This reward benefit effect on latency was highly significant ( F (2,53) = 35.855, p < 0.0001), amounting 31 ms for young adults ( F (1,17) = 13.95, p < 0.002), 30 ms for healthy elderly ( F (1,17) = 6.428, p < 0.022), and 28 ms for PD patients ( F (1,19) = 15.226, p < 0.001).
Specific preparation also had significant effects on antisaccade accuracy ( F (2,53) = 12.882, p < 0.001) with a spatial preparation benefit of 4.5% for young adults ( F = 10.289, p < 0.005) and a marginally significant benefit of 2.5% for healthy elderly ( F = 3.518, p < 0.079) and a benefit of 3.9% for PD patients ( F = 3.330, p < 0.085), although no significant differences between groups were indicated ( F (2,53) = 0.541, p < 0.586, see Figure 4 B).