Glenn Shelton conducted an experiment in his three freshman English classes to test the effects of brain breaks on comprehension. He gave a long PowerPoint presentation with a quiz at the end to his first block without a break, one break to the second block, and two breaks to the fourth block. The average scores on the quiz were 65 for the first block, 78 for the second block, and 85 for the fourth block, supporting the theory that brain breaks can increase comprehension.