Combined EEG/EMG evaluation during a novel dual task paradigm for gait analysis

Abstract

Little knowledge is available about neural dynamics during natural motor behavior and its perturbation in aging and neurological diseases. In the present study, we aim to evaluate electroencephalography-electromyography (EEG-EMG) co-registration features of rest and walking in basal condition and under cognitive tasks in normal subjects to characterize a “normal gait” and to define the possible paradigm to detect abnormal behavior. We realized EEG-EMG co-registration in 17 healthy subjects in different conditions: 1) sitting, 2) standing 3) walking. A P300 oddball paradigm was performed during 4) standing condition and 5) during walking. We found that the P300 component amplitude increases during physical activity. The negative correlation between age and P300 component vanishes during gait. The spectral width of the total alpha rhythm appears reduced in the course of P300 in a static situation, with likely phenomena of desynchronization related to cognitive task. During gait, the activity is canceled, suggesting a state of "idling" of cortical areas previously involved in the process of recognition of the target stimulus. Additionally, EMG co-contraction and μ-rhythm desynchronization (μ-ERDs) are also analyzed using wireless equipment. It is demonstrated the EMG co-contraction validity, showing the possibility to discern a normal gait (tot. steps: 60; max co-contraction time: 100ms; average: 20ms) from a perturbed one (tot. steps: 60; max co-contraction time: 260ms; mean: 70ms). μ-ERDs were detected in about 60% of the analyzed steps, showing medium variations in μ - power of about -2.4.