Non-negative matrix factorization Vs. FastICA on mismatch negativity of children
Fengyu Cong, Z. Zhang, Igor Kalyakin, Tiina Huttunen-Scott, Heikki Lyytinen, Tapani Ristaniemi · 2009
In this presentation two event-related potentials, mismatch negativity (MMN) and P3a, are extracted from EEG by non-negative matrix factorization (NMF) simultaneously. Typically MMN recordings show a mixture of MMN, P3a, and responses to repeated standard stimuli. NMF may release the source independence assumption and data length limitations required by fast independent component analysis (FastICA). Thus, in theory NMF could reach better separation of the responses. In the current experiment MMN was elicited by auditory duration deviations in 102 children. NMF was performed on the time-frequency representation of the raw data to estimate sources. Support to absence ratio (SAR) of the MMN component was utilized to evaluate the performance of NMF and FastICA. To the raw data, FastICA-MMN component, and NMF-MMN component, SARs were 31, 34 and 49 dB respectively. NMF outperformed FastICA by 15 dB. This study also demonstrates that children with reading disability have larger P3a than control children under NMF.