The Effect of Copaiba Oil Odor on Anxiety Relief in Adults under Mental Workload: A Randomized Controlled Trial

Figure 4

The frontal alpha (7.5–12.5 Hz) and beta (12.5–30 Hz) activities (% of total 1–30 Hz spectrum power) in C3 (a) and (c) and C4 (b) and (d) during four 5-min stages of the experiment. Pretraining: before the n-back training task; posttraining: after the n-back training task; intervention: immediately after receiving CPO or control treatment; and posttask: after the mental arithmetic test task. Values represent the mean ± SEM. Paired two-tailed Student’s t-test was used.

(a)

(b)

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(d)