Table 4.

Spearman correlation coefficients of the relationship between fibromyalgia symptoms with the delta value of oxyhemoglobin (ΔHbO*) as cortical deactivation measure in either PFC or MC (n = 22).

	(1)	(2)	(3)	(4)	(5)
Portuguese Profile of Chronic Pain Screen (BP-PCP:S) total score (1)	1
Central Sensitization Inventory (BP-SCI) total score (2)	0.64**	1
ΔHbO* based on [HbO level before thermal stimuli onset minus HbO level 15 s after thermal stimuli end] on the left PCF (3)	0.40*	0.60**	1
ΔHbO* based on [HbO level before thermal stimuli onset minus HbO level 15 s after thermal stimuli end] on the right PCF (4)	0.09	0.24	0.80**	1
ΔHbO* based on [HbO level before thermal stimuli onset minus HbO level 15 s after thermal stimuli end] on the left MC (5)	− 0.06	0.18	0.48*	0.69**	1
ΔHbO* based on [HbO level before thermal stimuli onset minus HbO level 15 s after thermal stimuli end] on the right MC (6)	0.01	0.37	39	0.42	0.73**

Prefrontal cortex (PFC); motor cortex (MC). Correlation is significant at the 0.01 level (2-tailed); ΔHbO* in millimolar (mM).

**Correlation is significant at the 0.05 level (2-tailed).