When 'slime' becomes 'smile': Developmental letter position dyslexia in English

Saskia Kohnen, Lyndsey Nickels, Anne Castles, Naama Friedmann, Genevieve McArthur

Research output: Contribution to journalArticlepeer-review


We report the first three cases of selective developmental letter position dyslexia in English. Although the parents and teachers of the children were concerned about these children's reading, standard tests did not reveal their deficit. It was only when the appropriate target words were presented, in this case, migratable words, that their letter position dyslexia was detected. Whereas previous research has described cases with acquired and developmental forms of letter position dyslexia in Hebrew and Arabic readers, this is the first report of this type of reading disorder in English. The cardinal symptom of letter position dyslexia is the migration of letters within the word (reading slime as 'smile'; pirates as 'parties'). These migration errors occur in reading aloud as well as in tasks of silent reading. This study provides further evidence that migration errors emerge at the level of early visual-orthographic analysis, in the letter position encoding function. Alternative explanations for the occurrence of migration errors such as poor phonological processing or a deficit in the orthographic input lexicon are ruled out.

Original languageEnglish
Pages (from-to)3681-3692
Number of pages12
Issue number14
StatePublished - Dec 2012


  • Developmental dyslexia
  • Letter position coding
  • Lexical capture
  • Transposed letter nonwords
  • Transposed letter words

All Science Journal Classification (ASJC) codes

  • Experimental and Cognitive Psychology
  • Cognitive Neuroscience
  • Behavioral Neuroscience


Dive into the research topics of 'When 'slime' becomes 'smile': Developmental letter position dyslexia in English'. Together they form a unique fingerprint.

Cite this