INVARIANCE OF PERCEPTUAL SPACES AND PERCEPTUAL SEPARABILITY OF STIMULUS DIMENSIONS

This article reports an extension of a paradigm for studying processin g of perceptual dimensions. The paradigm is the complete identificatio n task with a feature-complete factorial design (FCFD) of stimuli prov iding data for multidimensional signal detection analyses. The extensi on uses blocks of trials with subsets of the FCFD stimulus set, allowi ng estimation of various d's for inferring perceptual separability (PS ) of dimensions and for disambiguating stimulus configurations when PS fails. Results of 4 experiments found the following: PS of are curvat ure and line orientation in a discrimination task (Experiment 1), incr easing PS failure in detection of horizontal and vertical lines (Exper iment 2a), 45 degrees and 135 degrees (Experiment 2b), and 50 degrees and 60 degrees oblique lines (Experiment 2c). in each experiment, corr esponding d's remained equivalent across blocks with different stimulu s subsets.