PUB - Publikationen an der Universität Bielefeld

In masked priming experiments that require categorisation responses, typically responses are faster when the prime and the target are members of the same category, e.g. in number magnitude estimation (Dehaene et al., 1998). However, previous research has not shown response congruence priming in lexical decision (Norris & Kinoshita, 2008; Perea, Fernández, & Rosa, 1998). This finding is somewhat surprising as lexical activity due to the prime might be expected to bias lexical decisions. Nevertheless, the predictions by the Bayesian Reader model (Norris & Kinoshita, 2008) are confirmed. In recent work (Loth & Davis, 2010), we have conducted a series of experiments that demonstrate clear response congruency effects in masked primed lexical decision. The data show that the size of the response congruency effect is influenced by the difficulty of the word-nonword discrimination. This sensitivity can explain the failure to find response congruency effects in previous studies. Simulations of the experiments using the Bayesian Reader model indicate that the model cannot predict these effects. The spatial coding model (Davis, 2010) predicts response congruency effects for nonword targets, but not for word targets. The simplifying assumption of homogeneous inhibition which was adopted from the original interactive activation model can be replaced by the assumption of nonhomogeneous lateral inhibition. In this account lateral inhibition is restricted to orthographically similar words (e.g., cat inhibits cot, but not boy; (Davis, 1999)). Modifying the spatial coding model to implement nonhomogeneous lateral inhibition enabled it to provide a better fit to the data.