Beyond single syllables: Large-scale modeling of reading aloud with the Connectionist Dual Process (CDP++) model

Conrad Perry, Johannes C. Ziegler, Marco Zorzi

Research output: Contribution to journalArticlepeer-review


Most words in English have more than one syllable, yet the most influential computational models of reading aloud are restricted to processing monosyllabic words. Here, we present CDP++, a new version of the Connectionist Dual Process model (Perry, Ziegler, & Zorzi, 2007). CDP++ is able to simulate the reading aloud of mono- and disyllabic words and nonwords, and learns to assign stress in exactly the same way as it learns to associate graphemes with phonemes. CDP++ is able to simulate the monosyllabic benchmark effects its predecessor could, and therefore shows full backwards compatibility. CDP++ also accounts for a number of novel effects specific to disyllabic words, including the effects of stress regularity and syllable number. In terms of database performance, CDP++ accounts for over 49% of the reaction time variance on items selected from the English Lexicon Project, a very large database of several thousand of words. With its lexicon of over 32,000 words, CDP++ is therefore a notable example of the successful scaling-up of a connectionist model to a size that more realistically approximates the human lexical system.

Original languageEnglish
Pages (from-to)106-151
Number of pages46
JournalCognitive Psychology
Issue number2
Publication statusPublished - Sep 2010


  • Computational modeling
  • Disyllables
  • Reading aloud
  • Word stress

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Neuropsychology and Physiological Psychology
  • Developmental and Educational Psychology
  • Artificial Intelligence
  • Linguistics and Language


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