Are There Separate Neural Systems for Spelling? New Insights into the Role of Rules and Memory in Spelling from Functional Magnetic Resonance Imaging.

How do people spell the thousands of words at the tips of their tongues? Are words with regular sound-to-letter correspondences (e.g., "blink") spelled using the same neural systems as those with irregular correspondences (e.g., "yacht")? By offering novel neuroimaging evidence, we aim to advance contemporary debate about whether people use a single lexical memory process or whether dual mechanisms of lexical memory and sublexical phonological rules work in concert. We further aim to advance understanding of how people read by taking a fresh look at the related yet distinct capacity to spell. During functional magnetic resonance imaging scanning, 12 participants heard low-frequency regular words, irregular words, and nonwords (e.g., "shelm") and responded whether a visual presentation of the word was spelled correctly or incorrectly. While behavioral measures suggested some differences in accuracy and reaction time for the different word types, the neuroimaging results alone demonstrated robust differential processing and support a dual-route model of spelling, with implications for how spelling is taught and remediated in clinical and educational contexts.