After a bombing of a Visitor Mothership that was conducted by the Fifth Column, Anna came to the conclusion that these traitors were immune to her Bliss. Thus, she decided to conduct a purge of her forces in order to remove such sympathizers within her fleet. First, she met with her Chief Medical Officer Joshua where a test was devised that used Anna's reactions as a template with other Visitors being compared to it. Any that showed a higher reaction were thus feeling emotions and possible threats in order to be eliminated.
It was during the testing of Marcus's aid that it was confirmed that there was a margin of error in the Empathy Test which meant it gave a false positive in certain occasions. Rather then stop the tests, Anna had those who failed the test arrive in one of the chambers where she commanded that they take their Suicide Pills. Those that did not were thus seen as being traitors whilst those that died as a result simply gave their lives to the cause. (Pound of Flesh)The tests continued even when Anna went to meet with the United Nations in order to get Humanity to embrace Blue energy. As Joshua continued the tests, he had Lisa undergo the Empathy Test where it was revealed that she failed. Lisa at first attempted to claim that it was a mistake and even stated that her assignment with Tyler must have affected the test. However, Joshua claimed that the Visitor High Commander's directive was clear - to terminate any that failed the test. Whilst this was the case, Joshua was in fact a member of the Fifth Column and he decided to forge the results of the Empathy Test in order to make it appear that Lisa passed. When Lisa asked him why he told her mother that she passed, Joshua said it was because he would ask her for a favor in the future and she would need to comply with it. (We Can't Win)