Components of reflexive visual orienting to moving objects

Posner and Cohen (1984) and Maylor (1985) initially observed that a luminan ce change produces both facilitatory and inhibitory effects on subsequent d etection. While Posner and Cohen claimed that the facilitatory effect was m apped in retinotopic coordinates, they showed that inhibition of return (IO R) was mapped in "environmental coordinates." Tipper and colleagues flipper , Driver, & Weaver, 1991; Tipper et al., 1991; Tipper, Weaver, Jerreat, & B urak, 1994) and Abrams and Dobkin (1994b) have recently reported that IOR c an be object based, but contradictory results have also been reported Mulle r & von Muhlenen, 1996). Here we report six experiments showing that an uni nformative peripheral cue, can generate either facilitatory or inhibitory o bject-based effects that can tag moving objects and that can persist for se veral hundred seconds. Although the boundary conditions determining which e ffect will be manifest remain to be defined, the present results suggest th at facilitation and inhibition are generated independently, rather than bei ng components of the same biphasic process.