Topographic measures of cerebral activity during reading of text at fast- and slow-paced rates.

Eight college level readers were given short paragraphs for reading, presented on a computer terminal in units of 2 or 3 words at a time. Two conditions were presented, a fast reading session with an inter-stimulus interval (ISI) of 1.1 seconds, and a slower session with an ISI of 1.2 seconds. EEG and ERP measures were obtained. ERP findings revealed a late central-posterior negativity which was sensitive to the effect of varying ISI by showing shorter latencies, of about 110 msec, to the smaller interval. An earlier component complex consisting of a bi-temporal-occipital negativity and frontal positivity was observed between 155 and 175 msec. This component was not observed to be sensitive to variation of ISI. Analysis of the unaveraged EEG activity by FFT and absolute power measures revealed that the activity was primarily slow wave (0-7.5 HZ), and right-sided. Findings suggested that the brain functions as an integrated whole during reading, activating a diffuse set of neural generators.