# Prestimulus EEG Oscillations and Pink Noise Affect Go/No-Go ERPs

## TL;DR

This study explores how brain activity before a task affects responses during a Go/No-Go task, using novel methods to separate noise from meaningful brain signals.

## Contribution

The paper introduces a novel method to isolate noise-free brain oscillations and explores their impact on ERP components.

## Key findings

- Alpha and beta prestimulus oscillations predict Go ERP components like N2c, P3b, and SW1.
- Pink noise affects No-Go ERP components N1b and N1c, aiding early stimulus identification.
- Noise-free oscillations influence ERP components, which in turn affect task performance.

## Abstract

This study builds on the early brain dynamics work of Erol Başar, focusing on the human electroencephalogram (EEG) in relation to the generation of event-related potentials (ERPs) and behaviour. Scalp EEG contains not only oscillations but non-wave noise elements that may not relate to functional brain activity. These require identification and removal before the true impacts of brain oscillations can be assessed. We examined EEG/ERP/behaviour linkages in young adults during an auditory equiprobable Go/No-Go task. Forty-seven university students participated while continuous EEG was recorded. Using the PaWNextra algorithm, valid estimates of pink noise (PN) and white noise (WN) were obtained from each participant’s prestimulus EEG spectra; within-participant subtraction revealed noise-free oscillation spectra. Frequency principal component analysis (f-PCA) was used to obtain noise-free frequency oscillation components. Go and No=Go ERPs were obtained from the poststimulus EEG, and separate temporal (t)-PCAs obtained their components. Exploratory multiple regression found that alpha and beta prestimulus oscillations predicted Go N2c, P3b, and SW1 ERP components related to the imperative Go response, while PN impacted No-Go N1b and N1c, facilitating early processing and identification of the No-Go stimulus. There were no direct effects of prestimulus EEG measures on behaviour, but the EEG-affected Go N2c and P3b ERPs impacted Go performance measures. These outcomes, derived via our mix of novel methodologies, encourage further research into natural frequency components in the noise-free oscillations immediately prestimulus, and how these affect task ERP components and behaviour.