Fig. 5.

The effects of OLBNP at 0.03, 0.05, and 0.10 Hz on functional hyperemia measured by the OCBF power near 0.0083 Hz due to AF. Data are averaged over all subjects. A: AF is compared with the absence of flexion (baseline, solid bars) and is shown as a log₁₀ of OCBF power during flexion − log₁₀ of OCBF power at baseline, or equivalently 10 × log₁₀(flexion/baseline) in decibels. Similarly, OLBNP with AF is compared with AF alone (open bars) = 10 × log₁₀(OLBNP + flexion/flexion), which is a negative quantity (OLBNP reduces flexion power). The net effect of first flexion and then OLBNP + flexion is equal to the sum of the logarithmic effects = log₁₀(flexion/baseline) + log₁₀(OLBNP + flexion/flexion) = log₁₀(OLBNP + flexion/baseline) and is close to zero. Therefore, oscillatory power is reduced nearly to baseline by 0.05 Hz (P < 0.01) and 0.10 Hz (P < 0.001) LBNP oscillations. B: the effect on OCBF power near 0.0083 Hz of adding AF (open bars) after first applying and maintaining OLBNP at 0.03, 0.05, and 0.10 Hz (shaded bars). There is no significant direct effect of OLBNP oscillations alone on OCBF power at 0.0083 Hz, and no significant effect of AF on OCBF power at 0.0083 Hz in the presence of OLBNP. Values are means ± SE. *Significant difference of the comparison.