Acute stress increases left hemispheric activity measured via changes in frontal alpha asymmetries

Figures

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  Figure 1. Physiological and subjective stress reactions in the TSST and P-TSST sessions Error bars represent 1 ± SE of the mean (SEM). The first measurement was taken immediately before the TSST or P-TSST preparation period. (A) Mean log-transformed cortisol in relation to measurement time point. (B) Mean salivary alpha amylase response in relation to measurement time point. (C) Mean subjective stress responses measured by SERS in relation to measurement time point.

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  Figure 2. Results of the EEG recordings (A) Alpha asymmetry indices for the stress (TSST) and no stress (P-TSST) condition over frontal and occipital electrodes. Solid colors indicate AIs during stress induction, whereas hatched colors show AIs during rest. Over the F3/F4 electrode pair, we found more positive AIs in the TSST compared to the P-TSST session indicating stronger left-hemispheric activation during stress induction. On the O1/O2 electrode pair, we found the opposite effect. Error bars represent ±1 SEM ∗ reflect significant differences with p < 0.05. (B) Alpha power distribution across the skull. Electrodes of interest are highlighted. Please note that the frontal view is laterally reversed. During the TSST, there was stronger right frontal alpha power compared to P-TSST condition whereas we found stronger left frontal alpha power over occipital sites during stress. During resting state, there were no significant differences between the TSST and P-TSST conditions.