New metric for optimizing Continuous Loop Averaging Deconvolution (CLAD) sequences under the 1/f noise model

Abstract

Continuous loop averaging deconvolution (CLAD) is one of the proven methods for recovering transient auditory evoked potentials (AEPs) in rapid stimulation paradigms, which requires an elaborated stimulus sequence design to attenuate impacts from noise in data. The present study aimed to develop a new metric in gauging a CLAD sequence in terms of noise gain factor (NGF), which has been proposed previously but with less effectiveness in the presence of pink (1/f) noise. We derived the new metric by explicitly introducing the 1/f model into the proposed time-continuous sequence. We selected several representative CLAD sequences to test their noise property on typical EEG recordings, as well as on five real CLAD electroencephalogram (EEG) recordings to retrieve the middle latency responses. We also demonstrated the merit of the new metric in generating and quantifying optimized sequences using a classic genetic algorithm. The new metric shows evident improvements in measuring actual noise gains at different frequencies, and better performance than the original NGF in various aspects. The new metric is a generalized NGF measurement that can better quantify the performance of a CLAD sequence, and provide a more efficient mean of generating CLAD sequences via the incorporation with optimization algorithms. The present study can facilitate the specific application of CLAD paradigm with desired sequences in the clinic.

A Review of the Role of Auditory Evoked Potentials in Mild Traumatic Brain Injury Assessment

“…The main challenge will be to attenuate the influence of noise during data acquisition resulting from higher stimulus repetition rates (more than 100 stimuli per second). Algorithm-based novel techniques such as continuous loop averaging deconvolution and maximum length sequencing have been used to suppress noise and recover transient AEPs from the data (Peng, Yuan, Chen, Wang, & Ding, 2017). Lastly, investigating the potential influence of different types of auditory stimuli like clicks and tone bursts (frequency specific stimuli) at various presentation rates and levels will offer new insights into understanding deficits in central and peripheral auditory pathways of people with mTBI.…”