Metaphor Mask (IMAGE) Drexel University 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 <i>BMJ Open</i>. Usage Restrictions Credit as specified. License Licensed content 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.