A Mental Cutting Test Using Drawings of Intersections

摘要

In order to examine the role of information processing in recognizing 3-D objects using 2-D projection drawings, a standard paper-pencil MCT was administered to female students, who were instructed to draw intersecting lines on the surface of a test solid before choosing from a list of possible answers. As a result, it was quite possible that the ability to draw intersections itself was related to the score of the MCT, as well as to spatial ability. There were some schemes available for drawing intersections when the subjects couldn't recognize three-dimensional relations. Most of the schemes included some steps in which the subjects drew incorrect intersections using distinctive marks on the solids. Many subjects lacked a sense of depth perception, i.e., the ability to imagine three-dimensional space. At first, it was assumed that if the process of drawing intersecting lines directly on to the projected test solids were added to the MCT, it might be possible to stimulate the sense of recognizing 3-D objects even when the subjects couldn't recognize the 3-D space as a sensuous impression. However, while the low scoring MCT subjects could judge and recognize the constructional elements of the test solid distinctively to some extent, they seemed to have had much difficulty in recognizing the correct shapes of test solids or drawing intersections on the perspective drawings, because their criteria for determining three-dimensional positioning were rather vague.