Orthographic processing: A 'mid-level' vision of reading: The 44th Sir Frederic Bartlett Lecture.

I will describe how orthographic processing acts as a central interface between visual and linguistic processing during reading, and as such can be considered to be the 'mid-level vision' of reading research. In order to make this case, I first summarize the evidence in favour of letter-based word recognition before examining work investigating how orthographic similarities among words influence single word reading. I describe how evidence gradually accumulated against traditional measures of orthographic similarity and the associated theories of orthographic processing, forcing a reconsideration of how letter-position information is represented by skilled readers. Then, I present the theoretical framework that was developed to explain these findings, with a focus on the distinction between location-specific and location-invariant orthographic representations. Finally, I describe work extending this theoretical framework in two main directions: first, to the realm of reading development, with the aim to specify the key changes in the processing of letters and letter strings that accompany successful learning to read, and second, to the realm of sentence reading, in order to specify how orthographic information can be processed across several words in parallel, and how skilled readers keep track of which letters belong to which words.