Interacting Processes in the Development of Printed Word Recognition

There are two major requirements which a good theory of the development of the ability to recognise printed words must fulfil: first, it must accurately describe the processes of development, and second, it must culminate in a processing model which is compatible with what is now known, from studies of normal and abnormal processing in adults, about printed word recognition processes in skilled and formerly skilled readers. In this chapter we consider recent advances in understanding of both the development and the skilled use of printed word recognition processes, describe an experiment designed to elucidate interaction between word level and sub­ word level processes, and discuss how best our experimental findings might be accommodated in a developmental theory which fulfils both the requirements established above. We then outline some of the implications of recent theoretical developments for teaching practice. The dual-route model of how printed word recognition is accomplished by skilled readers (e.g., Coltheart, 1978) proposes two underlying cognitive processing systems. In the lexical system, letter detectors give access to stored representations of whole words, allowing retrieval of their meanings and pronunciations. In the sublexical system, letter detectors give access to stored rules governing segmented print-to-sound correspondences, allow­ ing any printed string to be translated to sound, with meaning retrieved from the pronunciation obtained. According to dual route theory the lex­ ical and sublexical systems operate independently but in parallel in the skilled reader. The systems have been shown to be dissociable in studies of patients who have suffered brain injury in adulthood which has resulted in reading impairment. Single-case studies of these patients have demon­ strated patterns of selective impairment of word recognition skills. One criticism frequently levelled at attempts to adopt this early ver­ sion of the dual route model as a framework within which to consider the * We acknowledge the support ofESRC Grant R000234380 in enabling the work described in this chapter.