“…Over the past two decades, theoretical accounts of NP have flourished e.g., the distractor-inhibition model (Houghton and Tipper, 1994 ), the episodic memory retrieval model (Neill and Valdes, 1992 ; Frings et al, 2007 ), temporal discrimination model (Milliken et al, 1998 ), the dual-mechanism hypothesis (May et al, 1995 ), and the computational imago-semantic action model (CISAM) (Schrobsdorff et al, 2007 ), but these theories remain controversial (Kane et al, 1997 ; Tipper, 2001 ; Grison et al, 2005a , b ). This lack of consensus results not only from individual differences depend on demographics [age (Gamboz et al, 2002 ), sex (Bermeitinger et al, 2008 ), and neuropsychiatric disorders (Ungar et al, 2010 )], but also from the complexity of the stimuli combinations in NP; the NP effect depends on subtle experimental parameters such as inter-stimulus time intervals, and various stimulus combinations within NP may represent different degrees of inhibition.…”