RETRACTED: Simple mental arithmetic is not so simple: An ERP study of the split and odd-even effects in mental arithmetic

The article substantially duplicates, without citation, results published in Chinese in Acta Psychol. Sinica, 43 (2011) 384-395, http://dx.doi.org/10.3724/SP.J.1041.2011.00384.The Authors wish to apologize to readers for their error.