screen-based eye-tracker (IMAGE) Geological Society of America Caption Dr. Elijah Johnson models the screen-based eye-tracker activity used for this study, where an infrared sensor detects the visual focus of study participants. Credit: Steph Courtney. Credit Steph Courtney Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. License CC BY-NC 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.