Effects of typeface characteristics on visual field asymmetries for letter identification in children and adults

The current study compared the effects of three typeface characteristics (script-likeness, or resemblance to cursive writing; confusability, or likelihood of confusing one letter with another; and difficulty, as indexed by naming latency) on letter identification in a divided visual fields test. It also asked whether and how these effects change with subject age. Subjects were 48 right-handed 9- and 14-year-old boys and undergraduate men--16 in each age group. They orally identified single letters in eight different typefaces presented tachistoscopically to the left or right visual hemifield. The difference between hemifields in threshold presentation time was the dependent measure. For all ages, the direction and degree of the visual field advantage changed with typeface complexity (a composite index of the three characteristics), with the simplest typeface yielding a right visual field/left hemisphere advantage, and with two of the most complex typefaces yielding a left visual field/right hemisphere advantage. There were age differences, though, in the relative contribution of the individual characteristics to this effect. For undergraduates, the strongest predictor of right hemisphere participation was script-likeness, whereas for 9- and 14-year-olds it was typeface difficulty.