Semantic activation, letter search and N400: A reply to Mari-Beffa, Valdes, Cullen, Catena and Houghton (2005)

From a behavioural point of view, the automaticity of semantic activation was denied because letter search eliminates semantic priming effects on RT. From a neuroscience point of view, two recent studies used the N400 to test this claim with antithetic results. Here, we replicate N400 priming effects in the letter search task. The negative results might be traced back to the use of an inappropriate reference electrode. Thus, the theory of semantic activation being an automatic process should not be abandoned prematurely.