Our MS-HCI is an interdisciplinary program between the School of Interactive Computing; School of Literature, Communication and Culture; and School of Psychology. Students' core classes span all three schools, and then they specialize and conduct research in an area that falls under one or more of these schools. Several other schools, such as the School of Industrial Design and the School of Music, also have programs that relate to the MS-HCI and to HCI research in general. Various Research Centers have HCI research, faculty and facilities. At Georgia Tech, Centers tend to be larger entities than labs, and typically include multiple labs, which are included in the "Labs" drop down under research.
Considerable HCI research is conducted by individual faculty who are not associated with a lab or center. You can get a good sense of this by looking at individual faculty pages in addition to lab and center pages.
The following are the Georgia Tech centers where the majority of HCI-related research is located: