"Yasunori Kotani,Yumiko Kuramoto,Tsukamoto Testuji,Tatsuya Yoshihiro,Yoshimi Ohgami,Yusuke Inoue,Yasutsugu Aihara","The effect of task difficulty on the stimulus-preceding negativity (SPN): fMRI and ERP studies",,"Psychophysiology",,"Vol. 45","  Supplement 1","  S84",2008,Oct.