The different degree of effects of unattended peripheral information and the possible contribution of reading habit on the central information processing was investigated using a new priming paradigm developed by Ortells and Tudela (1996). In the sequence of the stimulus presentation, the peripheral information were presented both in the left visual field (LVF) and the right visual field (RVF) simultaneously, and after 30 msec, a central target was presented. Subjects were required to be unattentive to the primes, and to make a lexical decision toward the central target. In Experiment 1, the effect of unattended peripheral information in horizontal letter arrangement was measured. Sixteen university students participated in as the subject, and in Experiment 2 the effect in vertical letter arrangement was measured and 2d university students were participated. The results revealed that the unattended peripheral priming effect occurred only in the left hemisphere, and the reading habit affected on this priming effect. Based on these findings, the implication of the unattended peripheral information effect was discussed.

Key Words: hemispheric asymmetry, unattended peripheral priming