Rebecca K. Jones

On a neglected variable in theories of pictorial perception: Truncation of the visual field

Theoretical analyses of pictorial perception have concentrated on the consequences of conflicting flatness and depth information in pictures, but have failed to consider the perceptual effects of the truncation of the visual field attendant on any pictorial display. The importance of this variable both for methods of testing pictorial information and for theory building was demonstrated. Under four different viewing conditions, adults were asked to scale the size and distance of five isoceles triangles at five different distances. The four conditions were unobstructed static monocular view, peephole view, view through a rectangular frame, and view of all the stimuli photographed in a slide. The slopes of the peephole, truncation, and slide conditions’ scaling functions were all significantly smaller than the slope of the untruncated Monocular condition, and the Y-intercepts were all greater. A decrease in over-constancy in the size functions indicated a similar effect for all three truncated conditions. Results are interpreted as supporting the hypothesis that truncation of the visual field, both in pictures and in peephole views of the real world, causes a frontal shift in the localization of the visible field, with a resultant compression of perceived size and distance.

James Gibson's Ecological Revolution in Psychology

Revolutions in politics involve changes in the traditional order of a society, and it is an open problem as to how to describe such changes. Is the British upheaval of 1688-89 a revolution? Is the U.S.A.’s Civil War a revolution? Precisely when did the French revolution occur? This list of questions could be extended. But what about revolutions in science, are there changes in the traditional order of a science? If so, can we say more about what that might mean? Currently in philosophy of science, the concept of a scientific revolution has attained great prominence. Unfortunately, the understanding of such revolutions seems to be inversely proportional to the popularity of the concept. The most telling problem in the theory of scientific revolutions is that all the ostensible students of revolutions in fact have studied non-revolutionary science. Kuhn, forexample, is most famous for his concept of ‘paradigm’, which explains normal science so-called, not the structure of scientific revolutions. Similarly, Lakatos speaks of research programmes, thereby denying the existence of ’real saltations’ in the evolution of the sciences. To continue ourgeological metaphor,

Towards a definition of living systems: A theory of ecological support for behavior

It is proposed that the Darwinian theoretical approach and account of living systems has not yet been clearly given. A first approximation to this is attempted, focussing on behavior in evolving environments. A theoretical terminology is defined emphasizing the mutuality of organism and environment and the existence of biologically theoretical entities.

A Perspective on Cross-Cultural Picture Perception

Publisher Summary This chapter reviews the literature dealing with cross-cultural research in picture perception. The question of how useful pictorial information is for instructing newly literate or illiterate people is difficult to answer. In Western cultures, pictures are used ubiquitously as tools for teaching and communication. The tacit assumption behind this use is that pictures are at least as good or better than written messages. Cross-cultural research can help answer the question whether pictures serve non-Western cultures as well as Western cultures. Research into the perception of pictures by people from non-Western cultures has used a variety of stimuli: line drawings, black and white photographs, and color photographs. The perception of depth is an arduous task made increasingly difficult by the tests used to investigate pictorial depth perception. In addition to the hypothesis that pictorial experience determines pictorial capabilities, it has been suggested that people in varying cultures perceive the world differently.

Differential Patterns of Preference for Modified Linear Perspective in Children and Adults.

Abstract Two experiments were designed to investigate the development of a preference for minimal convergence in pictures. Pictures varying in degree of convergence from conic to parallel were observed three at a time under two conditions: monocularly at the correct station point for the conic projection, and freely with unconstrained view. Subjects were children in nursery school (age: 4 years) and first grade (age: 6 years), and adults in college. Subjects were asked to choose the “best” picture. In the correct station point condition the younger children preferred the most conic picture, while adults chose the most parallel projection significantly more frequently than either remaining choice. First-grade children were in transition between these two modes of responding. In the free view condition, the younger children showed no strong preferences, while older children and adults preferred parallel projections significantly more frequently than more convergent pictures. Results were interpreted in context of the development of the “Zoom effect,” an assumption of appropriate viewing distance 10 times as great as the size of the pictured object.

A distinctive characteristic of pictorial perception: the zoom effect.

To investigate the role of flat surface information for the plane of projection in pictorial perception, three studies were designed in which varying amounts of such information were made available to adult subjects. The first study tested preferences for true or modified linear perspective under conditions of presence or absence of surface texture cues for the plane of projection. In the second and third studies, the absence of texture cues for the plane was coupled with the addition of motion parallax and binocular information respectively. It was found that adults showed a consistent preference for parallel perspective in pictures when the flat-surface information was provided either by visible texture or by motion parallax; but no consistent preference for either true or modified perspective in the absence of all three sources of flatness information or when the flat surface information was given only by binocular cues in the absence of visible surface texture or head motion.

THE PERCEPTUAL CONSTRAINTS ON CHOOSING A PICTORIAL STATION POINT

The constraints on an artist in the choice of a pictorial station point are discussed in the contexts of art history and present-day perceptual psychology. The concepts of Alberti, Dürer and Leonardo da Vinci are compared with the current speculations of Gibson and Pirenne. Experimental evidence is reported that reveals that representational pictures possessing linear perspective whose center of projection is at a distance of about 10 times the size of the object pictured are the most acceptable for Western adults regardless of the locations they chose for viewing them. Further experiments with young children show that this preference develops in the early school years, perhaps as a result of increased experience with pictorial materials. The prescriptions of Leonardo da Vinci and Albert Einstein are most clearly supported by these findings.