It is therefore not true that all markings or visual elements not inherently required to communicate understandably are an unnecessary distraction, North Carolina State University and University of Idaho researchers said.
Newspapers and magazines often embellish charts or graphs to draw attention to them or to highlight information.
When a person looks at a chart or graph, two things generally happen, the researchers said.
The person initially takes in all the elements of the image at the same time, they said.
In this stage -- which is quick and generally unconscious -- any contrasting features "pop out" at the viewer, study co-author and North Carolina State psychology Professor Doug Gillan said.
The viewer then examines each component of the graph or chart separately, the researchers said.
In both cases, background images can enhance a viewer's ability to read a chart or graph, as long as the images contrast with the chart or graph itself, the researchers said.
The researchers reached their conclusions after running an experiment using rectangular bar graphs.
They tested how accurately people could read a bar graph when it was presented against a blank background, a background filled with rectangles and a background filled with circles.
People were most accurate when reading the bar graph against a background filled with circles, the researchers said. They were less accurate when the background was blank and worse still when the graph was displayed against a background of rectangles.