EEG correlates of cerebral engagement in reading tasks

This study evaluated the utility of electroencephalographic (EEG) measures as indices of regional cerebral engagement activation during reading in neu rologically intact adult volunteers. EEG was recorded from 16 scalp locatio ns as participants performed four visual detection tasks designed to tap in to increasingly more complex operations regularly involved in reading, name ly visual-spatial, orthographic, phonological, and semantic. EEG records we re quantified using power spectrum measures in four frequency bands (delta, theta, alpha, beta1, and beta2), in addition to a non-linear estimate of s ignal complexity (prediction error). Results showed that (2) changes in spe ctral power between pairs of reading tasks, and (2) regional Variations in EEG measures for each task, were restricted to signals recorded over the le ft hemisphere. These findings are in agreement with knowledge regarding lef t hemisphere involvement in higher level component processes of reading.