2 conditions, condition 1 = 2 visual tasks, condition 2 = 1 visual, 1 verbal. Ppts found it harder in condition 1 as the 2 tasks were competing for the same limited resources of the visuospatial sketchpad. Condition 2 was easier as ppts used separate resources of the visuospatial sketchpad and phonological loop. This supports the idea of separate components in the working memory otherwise performance would've been the same on both tasks.