Pictorial Depth Cues Research Articles

Responsiveness of Nigerian students to pictorial depth cues

Because research has indicated that many students in the developing countries find it hard to understand depth portrayal in Western pictures, the authors tested three groups of Nigerian high school and college students for response to four pictorial depth cues. Their tests, which used ball-and-rod models originally devised for teaching chemistry, showed no one cue to be effective with all students. The students had more difficulty with cues concerning the relative size of objects and the fore-shortening of straight lines than with cues involving overlap of lines and distortion of the angles between lines.

Development of ability to perceive and produce pictorial depth cue of overlapping.

The perception of the pictorial depth cue of overlapping was studied in children 3, 5, and 7 yr. old. Both a sequential and a simultaneous picture/object-matching task were used to test sensitivity. All age groups successfully perceived the depth relation information provided by pictorial overlapping. Height on the picture plane, which projectively covaries with overlapping, was not consistently used as a depth cue by any age group. Children's drawings were also analyzed for the presence of distance information. The drawings of the 3- and 5-yr. old children contained no overlapping cues and indicated a general lack of understanding of the third demension behind the picture plane. Seven-yr.-old children showed the beginnings of this understanding through their use of size perspective and height on the picture plane as depth cues. For all ages the production of the overlapping cue lags behind its perception.

The development of pictorial depth perception: the role of figural elevation.

This is a follow‐up of a previous study (Jahoda & McGurk, 1974), in which pictorial depth cues were systematically manipulated. In Expt. I children aged between 4 and 10 were presented with stimulus pictures in which depth cues were reduced to elevation and walking or standing posture of two figures. In one condition a training picture reminding subjects of the actual size relations remained visible, in order to test for possible memory effects, and in the other condition it was absent. As before, children were required to construct three‐dimensional models representing the size and spatial relationships between figures in the pictures, scoring being in terms of size and spatial accuracy. Results were consistent with previous ones, indicating that elevation alone constitutes a relatively weak but effective depth cue. There was a moderate memory effect, posture being insignificant. Expt. II was designed to test the hypothesis that the difficulties experienced by younger subjects are response rather than perceptually based. Children aged 4 and 6 were given the task of reproducing a three‐dimensional model. Subjects had no difficulty with size, but spatial responses were at a very low level at the age of 4, increasing significantly in accuracy by the age of 6. The predominant error at both age levels was horizontal instead of diagonal orientation. This is in conformity with the hypothesis and consistent with previous results.

Development of sensitivity to static pictorial depth information

Sensitivity to the pictorial depth cues of shading, linear perspective, and position on the picture plane were investigated with children from 3 to 7 years of age as well as with adults. Using a discriminative learning method, all Ss were found to be sensitive to shading information for depth when the display was oriented vertically, but not when it was oriented horizontally. In addition, binocular view did not decrease sensitivity relative to monocular view. Linear perspective was found to be effective in controlling 3-year-olds’ size discriminations of equal-area figures, while position on the picture plane was ineffective in the absence of other information for depth.

The control of relative size by pictorial depth cues in children and adults

A developmental study of the relation between apparent size and pictorial depth demonstrated the usefulness of operant techniques in establishing equivalent differential responding and in testing stimulus equivalence in different age groups. A visual area discrimination was established by reinforcing, on a VR schedule, responses to the larger area in each pair of figures. Presenting pairs of figures of equal area on backgrounds with pictorial depth cues produced higher response rates to the pictorially further. This size “illusion” created by pictorial cues to depth proved very effective for adults, moderately effective for 9-year-olds, ineffective for 3-year-olds.