Does Automatic Morphological Processing Uniquely Contribute to the Reading Abilities of Middle School Students?

Does Automatic Morphological Processing Uniquely Contribute to the Reading Abilities of Middle School Students?Purpose: Morphological processing is theorized to contribute to skilled reading via the processing of high-level regularities (e.g., semantics). However, morphemes also may contribute to skilled reading via relatively low-level regularities: orthography and phonology. Evidence suggests that middle school marks the shift from effortful use of knowledge of morphological structure during word reading to its automatic activation, thus supporting the development of reading fluency and comprehension. Consequently, this study asked whether automatic morphological processing contributes unique variance to these reading outcomes in middle school students. Method: Participants were 80 seventh- and eighth-grade students (n female = 42, n male = 38; mean age = 12.76 years). Four assessments measured decoding, oral reading fluency, and comprehension. Four computer-administered experimental tasks (each with a masked and unmasked version) indexed automaticity and knowledge in reading morphologically complex and simple words. Three analysis approaches were used in a conceptual replication of previous studies (Roembke et al., 2019; 2021): mixed ANOVAs, commonality analyses, and hierarchical regressions.Results: Only automaticity with morphologically complex words contributed unique variance to comprehension, and it also contributed unique variance to fluency. This was shown on a task that required the mapping of morpho-orthographic to morpho-phonological regularities. Automaticity with morphologically simple words most consistently contributed unique variance to decoding and fluency. Conclusions: Results suggest that middle school students automatically apply morpho-orthographic to morpho-phonological regularities to support fluency and comprehension. However, there was no evidence that they automatically map morpho-orthographic to morpho-semantic regularities to uniquely influence these outcomes.