Figure 2.

Neurons with shifting receptive fields (RFs) in frontal and parietal cortex. (a) The defining characteristic of a neuron showing a shifting RF is that just before the onset of a saccade, a region of the visual field becomes sensitive to visual stimulation. This region has the same spatial relation to the target of the saccade as the RF has to the present fixation point. The region is referred to as the future field (FF) of the neuron. (b) An example of an FEF neuron with a shifting RF. The left column shows the response in a spike density plot over multiple trials to a 50 ms probe stimulus in the RF of the neuron (upper record) and the lack of response at that time in the FF (lower record). The right column shows the increase in activity to the probe stimulus in the FF flashed just before the onset of the saccade and the lack of response in the RF field at that time. Adapted from Sommer & Wurtz [8].