Is morphological decomposition limited to low-frequency words?

On the basis of data from masked priming experiments, it has been argued that an automatic process of decomposition is applied to all morphologically structured stimuli, irrespective of their lexical characteristics (Rastle, Davis, & New, 2004). So far, this claim has been tested only with respect to low-frequency primes and nonword primes. This is a limitation because some models of morphological processing postulate that only high-frequency complex words are recognized as whole forms. Thus, a more stringent test would be to determine whether high-frequency complex words also show evidence of masked priming. We report an experiment that compares masked-priming effects observed when the primes constitute morphologically structured nonwords (e.g., alarmer-ALARM), low-frequency words with a mean frequency of 2 per million (e.g., notional-NOTION), and high-frequency words with a mean frequency of 60 per million (e.g., national-NATION). These three conditions yielded significant and equivalent effects, lending strong support to the notion of a routine form of decomposition that is applied to all morphologically structured stimuli.