English-language text is almost always written horizontally. Text can be formatted to run vertically, but this is seldom used. Several studies have found that horizontal text can be read faster than vertical text in the central visual field. No studies have investigated the peripheral visual field. Studies have also concluded that training can improve reading speed in the peripheral visual field for horizontal text. We aimed to establish whether the horizontal vertical differences are maintained and if training can improve vertical reading in the peripheral visual field.
Eight normally sighted young adults participated in the first study. Rapid serial visual presentation (RSVP) reading speed was measured for horizontal and vertical text in the central visual field and at 10 degrees eccentricity in the upper or lower (horizontal text) and right or left (vertical text) visual fields. Twenty-one normally sighted young adults split equally between two training groups and one control group participated in the second study. Training consisted of RSVP reading using either vertical text in the left visual field or horizontal text in the inferior visual field. Subjects trained daily over 4 days. Pre- and post- horizontal and vertical RSVP reading speeds were carried out for all groups. For the training groups, these measurements were repeated 1 week and 1 month posttraining.
Before training, RSVP reading speeds were faster for horizontal text in the central and peripheral visual fields when compared with vertical text. Training vertical reading improved vertical reading speeds by an average factor of 2.8. There was partial transfer of training to the opposite (right) hemifield. The training effects were retained for up to a month.
Rapid serial visual presentation training can improve RSVP vertical text reading in peripheral vision. These findings may have implications for patients with macular degeneration or hemianopic field loss.