Volume 1
A text-book of experimental psychology : with laboratory exercises / by Charles S. Myers.
- Charles Samuel Myers
- Date:
- 1911
Licence: Public Domain Mark
Credit: A text-book of experimental psychology : with laboratory exercises / by Charles S. Myers. Source: Wellcome Collection.
92/370 page 72
![less difficulty, more highly saturated sensations than any other external source of stimuli. When highly saturated colour sensations, e.g. those yielded by the spectrum, are compared, they obviously differ among one another in brightness. Under ordinary conditions of vision, yellow is the region of maximal ‘ brightness value.’ Brightness is a psychical character which is distinct from intensity and saturation. Unlike these, it has no obvious physical correlate (exp. 47). We shall soon be in a position to realise that these four characters of colour sensation, hue, intensity, saturation, and brightness, are determined not merely by the nature of the stimulus, but also by the condition of the cerebro-retinal apparatus at the time of stimulation. [Our colour sensations in everyday life are greatly influenced by previous knowledge. We come to ascribe an absolute colour to all familiar objects, and we either wholly neglect occasional variations in their colour, or else treat them as chance modifications of an underlying absolute colour. We unconsciously make allowance for, and hence fail to observe, such differences in shade as experience has taught us to expect under different conditions of illumination (exp. 48). When, on the other hand, we are forced to notice the altered colour of a well-known object,—when, for example, we behold the rosy glow shed by the setting sun on a snow mountain,—we cannot resist the interpretation that we are looking at a really white surface accidentally reddened by the peculiar illumination under which it is viewed ; for this reason we tend to underestimate the degree of redness of the snow. Nor are such innate tendencies dispelled by the fullest conviction that the hue is determined both by the nature of the object and by the nature of the illumination under which the object is viewed.] The Conditions of Colourless Sensations.—A colourless sensation may be produced by re-combining all the spectral colours obtained by the analysis of white light. It may also be produced by combining merely three colours in appropriate proportions, provided that they are properly](https://iiif.wellcomecollection.org/image/b3135984x_0001_0092.jp2/full/800%2C/0/default.jpg)
