AN EXPERIMENTAL STUDY ON THE MEASUREMENT OF THE THRESHOLD OF CLOSURE PHENOMENON
1962 Volume 33 Issue 3 Pages 125-132
Details
1962 Volume 33 Issue 3 Pages 125-132
The concept of closure means a tendency on the part of an organism perceptually to complete stimulus presentations which are physically incomplete. But, when any one outline figure is very incomplete the tendency to perceive each part separately is stronger than to see the parts in a unitary manner. The general purpose of the present study is to determine whether or not, in the case of a diamond outline figure, the tendency toward closure could be psychophysically measured. It is possible, in the case of a diamond, to measure the threshold of closure as the percentage of the perimeter of the figure presented compared with that of a complete one. The threshold of closure was defined by Bobbitt (1) as that point in the series which represents the transition between forms having the quality of twoness and those having the quality of oneness. In the present study, the threshold of closure was measured for six different kinds of diamond having small or large apex angle. The apex angles (vertical angles) were respectively 40°, 50°, 60°, 70°, 80° and 90°. The exposure time interval of stimulus figures was a tenth of a second.
The main results were as follows:
1) Since the threshold of closure, in the case of diamond figures, is a very stable one, it is possible psychophysically to measure the phenomenon of closure.
2) For the diamonds used here, the size of threshold varied directly with the size of the apex angle, i.e., the figure with the smallest apex angle had the lowest threshold, the figure with the largest apex angle had the highest one.
3) However, the data of this study indicate that the important determinants of the location of the threshold include not only the angular characteristics of the figure, but the degree of proximity between the angles of the two jointed lines representing the opposite side of the diamond, and that the larger the angle of the opposite sidelines are, the more effective the factor of proximity is.
4) It must be emphasized that the angular characteristics which are important are those of the really perceived lines, not of the imaginary ones.
