5‐ HTTLPR and anxiety modulate brain‐heart covariation

To date, little is known about genes affecting the interplay of brain and heart activity. Because serotonin (5‐ HT ) is involved in corticovagal neurotransmission, we tested whether the 5‐ HT transporter polymorphism 5‐ HTTLPR affects brain‐heart covariation. Further, associations with neuroticism/anxiety ( NANX ) were tested, as anxiety is related to 5‐ HT and neurogenic changes of heart period ( HP ). N  = 168 participants performed a time‐estimation task while EEG and HP were recorded. Brain‐heart covariation was measured using time‐lagged within‐subject correlations of centromedial feedback‐evoked single‐trial EEG at 300 ms and subsequent changes of HP . EEG ‐ HP correlations were higher in 5‐ HTTLPR long allele carriers. Moreover, after negative feedback, EEG ‐ HP correlations and feedback‐related negativity amplitudes independently correlated with NANX . The results indicate that individual differences in brain‐heart covariation relate to 5‐ HT and NANX .