Continuous repetition of a word causes listeners to hear the word transform into other utterances, an illusion known as the verbal transformation effect. Node structure theory (MacKay, 1987) provides a useful framework for understanding the illusion, positing that the transformations listeners report are a function of the stability of the node that represents the repeating stimulus. In Experiment 1, the accuracy of this account was investigated, using stimuli that varied from words to phonotactically illegal pseudowords. Experiments 2 and 3 replicated and generalized the findings of Experiment 1, which support a conceptualization of node stability slightly different from that embodied in node structure theory. A new method of measuring lexical influences in the verbal transformation effect is also introduced.