Single-Trial Normalization for Event-Related Spectral Decomposition Reduces Sensitivity to Noisy Trials

By Romain Grandchamp, Arnaud Delorme. Front. Psychology, 2011

353 citations recorded by the source corpus.

In electroencephalography, the classical event-related potential model often proves to be a limited method to study complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as event-related spectral perturbation (ERSP) – and its variant event-related synchronization and event-related desynchronization – have been used over the past 20 years. They represent average spectral changes in response to a stimulus. These spectral methods do not have strong consensus for comparing pre- and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial-based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time–frequency responses and behavior compared to classical ERSP methods.

Subfields: Cognitive Neuroscience, Signal Processing

View Paper: https://www.semanticscholar.org/paper/4451a9d792d4d5b992a80d69395d5ffe31e7d260

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Citations in the corpus

Theta oscillations between the ventromedial prefrontal cortex and amygdala support dynamic representations of threat and safety (2025, unknown): “Each epoch was baseline corrected (-2 to -1 s before CS onset to avoid smearing of changes in theta power between pre-and post-CS time bins) using full-epoch length single-trial corrections (Grandchamp & Delorme, 2011).”
Electrocorticography to Investigate Age-Related Brain Lateralization on Pediatric Motor Inhibition (2022, methodology): “In this study, we used the baseline-normalized event-related spectral perturbation (ERSP) (41) to determine the activation of ECoG data under the NoGo trial.”
The strength of anticipated distractors shapes EEG alpha and theta oscillations in a Working Memory task (2024, methodology): “These representations were normalized using the rest interval between -1 and 0 s as baseline (Grandchamp and Delorme, 2011); specifically we computed the difference between the power at each time-frequency point and the average baseline power at the same frequency (i.e., the mean power value…”
Stress enhances emotional memory-related theta oscillations in the medial temporal lobe (2021, background): “The single trials were log-transformed (Grandchamp and Delorme, 2011; Smulders et al., 2018) and baseline corrected (absolute baseline correction − 1 to 0 s relative to stimulus onset).”