The eye movements of pure alexic patients during reading and nonreading tasks

We compared the eye-movements of two patients who read letter-by-letter (LB L) following a left occipital lobe lesion with those of normal control subj ects and of hemianopic patients in two tasks. a nonreading visual search ta sk and a text reading task. Whereas the LBL readers exhibited similar eye-m ovement patterns to those of the other two groups on the nonreading task, t heir eye movements differed significantly during reading, as reflected in t he disproportionate increase in the number and duration of fixations per wo rd and in the regressive saccades per word. Importantly, relative to the tw o control groups, letter-by-letter readers also made more fixations: per wo rd as word length increased, especially as word frequency and word imageabi lity decreased. Two critical results emerged From these experiments: First, the alteration in the oculomotor behavior of the LBL renders during readin g is similar to that seen in normal readers under difficult reading conditi ons,. as well as in beginning readers and in those with developmental dysle xia, and appears to reflect difficulties in processing the visual stimulus. Second. the interaction of length with frequency and with imageability in determining the eye movement pattern is consistent with an interactive acti vation model of normal word recognition in which weakened activation of ort hographic input can nevertheless engage high-level lexical factors. (C) 200 1 Elsevier Science Ltd. All rights reserved.