EXCLUSIVE: Twilight‘s Kristen Stewart has joined the ensemble cast of writer-director Tim Blake Nelson‘s Anesthesia in a small role. She’ll be shooting for a few days on the indie, about a group of New Yorkers whose lives are touched by the same philosophy professor. Pic is currently filming in NYC. Nelson’s last directorial effort was 2009’s Leaves Of Grass, which he also starred in and scripted. Stewart is repped by The Gersh Agency.