Fig. 4. Decay of blood oxygenation level–dependent signals after the end of stimulus or task. Pain-related signals (filled circles; n = 79) decayed more rapidly than visual and motor task-related signals (open circles; n = 48). Signal intensities were averaged and compared with the maximum (max) during the on phase across all the voxels of interest in all subjects. Bars represent SEM. *P < 0.05; †P < 0.005; ‡P < 0.0001 against the maximum by repeated-measures analysis of variance and a post hoc  Fisher protected least significant difference test for multiple comparisons.