The DRC model is a computational model of reading which is intended to explain how skilled readers perform certain basic reading tasks. The acronym emphasizes the two fundamental properties of the model: it is a Dual Route model, and within the model information processing occurs in a Cascaded fashion¹.

The model consists of three routes, the lexical semantic route², the lexical nonsemantic route, and the GPC route. Each route is composed of a number of interacting layers. These layers contain sets of units. The units represent the smallest individual symbolic parts of the model, such as words in the orthographic lexicon or letters in the letter unit layer.

There are two ways in which the units of different layers interact. One is through inhibition, where the activation of a unit makes it more difficult for the activation of other units to rise. The other is through excitation, where the activation of a unit contributes to the activation of other units. Units may also interact on the same level through lateral inhibition.

The 2001 Psychological Review paper on DRC can be downloaded here (9.1MB pdf).

A simulator for DRC has been developed and is available for Mac OS X, Linux (x86) and Windows. Documentation for the simulator is currently being developed. The following documentation is currently available:

Writing DRC Batch Files
Understanding DRC's Output

If you are having difficulties with DRC, or just have a question, try the Frequently Asked Questions page.

DRC is still in development. The latest publically available version of DRC is version 1.1.4 (Model version 1.1.4) released on the 17th of January, 2006.

DRCView is a Mac OS X tool for visualising the activation files generated by the DRC simulator. Charts generated by DRCView can be exported in JPEG and Quicktime Movie (example) format for use in presentations and papers.

The latest version of DRCView is version 0.5, released on February 23rd, 2006.

   

Some other resources related to DRC and reading.

University of Ottawa - Omnilex Database
The ARC Nonword Database
Max's DRC Page

This list is still under construction. We currently have 12 papers relevant to DRC listed. If you know of any other relevant papers please let us know.

Click on a title to see more information about that paper.

Coltheart, M., Rastle, K., Perry, C., Langdon, R. & Ziegler, J. DRC: A Dual Route Cascaded model of visual word recognition and reading aloud. Psychological Review, 2001, 108, 204-256.

Rastle, K. and Coltheart, M. Serial processing in reading aloud: Reply to Zorzi (2000). Journal of Experimental Psychology: Human Perception & Performance, 2000, 26, 1232-1235.

Rastle, K., Harrington, J.M., Coltheart, M. and Palethorpe, S. Reading aloud begins when the computation of phonology is complete. Journal of Experimental Psychology: Human Perception & Performance, 2000, 26, 1178-1191.

Rastle, K. and Coltheart, M. Lexical and nonlexical print-to-sound translation of disyllabic words and nonwords. Journal of Memory & Language, 2000, 42, 342-364.

Cestnick, L. and Coltheart, M. The relationship between language-processing and visual-processing deficits in developmental dyslexia. Cognition, 1999, 71, 231-255.

Rastle, K. and Coltheart, M. Serial and strategic effects in reading aloud. Journal of Experimental Psychology: Human Perception & Performance, 1999, 25, 482-503.

Rastle, K. and Coltheart, M. Lexical and nonlexical phonological priming in reading aloud. Journal of Experimental Psychology: Human Perception & Performance, 1999, 25, 461-481.

Coltheart, M., Woollams, A., Kinoshita, S. and Perry, C. A position-sensitive Stroop effect: Further evidence for a left-to-right component in print-to-speech. Psychonomic Bulletin & Review, 1999, 6, 456-463.

Rastle, K and Coltheart, M. Whammies and double whammies: The effect of length on nonword reading. Psychonomic Bulletin & Review, 1998, 5, 277-282.

Coltheart, M. and Leahy, J. Assessment of lexical and nonlexical reading abilities in children: Some normative data. Australian Journal of Psychology, 1996, 48, 136-140.

Coltheart, M., Langdon, R. and Haller, M. Computational cognitive neuropsychology. In Dodd B, Worrall L and Campbell R (eds). Evaluating Theories of Language: Evidence from Disordered Communication. London: Whurr Publishers, 1996.

Coltheart, M. and Rastle, K. Serial Processing in Reading Aloud: Evidence for Dual-Route Models of Reading. Journal of Experimental Psychology: Human Perception and Performance, 1994, 20, 1197-1211.

1. Coltheart, M., Rastle, K., Perry, C., Langdon, R. & Ziegler, J. DRC: A Dual Route Cascaded model of visual word recognition and reading aloud. Psychological Review, 2001, 108, 204 - 256.

2. As yet, the semantic part of the model has not been implemented.