Visual Field Test of Prefrontal Cortex (IMAGE) University of California - Berkeley Caption When images are presented to the right eye of a stroke patient with a lesion in the left prefrontal cortex, visual working memory is impaired. These patients perform poorly in a test requiring that they hold a "phantom image" of a screen display in their mind for up to a second in order to match a subsequent image. The intact right prefrontal cortex picked up some of the slack, however, showing that the brain can compensate for some memory loss. Credit Bradley Voytek. Robert Knight/UC Berkeley Usage Restrictions None 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.