Neural firing activity in delayed-response task in which a motion stimulus presentation is followed by a memory period. A, Sample time courses within a trial with different coherence levels. Black and dashed lines are for saccades moving toward and away from the response field of the neuron, respectively. The coherence level is shown at the top of each panel. Shaded regions, Motion viewing period. The black horizontal line at the bottom indicates the time epoch when the two firing rates are indistinguishable. B, Dependence of neural activity on motion strength in different epochs. Opened and filled circles, Saccades toward and away from the response field of the neuron. The largest dependence on the motion strength, as well as the greatest difference in the two neural responses, correspond to the late phase (0.5–1 s epoch) of stimulus presentation. In the third epoch (early delay period), there is a still a residual effect of the dependence of neural response on motion strength. Figures are calculated using correct trials only and averaged over 2000 trials.