Is reading automatic? Are the ERP correlates of masked priming really lexical?

Abstract

Humans have an almost unbounded ability to adapt their behaviour to perform different tasks. In the laboratory, this flexibility is sometimes viewed as a nuisance factor that prevents access to the underlying cognitive mechanisms of interest. For example, in order to study "automatic" lexical processing, psycholinguists have used masked priming or evoked potentials. However, the pattern of masked priming can be radically altered by changing the task. In lexical decision, priming is observed for words but not for nonwords, yet in a same-different matching task, priming is observed for same responses but not for different responses, regardless of whether the target is a word or a nonword [Norris & Kinoshita, 2008. Perception as evidence accumulation and Bayesian inference: Insights from masked priming. Journal of Experimental Psychology: General, 137(3), 434-55. doi:10.1037/a0012799]. Here we show that evoked potentials are equally sensitive to the nature of required decision, with the neural activity normally associated with lexical processing being seen for both words and nonwords on same trials, and for neither on different trials.