Abstract
Speed of information processing (e.g., how quickly letter identity and position is processed) plays an important role in reading. Previous study showed a positive correlation between processing speed of letter recognition and RSVP (rapid serial visual presentation) reading speed in people with central-vision loss (Cheong et al., 2007). When training these patients using RSVP reading task (Nguyen et al., 2011), increased reading speed was found to be correlated with reduced fixation duration. It is possible that faster temporal processing of letter recognition underlies the learning induced by RSVP reading training. To evaluate this hypothesis, we trained seven normally-sighted young adults using RSVP reading task at 10° in the lower visual field on five consecutive days. Each training session contains 130 sentences presented at five different speeds (46 to 732 words/minute). Before and after the training, RSVP reading speed, the size of visual span, and threshold duration for crowded letter recognition were measured at 10° above and below fixation. When comparing post- and pre-test performance, we found significant improvements in RSVP reading speed (90%) and temporal processing speed of crowded letter recognition (a reduction of 84ms in threshold duration) while the change in visual-span size was minimal. As expected, the post-pre ratio of temporal processing speed explained about 50% of the variance of the post-pre ratio of RSVP reading speed at the trained location (r = 0.69, p = 0.045). Learning also transferred to the untrained (upper) visual field. Our results confirmed the association between the improvement in reading speed and the increase of temporal processing speed in letter recognition. Training paradigm aiming to boost the speed of information processing may be more effective than the one focusing on improving spatial information processing.
Acknowledgement: EY025658