Phonological deficits in developmental dyslexia in a psycholinguistic framework: unguided phonological encoding

Developmental dyslexia (DD) is associated with phonological deficits. In this article, we will discuss the phonological deficits occurring in DD by applying psycholinguistic models of speech production (Levelt et al., 1999; Dell, 1986). According to these models, output phonology is created through a process called phonological encoding, which operates in a close relationship with internal speech monitoring. We will argue that in decoding (reading by using letter-sound correspondences instead of whole word recognition) phonological word-forms are assembled within the speech output system by utilising phonological encoding and, more specifically, through a process that we call unguided phonological encoding. In this process, encoding is done in a piece-by-piece fashion without access to an active word-form, which means that internal speech monitoring cannot function in a normal manner. This makes the process less regulated and more prone to difficulties. We argue that DD is related to difficulties in unguided phonological encoding. We will consider the implications of our theoretical hypotheses, first, from a clinical perspective by providing a qualitative description of typical blending difficulties among children with DD at our clinic. Second, we will discuss earlier research literature on DD by focusing on how difficulties in unguided phonological encoding could explain the widely researched features of DD. Finally, we will outline a few possibilities for how our theoretical hypotheses could be tested. We suggest that the focus on the interplay between phonological encoding and internal speech monitoring provides a framework with which we can ask new questions about the phonological difficulties associated with DD.