THE CRAIK-OBRIEN-CORNSWEET EFFECT AND BRIGHTNESS INDUCTION BOTH PROCEED BY THE SPREADING OF BRIGHTNESS INFORMATION

Background: The Craik-O'Brien-Cornsweet effect (COCE) is a visual illu sion where the luminance of image boundaries sets the apparent brightn ess of enclosed regions. The COCE may be produced by the cortex constr ucting the observed brightness through a lateral 'filling-in' process: propagating brightness information from the edges of the enclosed reg ions towards their centres, Any such filing-in process would imply a s peed of propagation. Methods: Data on the propagation speed of brightn ess information in two different brightness induction effects are comp ared using a multivariate regression analysis. Results/Conclusion: We demonstrate similar non-zero speeds for the COCE and for a brightness contrast effect.