Remembering the Slope of a Line: Tests of a Propositional Theory of Oblique Orientation

Abstract

Two experiments are reported for which the objectives were to test facets of the Olson and Bialystok (1983) theory of spatial cognition as applied to the oblique effect. Olson and Bialystok propose that spatial information is encoded in the form of propositions that will vary in complexity depending on the number of spatial predicates required to represent that information. Experiment 1 tested this theory by varying the number of spatial predicates required to represent three oblique pairs: the standard mirror image, different direction, different slope (DD) and same direction, different slope (SD). With few exceptions, both accuracy judgments and reaction times (RTs) were consistent with predictions derived from the theory, However, the theory does not specify the order in which spatial predicates are analyzed, or whether all spatial predicates must be analyzed when making judgments about spatial information. Experiment 2 was designed to determine the steps involved in extracting spatial predicates from stunuli when making oblique comparisons. Based on the results of this experiment, a process model of the mental operations involved in making oblique comparisons was proposed.