Hemifield dependence of responses to colour in human fusiform gyrus.

To investigate the hemifield dependence of visually evoked responses to colour in the human fusiform gyrus we recorded evoked potentials from subdural electrodes in a patient suffering from occipital epilepsy. The responses in the fusiform gyrus show a strong hemifield dependence and discriminate the onset from the offset of the stimulus. Additionally, we found responses to squares made of random dots, whereas no responses were found to squares with a homogeneous bright surface. Our findings further support the idea that the fusiform gyrus is related to colour and pattern perception. However, the hemifield dependence we found may indicate that further processing is required in order to combine information from both visual hemifields.