G T Shippey | PubMed Health

PubMed1998

Orientation in physical reasoning: determining the edge that would be formed by two surfaces.

Physical reasoning is strongly influenced by various parameters of orientation. The authors report 3 experiments in which this phenomenon was explored for a particularly elementary transformation: the formation of a line from the intersection of 2 planes. Participants perceived pairs of planar surfaces (disks) in a variety of orientations in 3-D space and indicated the orientations of the edges that would result if the surfaces interpenetrated. The ranges of error and response time were large. Performance depended on whether the orientation of the edge that would be formed was the same as components of the orientations of the perceived surfaces, the degree to which the orientation of the edge would be canonical in the environment, and whether the angle between the surfaces would be perpendicular. The results are discussed in the context of a general approach to orientation in perception and physical reasoning.

Adult↗

PubMed1996

Imagining projective transformations: aligned orientations in spatial organization.

Four experiments were conducted to investigate whether variations in orientation that profoundly affect the ability to imagine rotations also affect the ability to imagine projective transformations. For a basic rectilinear object and the three simpler Platonic Solids, imagining projective transformations (e.g., the casting of a shadow) was quite successful when the objects were aligned with the direction of projection. For the solids, this alignment occurred when the objects were generalized cylinders about axes aligned with the projection. As the objects were made more oblique to the projection, performance deteriorated markedly. When the objects were moderately aligned with the projection, performance depended on the orientation of the object and the orientation of the projection to the environment. We suggest that the imagination of projection and of rotation is a type of problem solving in which spatial structures are organized in relation to initially given properties of the objects and transformations. When there is alignment among the various structural components, this process of imagination works efficiently. Without such alignment, nonexperts often fail. We suggest that aligned (i.e., parallel and perpendicular) orientations are effective in spatial imagination because they are categorically distinct and singular, and they provide a critical form of redundancy.

Adult↗