The measurement of sensory intensity has had a long history, attracting the attention of investigators from many disciplines including physiology, psychology, physics, mathematics, philosophy, and even chemistry. While there has been a continuing doubt by some that sensation has the properties necessary for measurement, experiments designed to obtain estimates of sensory intensity have found that a general rule applies: Equal stimulus ratios produce equal sensory ratios. Theories concerning the basis for this simple psychophysical rule are discussed, with emphasis given to (...) the physical correlate theory, which considers judgments of subjective magnitudes to be based upon estimates of physical dimensions that vary regularly with changes in degree of stimulation. For the most thoroughly investigated sensory scales, brightness and loudness, the physical correlate is considered to be distance. Our “tacit knowledge” of the sensory effects of changing distance plays an essential role in matching motor activities to environmental conditions and in ensuring accurate perceptual evaluations through brightness and loudness constancies. In psychophysical experiments, subjects apparently use this same tacit knowledge when required to estimate relative subjective magnitudes. The evidence related to the physical correlate theory is summarized, and it is concluded that, while under appropriate conditions we demonstrate considerable skill in evaluating environmental relationships, we are quite unable to estimate the neurophysiological nature or quantity of sensory response. A psychophysics devoted to studying conditions required for accuracy and conditions producing errors in the perception of environmental relationships would seem to be more valuable than one devoted to subjective magnitudes. (shrink)

Probably colour is the best worked-out example of allegedly neurophysiologically innate response categories determining percepts and percepts determining concepts, and hence biology fixing the basic categories implicit in the use of language. In this paper I argue against this view and I take C. L. Hardin's Color for Philosophers [1988] as my main target. I start by undermining the view that four unique hues stand apart from all other colour shades (Section 2) and the confidence that the solar spectrum is (...) naturally divided into four categories (Section 3). For such categories to be truly universal, they have to be true for all peoples and in Section 4 I show that Berlin and Kay's [1969] widely quoted theory of basic colour categories is not sufficiently supported to lend it any credibility.Having disposed of the view that inspection of language or ‘pure’ perception unveils the universal colour categories. I turn to neurophysiological and psychophysical theories of colour vision to see whether they provide a more solid basis for deciding what the innate response categories are. In Section 5 I show that Hardin's account of the opponent-process theory neither supports his view that ‘colour-coding’takes place early in the visual neural pathway, nor his view that knowledge of colour vision science will help us solve many philosophical mysteries about colour.In Section 6 I give a more detailed review of what is known today about the neurophysiology of colour vision and I show that there's nothing in the brain which could be called a colour module, let alone a module with homunculi for particular basic colour categories. In Section 7 I show that psychophysical models do not support such rigid constraints on category formation either. Hence (Section 8), at least in the case of colour, current science supports a plasticity in the formation of categories that goes far beyond the requirements of those naturalistic philosophers who would like to ground primitive concepts in biology. (shrink)

In the course of the discussion, Professor Quine pinpoints the difficulties involved in translation, brings to light the anomalies and conflicts implicit in our ...

In this work the distinguished physical chemist and philosopher, Michael Polanyi, demonstrates that the scientist's personal participation in his knowledge, in ...

The process of recognition or isolation of one or several entities from among many possible entities is termed intellego perception. It is shown that not only are many of our everyday percepts of this type, but perception of microscopic events using the methods of quantum mechanics are also intellego in nature. Information theory seems to be a natural language in which to express perceptual activity of this type. It is argued that the biological organism quantifies its sensations using an information (...) theoretical measure. This, in turn, sets the stage for a mathematical theory of sensory perception. (shrink)

Thomas S. Kuhn's classic book is now available with a new index.

This first volume contains discussions of the brain, methods for analyzing behavior, thought, consciousness, attention, association, time, and memory.