Multifocal methods refer to the possibility of presenting many stimuli concurrently and assessing the response to each stimulus and also nonlinear interactions between the stimuli in time and space. Visual evoked potentials (VEPs) refer to recording the responses of the visual brain through the placement of up to 128 or more electrodes on the scalp. These methods can be used to study diseases affecting vision and cognition or basic visual processing. One of our developments has been the use of spatially and temporally sparse multifocal stimuli to increase the signal quality, and reducing the required recording duration. Any type of visual stimulus can be used and interactions between visual and other stimulus types, for example auditory stimuli, are also possible.