Breaking boundaries: Letter transpositions and morphological processing

We tested the predictions of a dual-route model of complex word reading according to which morpho-orthographic segmentation is hypothesised to require a fine-grained orthographic code that would be particularly sensitive to letter order, whereas morphosemantic representations are hypothesised to be most rapidly accessed via a coarsegrained orthographic code that is less sensitive to letter order. We predicted that letter transpositions would disrupt morpho-orthographic processing more than morphosemantic processing. In line with these predictions, Experiment 1 showed no priming from opaque pseudo-derived primes containing a letter transposition at the morpheme boundary (masetr-mast) relative to replaced letter controls (masicr-mast) in the presence of significant priming from transposed-letter transparent derived primes (banekr-bank). Similarly, Experiment 2 showed that although complex nonword primes (bankity-bank) generate significant priming effects relative to unrelated primes (farmity-bank), the same primes with letter transpositions (banikty-bank) do not prime relative to transposed unrelated primes (farimty-bank).