The revised reinforcement sensitivity theory (rRST) of personality has conceptualized three main
systems: the behavioural approach system (BAS), behavioural inhibition system (BIS), and fightflight-
freeze system (FFFS). Research links greater relative left-frontal activity with BAS-related
tendencies and impulsivity and greater relative right-frontal activity with “withdrawal” motivation
that included both BIS and FFFS. Although rRST has addressed the separation of FFFS and BIS,
much of personality neuroscience research does not indicate which system is related to right frontal
activity. We administered the Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ)
to measure the BAS and its facets (goal-drive persistence, reward interest, reward reactivity, and
impulsivity), BIS, and the withdrawal FFFS. We examined the association of RST-PQ traits with resting
electroencephalogram (EEG) alpha-asymmetry in female participants (N = 162) by considering the
influence of experimenter’s gender. In the total group, that included two subgroups with experimenters
of different gender, BAS-impulsivity was related to greater left- than right-frontal activity, and
FFFS, but not BIS, was related to greater relative right-frontocentral activity. These associations
remained significant for the subgroup with a young same-sex experimenter, but not with opposite-sex
experimenter
