Visual line graphs are a prevalent form of communication as they provide a pictorial means to display relationships between entities. As such, understanding the cognitive resources required in processing line graphs would inform designers how to optimize the use of graphical displays. This study systematically investigated how graph task performance changes as a function of attention allocation (full or divided) and concurrent memory task (spatial or verbal). Twenty-four younger adults (mean age 19.2 years) completed either a trend comparison task or a point estimation task and a concurrent spatial or verbal task. Trend comparison performance did not significantly differ between the full and divided attention conditions; mean performance for all conditions was over 90% accurate. Interestingly, participants' point estimation performance was significantly better for the two divided attention conditions compared to the full attention condition which may be attributed to a motivational or stimulus effect. This study provides a base from which more research can be conducted to understand the verbal and spatial resources required in graph comprehension.