Bias in the priming of object decisions: logic, assumption, and data

R. Ratcliff and G. McKoon (1995) describe 7 experiments that led them to conclude that priming of possible but not impossible objects on the object decision task introduced by D.L. Schacter, L.A. Cooper, & S.M. Delaney (1990) is attributable to explicit memory processes that offset a bias to call studied objects "possible." On the basis of this point, Ratcliff and McKoon (1995) claim to have undermined our hypothesis that a structural description system plays an important role in object decision priming. Ratcliff and McKoon (1995) also offer a general critique of multiple memory systems accounts of priming and explicit memory. Ratcliff and McKoon's (1995) arguments are based on an inaccurate characterization of Schacter et al.'s theoretical position; the evidence for Ratcliff and McKoon's (1995) idea that explicit memory offsets bias is weak, and the central assumptions that underlie both Ratcliff and McKoon's (1995) specific experimental manipulations and their general conclusions are questionable.