Contrast dependence of contextual effects in primate visual cortex.

Investigates the relative activity levels of neurons at different points across the cortex by varying the relative contrast of stimuli over the receptive visual field and surrounding regions. The changes caused by altering the balance of the excitation driving center and surround regions; The impact on the sign and stimulus selectivity of these contextual effects; The suggestion of a complex gain-control mechanism that regulates cortical neuron responsiveness.