Figure 3.
Population contrast responses of V4 neurons (n = 78). The same format as in Figure 2, A and D, is shown. Histograms were smoothed with a Gaussian filter (4 ms SD). A, Population average responses of V4 neurons. The black arrow in the top panel points to elevated spontaneous activity caused by attention. Latency values for the attended and unattended conditions were as follows: 100% contrast, 62 and 63 ms; 25% contrast, 73 and 74 ms; 6.2% contrast 96 and 85 ms; 1.6% contrast, 209 and 144 ms. B, Normalized average responses of V4 neurons. The response of each neuron was normalized to its maximum response magnitude over all trials. Horizontal lines show normalized response magnitudes of the population. Latency values for the attended and unattended conditions were as follows: 100% contrast, 65 and 64 ms; 25% contrast, 76 and 77 ms; 6.2% contrast 96 and 86 ms; 1.6% contrast, 192 and 139 ms.