Evaluation of Mentally Perceived Differences Between the 3D Objects Used in Mental Cutting Tests

E. Tsutsumi ; A. Ichikawa ; N. Kadowaki

Journal for geometry and graphics, Tome 5 (2001) no. 1, pp. 101-11.

Résumé

We examined the issue of recognizing 3D objects through the measurement of the mentally perceived differences between the 25 solid objects used in the MCT. Subjects were required to arrange actual solid models along a straight line based on their perception of similarities between the solid models. The distances between adjacent solids were transfered into a distance matrix which was analyzed using multidimensional scaling methods. The similarities between the solids were interpreted in a chart of constellation that was constructed using axes of dimension 1 and dimension 2, which were extracted by multidimensional scaling. The results show that subjects seem to pay intense attention to the following details of the solid objects: (1) impression of the solid shape as a whole which is then compared to some geometrically distinctive fundamental forms, and (2) characteristic local shapes which symbolize the solid. In judging mentally perceived differences between solids, high scoring subjects in the paper-pencil MCT were not influenced by the similarity of characteristic local shapes and they were able to classify the objects clearly considering the structural differences. Meanwhile, low scoring subjects in the paper-pencil MCT were influenced by the similarity of characteristic local shapes and had a tendency not to clearly separate the results of classification.