ABSTRACT
Prolonged inspection of high-contrast visual displays leads to various detrimental changes in visual performance. Two highly studied effects are the impairment of contrast vision in terms of increased thresholds for detecting displays of similar spatial characteristics (Blakemore and Campbell, 1969; Pantle and Sekuler, 1968), and the perceptual distortion of supra-threshold displays of slightly different spatial characteristics (Gibson and Radner, 1937; Hofmann and Bielschowsky, 1909). In a classic monograph-length paper, Gestalt psychologists Wolfgang Köhler and Hans Wallach (1944) reported a series of experiments on perceptual distortions, termed figural aftereffects, and developed a theory in terms of electrical fields in the visual cortex to account for these adaptation effects, a theory that in principle might also account for the, then not yet discovered, contrast threshold elevation aftereffects. The pioneering studies of single cells in the visual cortex of the cat and monkey by Hubel and Wiesel (1959, 1968, 1977) buried the Gestalt theory of brain function (see also Chapter 2 by Wagemans), but spatial adaptation and aftereffects became an important research tool in the study of the functional organization of the visual system, used in countless studies in psychophysics, and human and primate electrophysiology.
