Auditory brainstem and middle latency responses recorded at fast rates with randomized stimulation

Abstract

Randomized stimulation and averaging (RSA) allows auditory evoked potentials (AEPs) to be recorded at high stimulation rates. This method does not perform deconvolution and must therefore deal with interference derived from overlapping transient evoked responses. This paper analyzes the effects of this interference on auditory brainstem responses (ABRs) and middle latency responses (MLRs) recorded at rates of up to 300 and 125 Hz, respectively, with randomized stimulation sequences of a jitter both greater and shorter than the dominant period of the ABR/MLR components. Additionally, this paper presents an advanced approach for RSA [iterative-randomized stimulation and averaging (I-RSA)], which includes the removal of the interference associated with overlapping responses through an iterative process in the time domain. Experimental results show that (a) RSA can be efficiently used in the recording of AEPs when the jitter of the stimulation sequence is greater than the dominant period of the AEP components, and (b) I-RSA maintains all the advantages of RSA and is not constrained by the restriction of a minimum jitter. The significance of the results of this study is discussed.

Improved Transient Response Estimations in Predicting 40 Hz Auditory Steady-State Response Using Deconvolution Methods

“…The latencies of all three wave-components from both 40 Hz AEPs are prolonged relatively to the latencies of these components in tAEP. Such a phenomenon is in agreement with the previous report that the latencies of AEP components at high stimulation rates (i.e., 40 Hz) are generally longer than those at low stimulation rates (Ozdamar et al, 2007 ; Valderrama et al, 2014a ). Moreover, statistically significant differences are observed in amplitude variations, which can be examined in difference waveforms (red dotted curves).…”

“…Similar variation can be also observed in Ozdamar et al ( 2007 ) and in Holt and Ozdamar ( 2015 ), where they failed to find a consistent Pb resonance at 40 Hz. Using a different deconvolution method and stimulus sequences, Valderrama et al ( 2014a ) reported that the amplitude of the NbPb complex initially declined when the click-stimulus rate increased from 8 to 20 Hz, then enhanced from 20 to 67 Hz, and reduced again from 67 to 125 Hz. In addition, Valderrama et al ( 2014b ) also reported that ABR may be affected by the ISI distribution in a jittered sequence, which was assumed to be related to the slow mechanism of adaptation (LeMasurier and Gillespie, 2005 ; Zhang et al, 2007 ).…”

The Parallel Auditory Brainstem Response

“…Relevant ABR components can have latencies of 12–15 ms, which practically limits the rate to 70–80 Hz. Several studies have sidestepped this constraint by replacing periodic stimulus timing with various types of jitter or randomization schemes, allowing stimulation rates into the high hundreds of hertz or beyond (Eysholdt & Schreiner, 1982; Özdamar & Bohórquez, 2006; Valderrama et al., 2012, 2014; Wang, Zhan, Yan, Bohórquez, & Özdamar, 2013). These high rates reduce noise, but neural adaptation shrinks responses (i.e., signal), which in turn partially or completely cancels out SNR gains that the faster rates might have provided.…”

A flexible and inexpensive high-performance auditory evoked response recording system appropriate for research purposes

“…Some of the results obtained in these experiments, such as the ABR signal obtained at 250 Hz and the MLR signal recorded at 125 Hz (experiments 4 and 5), are especially remarkable. In addition to these experiments, the AER recording system proposed in this article has been proved to be effective in several previous studies, e.g., this architecture was used (a) to develop the RSA method and compare its performance with the QSD technique through ABR signals recorded from eight subjects at different stimulation rates [28]; (b) to study the fast and slow mechanisms of adaptation in humans by analyzing the morphology of ABR signals obtained with the separated responses methodology [30,35]; (c) to develop and evaluate different approaches to automatic quality assessment and response detection methods [31,34,37]; (d) to conduct a study to test whether or not high stimulation rates could save recording time [29,36]; (e) to analyse the effects of adaptation and deconvolution of ABR and MLR signals with RSA [32]; and (f) to develop a method that allows the deconvolution of overlapping responses with randomized stimulation using frequency domain-based artifact rejection methods [33]. The results of the experiments, along with the results obtained in the aforementioned studies [28][29][30][31][32][33][34][35][36][37], indicate that the AER recording system described in this article can be efficiently used to record ABR and MLR signals under different recording conditions.…”

“…This system was used to develop (a) the RSA method, a technique that allows the recording of Brought to you by | Simon Fraser University Authenticated Download Date | 6/6/15 4:11 PM AER at high rates [28]; (b) the separated response method, which allowed for the first time the study of the fast and slow mechanisms of adaptation in humans [30,35]; (c) the fitted parametric peaks method, which provides an automatic evaluation of the quality of ABR signals and a parameterization of the most important waves in terms of amplitude, latency, and width [31,34]; (e) studies to test whether or not high stimulation rates could save recording time [29,36]; (f) an automatic auditory response detection paradigm based on response tracking [37]; (g) a study of the effects of averaging and deconvolution in ABR and MLR signals using the RSA method [32]; and (h) a deconvolution method based on randomized stimulation using artifact rejection methods in the frequency domain [33].…”