Beta power

Fig. 2. Percent variation of beta rhythm in cirrhotic patients after a 1-week period of treatment with rifaximin (200-400 mg t.i.d.) or placebo. The relative beta power of the EEG decreased in the rifaximin-treated group (Wilcoxon paired test Z = 2.1, p = 0.03), but not in the placebo-treated group (Z = 1.07, p = nonsignificant) (from Del Piccolo et al. [40]).

The effects of kavain on human electrophysiology was examined in a double-blind, placebo-controlled study (Frey 1991). Dose-dependent increases were seen in delta, theta, and alpha 1 power, and decreases ocurred in alpha 2 and beta power. These changes were suggestive of a sedative effect of kavain, and were maximal in frontal areas. Interestingly, an initial activating effect was seen at the lowest dose (200 mg) but not at the largest dose (600 mg). 

Fig. 10-7. Composition and power emission from irradiated U fuel, (o) Power emission. Basis 1 beta particle of 0.35 Mev per disintegration 0.5 gamma photon of 0.7 Mev per disintegration beta power == gamma power = one-half total power, (b) Curie emission, (c) Fractional curie emission all beta emitters (except where noted y, meaning beta plus gamma emission). Key to curves on (c) (1) Te-129Y ...

The po-wer and Type II error rate (beta) Power and its related Type II error rate are probably the most neglected aspects of a statistical test. Power refers to the probability that a relationship in the population will be detected when one in fact exists. Therefore, power might reflect what R. A. Fisher called the "sensitivity" of an experiment (Fisher, 1942). Importantly, the power of an obtained statistical test reflects the probability that such a result can be replicated (Goodman, 1992). The effects of low statistical power on the reproducibility of research findings has been well documented (Goodman, 1992 Harris, 1997). The Type II error (beta) occurs when one fails to reject a felse null hypothesis. 

A significant result of Beta power was also observed at the Fp2 channel located at the right of the prefrontal lobe, as shown in Fig. 11.24. The mean of difference is over zero at 95% significance level, meaning that Pattern 2.1 evokes higher Beta fiequency power than Pattern 2.2 in this location of the brain. 

Figure 11.24 A significant result ot the Beta power corresponding to Patterns 2.1 and 2.2.

A significant difference of Beta power was observed at the 01 channel located at the left-hand side of the occipital lobe as shown in Fig. 11.30. The mean of the difference... 

Significant differences of Beta power were observed over the prefrontal lobe at the Fp 1 and Fp2 channels, on the right of the firontal lobe at the F4 channel, and on the left of the occipital lobe at the 01 channel, as shown in Fig. 11.36. The mean of the difference in the Fpl channel is over zero at 90% confidence level, which shows that Pattern 4.1 triggered significantly higher Beta power on the left of the prefrontal lobe. However, the mean of the difference in the Fp2, F4 and 01 channels is less than zero at 95% confidence level, meaning that Pattern 4.1 evokes lower Beta power on the right of the prefrontal and frontal lobes and in the left of the occipital lobe of the brain. 

Figure 11.36 Significant results of the Beta power corresponding to Patterns 4.1 and 4.2.

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