Abstract: This experiment investigated the estimation of area constructed by imagery in comparison with the estimation of area perceived.The stimuli consisted either of a rectangle or of a group of its necessary component parts,e.g.the line(s)and corner(s),were presented visually or tactually.Ss were then asked to estimate the area of a rectangle perceived or constructed from the parts by imagery and to assign a number to it in accordance with a standard one which became familiar at the beginning of the experiment.It was found that the increase of area constructed by imagery obeyed the power function law as the increase of area perceived,the index was 0.601-0.830(visual experiment)and 0.524-0.787(tactual experiment).The results confirmed the functional equivalance of imagery and perception.

Key words: estimation of area, imaginal construction, perception, functional equivalance