Anticipatory stress increases and trait anxiety decreases neural regulatory activity indicated by delta-beta coupling

The anticipation of oncoming threats is emotionally challenging and related to anxiety. The current study aimed to investigate the neural regulatory processes during the anticipatory preparations in stressful situations in relation to trait anxiety, especially in an uncertainty-related stressful situation. To this end, we measured within-subject delta-beta amplitude-amplitude correlation (AAC) and phase-amplitude coupling (PAC) with electroencephalography using a well-defined stress-inducing paradigm in 28 high-trait-anxiety (HTA) and 29 low-trait-anxiety (LTA) college students. Specifically, we included certain, uncertain, and no threat conditions, as well as a resting state. Results showed a generally larger parietal delta-beta AAC in the LTA group relative to the HTA group, supporting the hypothesis that delta-beta AAC reflects the efficiency of stress regulation and the compromised effect of trait anxiety. An increased delta-beta AAC was also found under the (un)certain threat conditions at the frontal site and uniquely under the uncertain threat condition at the parietal site relative to the resting state, indicating stress-related and especially uncertainty-related mobilization of regulatory activity. The investigation of delta-beta PAC revealed similar patterns. That is, a tendency towards a larger frontal delta-beta PAC in the LTA group relative to the HTA group, as well as increased delta-beta PAC under the (un)certain threat conditions at the parietal site, and at the frontal site under the uncertain threat condition only, relative to the resting state. These findings demonstrate a general condition-independent decreasing effect of trait anxiety in mobilizing neural regulatory activity, as well as an increasing effect of stressful situations, especially for uncertain threats.