Direct Brain Stimulation Maze (IMAGE) University of Washington Caption The absence or presence of phosphenes -- visual artifacts that can be created through direct brain stimulation -- told the test subjects whether to move forward or down in the maze. Credit University of Washington Usage Restrictions With credit 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.