Talk 6

Replication and Critique of McCourt & Foxe's "Brightening Prospects for Early Cortical Coding of Perceived Luminance"

Can Ozger

McCourt & Foxe (2004) investigated the color perception illusion known as the White's Effect and proposed an early component of an Event Related Potential (ERP), known as C1, as evidence for low-level or early theory of brightness perception. We successfully replicated the experimental design of McCourt & Foxe and obtained similar ERPs. We argue that the amplitude difference in the C1 waveform is caused by a shift in the grating used to induce the illusion between experimental conditions. This shift causes a change in the stimuli and elicits a change in C1 amplitude, instead of being caused by the illusion as the authors suggest. Additionally, we propose that the later ERP component, P3, may be another cause or contributor to the White's effect.