Rock's procedure for separating the effect of objective
and retinal spatial reference by varying stimulus orientation
and body posture was used in conjunction with the "same-different"
reaction time paradigm. It was predicted that
the individual differences in perceptual processing (analytic
and structural) obtained by Hock (1973) would involve
different determinants of spatial reference, these being
retinal reference for analytic processing and objective
reference for structural processing. The results show that
analytic subjects as hypothesized, referenced perceptual
information to a retinal coordinate system. Structural
subjects however, seemed to reference perceptual information
to both objective and retinal coordinates. The results for
structural subjects were attributed to the unexpected finding
that subjects who were structural while upright, became
analytic when in a reclining position. The latter finding
suggested that Rock's methodology for separating the effects
of retinal and objective orientation relies on the subjects
employing the same mode of processing in all bodily postures.