Figure 3.

False‐positive rates for three tests and three noise estimates vs. the nominal significance level for actual noise data. A: Test 1 (no assumed form). B: Test 2 (assumed peak values). C: Test 3 (assumed hemodynamic shape). Similar to the synthetic data, not estimating the noise parameters produced false‐positive rates substantially greater than nominal values, although Test 2 was least sensitive. The false‐positive rates were slightly greater than nominal rates even when the noise was estimated. Values above the shaded region are inappropriately high, while values in the shaded region are too low.