The effects of word orientation and imageability on visual half-field presentations with a lexical decision task.

Two studies examined the effects of word orientation and word imageability in a visual half-field procedure. The studies involved a lexical decision task in which items were presented in either a horizontal or vertical orientation randomly intermixed in Experiment 1 and blocked in Experiment 2. Overall, a RVF advantage resulted with horizontal items, yet no visual-field asymmetries were found with the vertical items. These results indicate that altering the orientation can affect visual-field superiority. It is proposed that the novelty of vertical displays leads to greater involvement of the right hemisphere. Imageability was related to performance only for horizontal displays; but there were no significant differences in imageability effects between the two visual fields. It is concluded that word imageability has little effect on visual-field differences, at least not for lexical decisions.