The League of Women Voters of Lexington will host a forum exploring the effects of violence portrayed in the media Thursday at 7:30 p.m. in the Lexington High School auditorium. The discussion, featuring authorities on the media and child development, will kick off a yearlong examination aimed at raising awareness about violent media, including its positive and negative effects on social behavior and the development of children, in the league’s third annual Community Conversation. The panelists at this week’s session will be Dr. Michael Rich, the director and founder of the Center on Media and Child Health at Boston Children’s Hospital; Lesley University professor and child development expert Nancy Carlsson-Paige; and Tom Fiedler, dean of Boston University’s College of Communication. Anthony Brooks, cohost of “Radio Boston” on WBUR, will moderate the program. For more information, contact Paula Antonevich at email@example.com or 781-674-2795.