The effect of photometric brightness on judgments of distance

Thesis (Ph.D.)--Boston University.It is generally accepted that the brightness of a stimulus object is a factor in judgments of distance. However, very little knowledge about the functional relationships between photometric brightness and distance judgments have been obtained. Graham and others have shown that the psychophysical methods used to obtain stimulus-response relationships can also provide stimulus-stimulus functions. In the latter type of function information can be obtained which shows how one measurable stimulus attribute varies as a function of another, with the response as a parameter. This study was concerned with determining both of these relationships. The specific objectives in this study were: (1) to discover the functional relationships between ratios of photometric brightness and judgments of distance under binocular and monocular conditions (the major experiment) and (2) to show the effect of brightness ratios on judgments of distance when the absolute level of brightness is varied (the minor experiment). [TRUNCATED