“…Two early studies (Brinker & Lewis, 1982;Dunst, Cushing, & Vance, 1985) found that infants under 12 months understood cause and effect, a necessary skill to use AT. Numerous studies in the 1980s and 1990s have shown children under age 3 could use a variety of AT, such as prosthetic hands (Cook, Liu, & Hoseit, 1990;Krebs, Lembeck, & Fishman, 1988;Meredith, Uellendahl, & Keagy, 1993); power mobility devices (Butler, Okamoto, & McKay, 1983, 1984Jones, McEwen, & Hansen, 2003;Nilsson & Nyberg, 1999;); augmentative and alternative communication (AAC) (Cumley & Swanson, 1999;Foreman & Crews, 1998); and switches to operate toys (Daniels, Sparling, Reilly, & Humphry, 1995;Ferrier, Fell, Mooraj, Delta, & Moscoe, 1996;Sullivan & Lewis, 2000). Only three studies, (McEwen, & Hansen, 2003;Sullivan & Lewis, 2000;Wilcox, Guimond, Campbell, & Moore, 2006) researched AT use with the birth to 3 population in the 2000s.…”