Abstract
Three approaches to addressing the hypothesis of perceptual independence (Garner & Morton, 1969) were applied to the facial dimensions of identity and expression: (1) Garner's speeded classification task (Garner, 1974), (2) measures derived from systemsfactorial technology (SFT, Townsend and Nozawa, 1995), and (3) measures derived from general recognition theory (GRT, Ashby and Townsend, 1986). The overall goals of this effort were to (a) relate three theories of perceptual independence, and (b) provide a strong test of the dual-route hypothesis (Bruce & Young, 1980), for which independence is a central construct. Identity and expression appeared as integral dimensions inthe Garner test (see also, Ganel & Goshen-Gottstein, 2004). Violations of perceptual and decisional separability, but not perceptual independence, were found in the GRT tests. A parallel,self-terminating, unlimited-to super-capacity, system with dependencies in the rates of processing was revealed in the SFT tests. Taken together, these results are provocative with respect to the conceptual relations among the theoretical persepctive, and with respect to the integrity of the dual-route hypothesis.