Orientation and form

by Irvin Rock

For researchers in perception, cognitive and physiological psychologists, visual research workers, and others.

Chapter I. The problem --
Chapter II. Retinal orientation versus assignment of directions --
Experimental evidence --
Symmetry --
The assignment of directions --
Conclusions --
Chapter III. The assignment of direction factor --
The effect of degree of orientation change on shape --
the perception of tactually disoriented figures --
why does recognition occur at all when directions are incorrectly assigned? --
Chapter IV. The retinal factor --
The basis of perceptual change with change of retinal orientation --
The conditions under which a retinal effect occurs --
Is the retinal factor based on change of retinal orientation? --
Recognition as a function of degree of retinal disorientation --
Chapter V. Discussion --
Theories about orientation of form --
Anisotropy and form perception --
Retinal change and change of assigned directions combined --
The "purpose" of change of appearance in form with change of orientation --
The issue of adaptation to a disoriented retinal image --
Form orientation in children --
Chapter VI. Implications for a theory of form perception --
Implications for the process of recognition --
Chapter VII. Summary and conclusions.

165 pages, Hardcover

First published April 10, 1974

About the author

Irvin Rock (1922–1995) was an American experimential psychologist who studied visual perception at the University of California at Berkeley.

His The Logic of Perception led to him being regarded as an excellent perception psychologist. Rock is notable in the field of psychology for his 1957 experiment where he tilted a square to make it look like a diamond and then tilted his test subjects and asked them what shape they saw. The experiment tested Rock's hypothesis that perceptual phenomena could be explained by higher-level mental processes instead of merely by automatic processes. When his test subjects continued to perceive the shape as a diamond after being tilted to view the shape as a square, Rock concluded that perception is an intelligent, higher-level mental process. This differed from previous conclusions by Gestalt psychologists that perception was not a higher-level process. Rock later wrote another important book on the field of inattentional blindness.