Showing papers by "James J. Gibson published in 1969"

The change from visible to invisible

Abstract: It is argued that the problem of the phenomenal persistence of objects in experience, often called “object permanence,” is actually a problem of the discriminating of persisting from nonpersisting things. A distinction is made between objects that go out of sight and objects that go out of existence, and it is shown that optical information exists to distinguish these two cases. Evidence is provided from a series of motion picture displays to suggest that Os do in fact distinguish them. The various optical transitions are shown to be reversing in the first case, but nonreversing in the second. In particular, the transition that specifies the occlusion of one surface by another is analyzed, together with the inverse of this transition. This study is a sequel to an earlier one of optical transformations.

The change from visible to invisible: A study of optical transitlons'

Abstract: motions that make them perceptible toan O. Several kinds and variables of optical motions weredescribed, all of which were loosely termed "opticaltransformations," and these were illustrated in a motionpicture film (Gibson, 1955).We have recently been concerned, however, with anotherclass of events, the perception of which needs to beunderstood. When an object

Are there sensory qualities of objects

Abstract: As a scientist who believes that philosophical debate is a good thing for theory-making, I am grateful to J. W. Yolton for his appreciative criticism. I will confine my reply to one of his points only, his assertion that my theory of perception underplays the role of the \"sensory qualities of objects\" in the pickup of information. Yolton says that the information acquired in perception is \"frequently (perhaps in an extended sense always) sensory\". What does he mean by \"sensory\"? If he means that all such information depends on sensitivity, I agree, but if he means that it depends on the having of subjective sensory impressions, I do not. The difficulty arises with such qualities of an object as hot, red, hard, and large. These, he says, are sensory qualities. But I argue that these only differ from other qualities of objects (edible-inedible, ripe-unripe, smooth-textured, friend or enemy) in this respect: that the subjective sense-impressions are more noticeable, more available to introspection, more obtrusive. I want to suggest that there are no special qualities of objects that have to be designated as sensory. In the course of detecting the temperature of a surface by the hand it may be almost inescapable that we should have a sensation like hot. When we perceive the differential reflectances of things it is easy to have the sensation of red. When testing for the composition of an object the feeling of hard, the unyielding resistance to my grasp, may be noticeable. And in observing the size of an object one may well be impressed by how large it looms in the field of view. But these impressions do not require us to believe that the temperature, reflectance, composition, and size of an object are qualities with a special status. To be explicit, I argue that there are no such entities as the sensory qualities of objects; if there are none they can have no role to play in the pickup of information about the environment. It seems to me that a quality of an object belongs to the object and that the quality of a sensation does not. I take the word 'sensation' to mean a subjective experience. Such