Wavelet packet-based independent component analysis for feature extraction from motor imagery EEG of complex movements

► This study developed a wavelet packet-based independent component analysis (WPICA) method to extract the event-related de-synchronisation and synchronisation (ERD/ERS) patterns in different frequency bands during complex motor imagery of lower limb action. ► The criterion for principal independent component selection and the procedures of the WPICA method were demonstrated. ► The performance of the WPICA method was assessed by comparison with the traditional ICA method.