(TIME) -- In the more than two decades that she has spent helping build a fledgling music-video channel into one of the most powerful global media brands, Judy McGrath, 51, has always stayed in touch with what she likes to call her "inner teen." Now that she has taken over the reins at all of parent company Viacom's vast, fast-growing cable operations, including MTV, MTV2, VH-1, CMT, Nickelodeon, TV Land and Comedy Central, you might think she would need to get more in tune with her outer adult. But being responsible for the crown jewel of Sumner Redstone's empire - generating nearly $3 billion in profits this year alone and reaching 400 million viewers in 164 countries - has done little to dull McGrath's rebellious spirit or passion for "driving creativity," as she puts it. Even with a husband and 10-year-old daughter at home, you can find this self-described "music junkie" at the occasional late-night club gig. These days, McGrath is spending lots of time overseas too, where she is intent on expanding Nickelodeon's presence and developing more original programming for MTV, including the soon-to-debut MTV Base in Africa. Back home, a year after Janet Jackson's MTV-produced Super Bowl half-time striptease, McGrath may again be a lightning rod with the February launch of her newest U.S. channel, Logo, a 24/7 network for gays and lesbians. Not surprisingly, controversy doesn't particularly concern her. Instead, says the Scranton, Pa., native, who started at MTV in 1981 as an on-air promotions copywriter, "I am always worried about missing a cultural beat." --By Daniel Eisenberg/New York

EDUCATION
Bachelor's degree in English from Cedar Crest College, 1974

CAREER
McGrath started at MTV in 1981, working as an on-air promotions writer. Ten years later, she assumed all responsibility at MTV for programming, music, production and promotion, in 1993 becoming the network's president. In 2002, McGrath also took on oversight of VHI and CMT, in her job as MTV Networks president. She became chairman and CEO of MTV Networks in 2004.