 Following Data 's defeat at a game of <unk> in " Peak Performance " , Pulaski and Councillor <unk> <unk> ( Marina <unk> ) attempt to console him , but it is left to Captain Picard to convince Data that he is not malfunctioning . Pulaski 's final appearance on The Next Generation was in the episode " Shades of Gray " . When Commander Riker falls ill to a dangerous virus during an away team mission , Pulaski drives out the virus with a device that stimulates his memory centre . After she discovers that negative memories are more effective in removing the virus , she uses memories of fear and survival to save Riker 's life . 
