J Korean Sleep Res Soc.  2014 Jun;11(1):5-10.

Caffeine Maintains Arousal Level and Prevents Change of Electroencephalogram Spectral Powers with Time at Rest

• Jung JY
• Lee HW
• Jang IS
• Suk K
• Lee MG

Abstract

OBJECTIVES
Although many studies have used quantitative electroencephalography (qEEG) analysis, some inconsistencies remain regarding the effects of caffeine. Among variables producing inconsistencies, the effect of selecting analyzing segment on caffeine study was examined by comparing the first and second halves of a recording session.
METHODS
Eleven subjects underwent two EEG recording sessions for decaffeinated (control group) and caffeinated coffee (caffeine group) with at least a 48 hr interval. The log absolute powers (BA) and log relative powers ratio (BRr) of 8 frequency bands were compared between groups and between the first 5-min (c1) and second 5-min (c2) recording segments.
RESULTS
As BA's were compared between groups, Delta2 and Theta1 were lower at both segments in the caffeine group and these differences were greater at c2. Increased differences were mainly due to temporal change in the control group. As BRr's were compared, Delta2 was lower at both segments and the difference was greater at c2 in the caffeine group. Theta1 was lower at c2, Beta BRr was higher at c1, while Alpha2 BRr was higher at c2 in the caffeine group. The dissimilarity indices between groups increased about two-fold with. The dissimilarity indices between segments were about three-times larger in the control group than in the caffeine group.
CONCLUSIONS
The results indicate that selection of analyzing segment is one important factor for quantitative EEG, and suggest that caffeine prevent decline of arousal, and that the simple 'dissimilarity index' can well represent the effect of caffeine on EEG spectral powers.

Keyword

Band absolute power; Band relative power; Topographic map; Caffeine; Dissimilarity index

MeSH Terms

Arousal*
Caffeine*
Coffee
Electroencephalography*
Caffeine
Coffee