Influence of attention alternation on movement-related cortical potentials in healthy individuals and stroke patients

- Attention significantly affects detection of the movement related cortical potential (MRCP) from EEG electrode Cz.
- Brain-computer-interfaces should be robust to alterations in the user's attention.
- Attention drift from a movement can be monitored in EEG signals obtained from a single channel.

ObjectiveIn this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution.MethodsEEG signals from Cz and its surrounding channels were recorded during three sets of ankle dorsiflexion movements. Each set was interspersed with either a complex or a simple auditory oddball task for healthy participants and a complex auditory oddball task for stroke patients.ResultsThe amplitude of the movement-related cortical potentials (MRCPs) decreased with the complex oddball paradigm, while MRCP variability increased. Both oddball paradigms increased the detection latency significantly (p < 0.05) and the complex paradigm decreased the true positive rate (TPR) (p = 0.04). In patients, the negativity of the MRCP decreased while pre-phase variability increased, and the detection latency and accuracy deteriorated with attention diversion.ConclusionAttention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method.SignificanceBrain-computer interfaces for neuromodulation that use the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz.