ABSTRACT
Three psychophysical principles common to timing and landmark-based spatial search in the pigeon are presented. First, the magnitudes (durations and distances) are measured and generated on a linear scale, where one unit of the psychological scale corresponds to one unit of the physical scale. This is inferred from the symmetrical shape of the response distributions in time and space. Second, in accord with Weber's Law, the uncertainty in the magnitude of measurement is a constant proportion of the magnitude measured. This is inferred from comparing the shapes of distributions for different target magnitudes. Third, in determining where or when the target should be, multiple sources are used. This is inferred from test conditions in which different sources point to different target criteria in space or time. This principle relates most to the theme of this book, and details of how multiple sources are used are discussed.
