Abstract
Modulations in the contrast of dynamic visual noise are invisible above a critical fusion frequency (CFF) of ~15 Hz. Nonetheless, early nonlinearities in the visual system could make low-frequency changes in the amplitude of these modulations appear as changes in intensity. In a method-of-adjustment paradigm, our observers minimized these changes in apparent intensity by manipulating the relative average physical intensities of dynamic noise with large and small amplitudes of modulation. For minimum apparent changes in intensity, observers required relatively less average (root-mean-squared) contrast and relatively more average power (mean squared contrast) when modulation amplitude was large. These results are most consistent with a power-function nonlinearity with an exponent between 1 and 2.
Meeting abstract presented at VSS 2017