A LITERATURE-REVIEW AND NEW DATA SUPPORTING AN INTERACTIVE ACCOUNT OFLETTER-BY-LETTER READING

We present a theoretical account of letter-by-letter reading (LBL) tha t reconciles discrepant findings associated with this form of acquired dyslexia. We claim that LBL reading is caused by a deficit that affec ts the normal activation of the orthographic representation of the sti mulus. In spite of this lower-level deficit, the degraded orthographic information may be processed further, and lexical, semantic, and high er-order orthographic information may still influence the reading patt erns of these patients. In support of our position, we present a revie w of 57 published cases of LBL reading in which we demonstrate that a peripheral deficit was evident in almost all of the patients and that, simultaneously, strong effects of lexical/semantic variables were obs erved on reading performance. We then go on to report findings from an empirical analysis of seven LBL readers in whom we document the joint effects of lexical variables (word frequency and imageability) and wo rd length on naming latency. We argue that the reading performance of these patients reflects the residual functioning of the same interacti ve system that supported normal reading premorbidly.