Table 3.

Average BOLD response amplitude (%) from activated voxels during the motor (FTAP), cognitive (DSST) and hypercapnia (BH) task in the younger and older subjects.

Subject	Young			old
	FTAP	DSST	BH	FTAP	DSST	BH
1	3.27	3.56	4.78	----	----	----
2	2.62	3.78	5.26	3.00	5.91	4.95
3	2.58	4.96	7.14	1.64	2.79	6.18
4	3.6	3.12	5.55	2.36	2.86	3.91
5	2.47	3.16	4.15	2.94	5.12	6.05
6	3.39	4.48	9.20	5.94	4.12	5.64
7	2.35	3.12	4.16	8.91	2.90	6.84
8	2.94	3.75	4.79	3.28	3.83	3.89
9	3.15	3.42	5.51	3.68	3.77	7.45
10	1.83	6.81	4.91	2.04	3.22	6.05
11	2.71	4.00	4.17	2.71	4.44	7.37
12	2.69	3.12	4.70	3.70	4.17	4.62
Mean	2.80	3.94	5.36	3.65	3.92	5.72
SD	0.49	1.10	1.46	2.07	0.99	1.25
CV	0.18*	0.28**	0.27§	0.57	0.25	0.22

Significantly different compared to older,

^*P<0.0001,

Not significant compared to older

^**P< 0.73 and

^§P< 0.6

Bartlett’s test of equality of variance.