Visual half-field Stroop effects with spatial separation of words and color targets

Past inconsistencies in the occurrence of differential visual half-field Stroop effects were addressed in two experiments using a visual half-field presentation technique incorporating brief displays (100 ms) and a fixation task designed to ensure proper eye fixation at display onset. Experiment 1 used displays in which distractor words and color targets were presented in contralateral visual fields. Experiment 2 compared contralateral with ipsilateral displays where words and color targets appeared one above the other in the same visual field. Stroop effects were larger whenever a word occupied the right as opposed to the left visual field, regardless of whether the color target was left or right. Results are consistent with the idea that words are processed more efficiently or automatically in right visual field/left hemisphere presentations.