Purchase this article with an account.
Anthony D. D'Antona, Steven K. Shevell; Distortion products in chromatic induction: Nulling of induced temporal frequencies not present in the stimulus. Journal of Vision 2006;6(6):238. doi: https://doi.org/10.1167/6.6.238.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
PURPOSE: Chromatic induction is the color change of an object caused by its chromatic surround. The magnitude of time-varying chromatic induction from a time-varying surround is strongly attenuated above ∼3 Hz. Surround temporal frequencies >3 Hz, however, can cause time-varying induction when two frequencies are presented in the surround simultaneously. The induced temporal variation is at the difference frequency of the two frequency components in the surround. Here, we show a neural response is present at the difference frequency by canceling it with added out-of-phase light. METHODS: A steady equal energy white (EEW) annular test was embedded within a larger circular surround. The surround was temporally modulated along either the l or s chromatic direction of MacLeod-Boynton color space. Pairs of temporal frequencies were presented in the surround simultaneously. The observer adjusted the amplitude, DC level, and phase (0 or 180 deg) of a sine-wave stimulus added to the test annulus; the frequency was the difference of the two temporal frequencies in the surround. The observer's task was to make the test annulus appear steady and achromatic. RESULTS & CONCLUSIONS: For both chromatic axes, observers nulled the induced temporal variation with a consistent non-zero nulling amplitude, confirming that chromatic induction from high temporal frequency surrounds depends on a distortion product of a nonlinear neural process. The nonlinearity causes high frequency surrounds, previously thought to be ineffective for induction, to induce low frequency variation, which may be useful for segmenting an object from its temporally varying background.
This PDF is available to Subscribers Only