EEG and ERP Biomarkers, Source Localisation and Neurofeedback for Performance Enhancement in Elite Table Tennis Athletes

Abstract

It was hypothesised that the EEG of elite table tennis players would differ significantly from the amateur players at cortical source engaged in processing vision of a 'virtual opponent' presented in a table tennis video-viewing (VT) task and in ERPs to the two visual-spatial Go-NoGo (vsCPT1/vsCPT4) tasks. Both paradigms were conceptually designed for this research. It was hypothesised that individualized Neurofeedback (NFB) training protocols could be used to train performance in this specific neural circuitry and enhance performance related cognitive skills of elite table tennis athletes.<br/> An original sample of over 200 table tennis players' EEG was recorded in baseline conditions (eyes open, eyes closed), VT and vsCPT, allowing for a comparison between a group of elite table tennis players to a group of lower level but experienced 'amateur' players. Maximal cortical source differences (higher activity in the elite compared to the amateur group) were located by eLORETA at right Brodmann Area (BA) 13 and right BA6 in a narrow frequency band of 10.50 to 11.75 Hz. Source activity was found to be significantly related to superior response speed and perceptual discrimination at the higher processing load (vsCPT4) and reduced response bias at the lower processing load (vsCPT1). Partial least squares analysis showed ERPs during vsCPT accounted for >80% of variance in world rankings of 16 elite athletes.<br/> A NFB protocol was designed using the cortical sources differentiating Elite from Amateur table tennis players. Nineteen nationally ranked players undertook intensive table tennis training, while ten of those players made up the experimental group and also participated in 15 x 30 minute sLoreta-NFB sessions. NFB up-trained EEG source activity at right BA13 and right BA6 within the 10.5-11.5 Hz (upper alpha) band but resulted in a significant decrease in source activity at 11.25Hz in right BA6 post training. Behaviourally, vsCPT results showed improved accuracy to NoGo stimuli.<br/> An adjusted NFB protocol training rightBA40 was then tested. Again, significant post training decreases in source activity resulted, but this time across three conditions (Eyes Open, Eyes Closed and VT). Importantly, pre – post NFB training reduced 9.25 Hz activity during the VT condition and was strongly and significantly correlated with pre – post NFB training increases in NoGo accuracy (vsCPT1). Thus, the changes in cortical activity following this NFB training protocol were directly linked to sport related performance enhancement in this study.