Table 3.

Results of a hierarchical linear regression used to determine the unique and shared variance in anxious temperament accounted for by the mean 5-HTT availability and FDG metabolism within each cluster

Brain region	Hemisphere	Total variance in anxioustemperament accountedfor by FDG(NEC) and 5-HTT			5-HTT unique variance			FDG(NEC) unique variance			Shared variance
		R2	F	p	ΔR2	F	p	ΔR2	F	p	R2 − ΔR2
Amygdalohippocampal area	Left	0.434	11.890	0.0002	0.118	6.489	0.016	0.191	10.459	0.003	0.125
BNST	Left	0.369	9.078	0.001	0.179	8.804	0.006	0.119	5.868	0.021	0.071
Hippocampus	Left	0.348	8.259	0.001	0.130	6.187	0.018	0.129	6.131	0.019	0.089
Genu of corpus callosum	Midline	0.346	8.208	0.001	0.070	3.325	0.078	0.124	5.868	0.021	0.152
Amygdalohippocampal area	Right	0.362	8.783	0.001	0.116	5.635	0.024	0.074	3.588	0.068	0.172
BNST	Right	0.369	9.077	0.001	0.101	4.943	0.034	0.130	6.385	0.017	0.138
Hippocampus	Right	0.453	12.857	0.0001	0.199	11.305	0.002	0.224	12.693	0.001	0.030

The FDG values were taken from the NEC component of the behavioral paradigm and therefore represent glucose metabolism in response to a potential threat.