EEG asymmetry responses to lavender and rosemary aromas in adults and infants.
Frontal EEG asymmetry shifting from baseline was examined in adults and infants exposed to lavender and rosemary by reanalyzing previously published data, using techniques different from those utilized in the original two studies. Results from Study 1 on 39 adults revealed significant EEG shifting in the lavender group, with greater relative left frontal EEG activation (associated with greater approach behavior and less depressed affect). The participants in the two aroma groups were further grouped by those with greater baseline, relative to left frontal EEG activation, versus those with a greater baseline, relative to right frontal activation. Collapsing across aroma groups, those with greater baseline, relative to right frontal activation, shifted left during the aroma. Those with greater baseline relative to left frontal activation did not change. In the rosemary group, those with greater baseline relative to right frontal EEG activation shifted left during the aroma, while those with greater baselines relative to left frontal EEG activation shifted right. In the lavender group, those with greater baselines relative to right frontal baseline EEG activation shifted left, but those with greater baselines relative to left baseline did not shift. Study 2 on 27 full-term newborns revealed no significant shifts in asymmetry in either aroma group. However, when the aroma groups were collapsed, the right frontal EEG group exhibited significant shifting relative to left frontal EEG activation. This finding was similar to the adult findings, suggesting that either lavender or rosemary may induce left frontal EEG shifting in adults and infants who show greater baselines relative to right frontal EEG activation.