fMRI BOLD SIGNAL CHANGES AS A POWER FUNCTION OF LUMINANCE: AN INTERNAL PSYCHOPHYSICS APPROACH
An event-related functional MRI, using the blood oxygen level-dependent (BOLD) method, has become the preferred procedure for imaging the course of oxygeneration and by inference brain's neuronal activity accompanying subjective sensory experience. We measured how the BOLD imaging signal changes when perceived brightness changes as a power function of luminance. We found the BOLD signal tended to change as a power function of luminance intensity. We thus propose a new neuronal model of the internal psychophysics based on BOLD imaging signal (A BOLD psychophysics).