Table 2. Spectral analysis of LD signal during PORH response.

	ULF power 0.0095–0.02 Hz [n.u.]	VLF power 0.02–0.06 Hz [n.u.]	LF power 0.06–0.15 Hz [n.u.]	HF power 0.15–0.6 Hz [n.u.]
Before ingestion	24.5 ± 3.4	22.3 ± 2.2	19.2 ± 2.0	11.4 ± 0.8
30 min after caffeine	26.6 ± 4.2	25.6 ± 2.6	27.0 ± 3.7*	11.0 ± 1.5
60 min after caffeine	20.9 ± 3.2	23.4 ± 1.9	28.8 ± 3.0*	13.1 ± 1.8

ULF–ultra-low frequency; VLF–very-low frequency; LF–low frequency; HF–high frequency; n.u.–normalized units

*–statistically significant difference before and after ingestion of caffeine (p < 0.05).

Data are expressed as means ± SE.