Metaphor Mask (image) Drexel University Share Print E-Mail Caption One of the masks that was categorized as using metaphors, the most common theme in the masks that were studied. Credit Courtesy of the BMJ Open. Usage Restrictions Credit as specified. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.