^BBSnline

Color, Consciousness, and the Isomorphism Constraint

Palmer, Stephen E. (1999) Color, Consciousness, and the Isomorphism Constraint.

Short Abstract:

The relations among consciousness, brain, behavior, and scientific explanation are explored within the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument -- reversing the experience of a rainbow -- would not work. Three other color-to-color transformations might, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the isomorphism constraint, between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness, but objective knowledge of another person's experience appears impossible. The implications of these arguments for functionalism are discussed. In this article I discuss the relations among mind, brain, behavior, and science in the particular domain of color perception. My reasons for approaching these difficult issues from the perspective of color experience are two-fold. First, there is long philosophical tradition of debating the nature of internal experiences of color, dating from John Locke's (1690) discussion of the so-called "inverted spectrum argument". This intuitively compelling argument constitutes an important historical backdrop for much of the article. Second, color is perhaps the most tractable, best understood aspect of mental life from a scientific standpoint. It demonstrates better than any other topic how a mental phenomenon can be more fully understood by integrating knowledge from many different disciplines (Kay & McDaniel, 1978; Thompson, 1995; Palmer, in press). In this article I turn once more to color for new insights into how conscious experience can be studied and understood scientifically. I begin with a brief description of the inverted spectrum problem as posed in classical philosophical terms. I then discuss how empirical constraints on the answer can be brought to bear in terms of the structure of human color experience as it is currently understood scientifically. This discussion ultimately leads to a principled distinction, called the isomorphism constraint, between what can and what cannot be determined about the nature of experience by objective behavioral means. Finally, I consider the prospects for achieving a biologically based explanation of color experience, ending with some speculations about limitations on what science can achieve with respect to understanding color experience and other forms of consciousness.

Long Abstract:

The relations among consciousness, brain, behavior, and scientific explanation are explored within the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke's "inverted spectrum argument" about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument -- reversing the experience of a rainbow -- would not work. Three other color-to-color transformations might, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the isomorphism constraint, between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness, but objective knowledge of another person's experience appears impossible. The implications of these arguments for functionalism are discussed. In this article I discuss the relations among mind, brain, behavior, and science in the particular domain of color perception. My reasons for approaching these difficult issues from the perspective of color experience are two-fold. First, there is long philosophical tradition of debating the nature of internal experiences of color, dating from John Locke's (1690) discussion of the so-called "inverted spectrum argument". This intuitively compelling argument constitutes an important historical backdrop for much of the article. Second, color is perhaps the most tractable, best understood aspect of mental life from a scientific standpoint. It demonstrates better than any other topic how a mental phenomenon can be more fully understood by integrating knowledge from many different disciplines (Kay & McDaniel, 1978; Thompson, 1995; Palmer, in press). In this article I turn once more to color for new insights into how conscious experience can be studied and understood scientifically. I begin with a brief description of the inverted spectrum problem as posed in classical philosophical terms. I then discuss how empirical constraints on the answer can be brought to bear in terms of the structure of human color experience as it is currently understood scientifically. This discussion ultimately leads to a principled distinction, called the isomorphism constraint, between what can and what cannot be determined about the nature of experience by objective behavioral means. Finally, I consider the prospects for achieving a biologically based explanation of color experience, ending with some speculations about limitations on what science can achieve with respect to understanding color experience and other forms of consciousness.

Keywords:	Isomorphism constraint, color perception, inverted spectrum
Subjects:	Psychology: Behavioral Analysis Psychology: Cognitive Psychology Psychology: Perceptual Cognitive Psychology
ID code:	bbs00000504
Deposited by:	Steve Palmer on 02 May 2001