Table 1.

Activated voxels in the condition “CO₂ vs. baseline” (main effects)

Anatomical brain area	Peak coordinates (Talairach‐space) in mm			Statistical Z value	Voxel P value
	x	y	z
Right parietal operculum	56	−8	12	7.67	0.000
Right postcentral gyrus	48	−12	22	6.87	0.000
Right postcentral gyrus	54	−12	30	6.62	0.000
Left superior ternporal gyrus	−66	−4	8	6.85	0.000
Left planum polare, transition between STG and insula	−40	0	−10	5.90	0.000
Left postcentral gyrus	−46	−12	36	5.76	0.000
Bilateral supplementary motor area (SMA)	8	−4	64	4.52	0.001
Left anterior cingulate gyrus	−8	14	28	3.70	0.006a
Right medial temporopolar region and piriform cortex	22	10	−18	3.61	0.001a
Left piriform cortex	−26	2	−18	3.30	0.010a

STG: superior temporal gyrus.

Coordinates [interpreted according to Mai et al., 2004] represent the centres of activation with the corresponding clusters reaching out farther.

^aConfirmed by small volume correction [Worsley et al., 1996].