 71-81 ◽  
Author(s):  
Caroline M. Owen ◽  
John Patterson ◽  
Richard B. Silberstein
Keyword(s):  
Steady State ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Behavioral Responses ◽  
Simultaneous Recording ◽  
Odor Concentration ◽  
Odor Detection ◽  
Detection Response ◽  
Response Groups ◽  
Visual Evoked

Summary Research was undertaken to determine whether olfactory stimulation can alter steady-state visual evoked potential (SSVEP) topography. Odor-air and air-only stimuli were used to determine whether the SSVEP would be altered when odor was present. Comparisons were also made of the topographic activation associated with air and odor stimulation, with the view toward determining whether the revealed topographic activity would differentiate levels of olfactory sensitivity by clearly identifying supra- and subthreshold odor responses. Using a continuous respiration olfactometer (CRO) to precisely deliver an odor or air stimulus synchronously with the natural respiration, air or odor (n-butanol) was randomly delivered into the inspiratory airstream during the simultaneous recording of SSVEPs and subjective behavioral responses. Subjects were placed in groups based on subjective odor detection response: “yes” and “no” detection groups. In comparison to air, SSVEP topography revealed cortical changes in response to odor stimulation for both response groups, with topographic changes evident for those unable to perceive the odor, showing the presence of a subconscious physiological odor detection response. Differences in regional SSVEP topography were shown for those who reported smelling the odor compared with those who remained unaware of the odor. These changes revealed olfactory modulation of SSVEP topography related to odor awareness and sensitivity and therefore odor concentration relative to thresholds.

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