Evaluation of task performance during mentally imaging three-dimensional shapes from plane figures.

Mental imagery is an important theme in psychology. Although the mental rotation task is well known, the complicated functions in mental images with higher spatial perception remain unknown. The aim of this study was to evaluate the task performances during the mental imaging of two- or three-dimensional shapes (14 healthy male students, M age = 24.2 yr., SD = 3.4). The mental-image task to frame a 3D object from actual 2D figures (2D-3D task) had the longest reaction time (p < .01); performance accuracy on this task was lower than for other tasks. The reaction time for the 2D-3D task differed statistically significantly from that on the typical working memory task using the mental image of three 2D figures. Compared with the 2D-3D task, illustration of a simple 3D object would be effective when a quick judgment of high accuracy is required. The feasibility study using an electroencephalogram suggests that the theta-band activity at the middle frontal lobe reflecting the acts of the working memory is related with mental images.