Spatio-temporal Comparison between ERD/ERS and MRCP-based Movement Prediction

Abstract

In brain-computer interfaces (BCIs) based on electroencephalography (EEG), two distinct types of EEG patterns related to movement have been used for detecting the brain's preparation for voluntary movements: a) event-related patterns in the time domain named movement related cortical potentials (MRCPs) and b) patterns in the frequency domain named event-related desynchronization/synchronization (ERD/ERS). The applicability of those patterns in BCIs is often evaluated by the classification performance. To this end, the known spatio-temporal differences in EEG activity can be of interest, since they might influence the classification performance of the two different patterns. In this paper, we compared the classification performance based on ERD/ERS and MRCP while varying the time point of prediction as well as the used electrode sites. Empirical results were obtained from eight subjects performing voluntary right arm movements. Results show: a) classification based on MRCP is superior compared to ERD/ERS close to the movement onset whereas the opposite results farther away from the movement onset, b) the performance maximum of MRCP is located at central electrodes whereas it is at fronto-central electrodes for ERD/ERS. In summary, the results contribute to a better insight into the spatial and temporal differences between ERD/ERS and MRCP in terms of prediction performance. 219Seeland A., Manca L., Kirchner F. and Kirchner E.. Spatio-temporal Comparison between ERD/ERS and MRCP-based Movement Prediction.

Empirical Comparison of Distributed Source Localization Methods for Single-Trial Detection of Movement Preparation

“…The classification performance evaluates the whole processing chain for movement prediction that consisted of preprocessing (see section 2.2), segmentation, feature extraction based on source localization, and classification. Except the source localization step, similar processing chains were already successfully utilized in former studies (Folgheraiter et al, 2011 ; Seeland et al, 2013 , 2015 ; Kirchner et al, 2014 ; Wöhrle et al, 2014 ; Straube et al, 2015 ). The framework pySPACE (Krell et al, 2013 ) was used for processing and performance computation.…”

A Hybrid FPGA-Based System for EEG- and EMG-Based Online Movement Prediction

“…To predict movements, we process the following physiological signals: MRCP: Both the ERD/ERS and the MRCP have been used to detect movement intentions ( Section 2 ). Since the MRCPs-based movement-prediction is more reliable than the ERD/ERS-based procedure close to the actual movement onset [ 143 ], we choose MRCP for movement prediction in our system. EMG: Similarly, the EMG is used as a signal that indicates an upcoming movement.…”

“…MRCP: Both the ERD/ERS and the MRCP have been used to detect movement intentions ( Section 2 ). Since the MRCPs-based movement-prediction is more reliable than the ERD/ERS-based procedure close to the actual movement onset [ 143 ], we choose MRCP for movement prediction in our system.…”

Brain Symmetry Analysis during the Use of a BCI Based on Motor Imagery for the Control of a Lower-Limb Exoskeleton

“…There are different BCI control paradigms for this kind of devices. The most commonly used are based on external stimuli such as steady-state visually evoked potentials [7] or auditory evoked potentials [8], and those related with real motion or MI such as motionrelated cortical potentials [9][10][11] or ERD/ERS [12][13][14][15][16]. Controlling a BCI with MI can emulate the lost motor function by inducing mechanisms of neuroplasticity [17].…”