Induction effects for heterochromatic brightness matching, heterochromatic flicker photometry, and minimally distinct border: implications for the neural mechanisms underlying induction

Abstract

Brightness induction refers to the finding that the apparent brightness of a stimulus changes when surrounded by a black versus a white stimulus. In the current study, we investigated the effects of black/white surrounding stimuli on settings made between red and green stimuli on three different tasks: heterochromatic brightness matching (HBM), heterochromatic flicker photometry (HFP), and minimally distinct border (MDB). For HBM, subjects varied the relative luminance between the red and green stimuli so that the brightness of the two colors appeared equal. For the two other tasks, matches were made based on minimizing red/green flicker (HFP) or the saliency of a red/green border (MDB). For all three tasks, the presence of black/white surrounding stimuli significantly altered red/green settings, demonstrating the existence of induction effects. These results are discussed in terms of which underlying color pathways (L+ M versus L-M) may contribute to induction effects for the different tasks.

Individual Variability in Simultaneous Contrast for Color and Brightness: Small Sample Factor Analyses Reveal Separate Induction Processes for Short and Long Flashes

“…These studies suggest the fast-responding mechanisms are underlying simultaneous contrast. In contrast to these recent discoveries, others have demonstrated that brightness induction was only seen with a slow-modulating stimulus, which suggests that sluggish mechanisms are underlying simultaneous contrast ( De Valois, Webster, De Valois, & Lingelbach, 1986 ; Gunther & Dobkins, 2005 ; Rossi & Paradiso, 1996 ).…”

“…We speculate that this difference may suggest slightly different temporal tunings of fast and slow mechanisms for decrements and increments, though this outcome could also reflect random effects caused by small sample size. In fact, Gunther and Dobkins (2005) examined the brightness induction effect with flickering stimuli and reported that the brightness induction effect was strong at low (4 Hz) and high (>20 Hz) temporal frequencies while the effect is weak at mid-range temporal frequencies, in other words, double crossover (see Gunther & Dobkins, 2005 ; Figure 2 ). In addition, it has been suggested that the processing of luminance increment and decrement is separate and temporally different (e.g., Wehrhahn & Rapf, 1992 ).…”

The Use of Chromatic Information for Motion Segmentation: Differences between Psychophysical and Eye-Movement Measures

“…2.4 Setting red/green equiluminance Fourteen adult subjects provided red/green equiluminance points obtained by heterochromatic flicker photometry (eg Gunther and Dobkins 2005;Kremers et al 2000;Smith and Pokorny 1975), to be used in setting the red/green in the main experiment. Subjects were presented with the same display of 603 dots as in the main experiment, except that, rather than moving, the dots alternated between red and green at a rate of 30 Hz.…”