Prefrontal activation patterns of automatic and regulated approach–avoidance reactions – A functional near-infrared spectroscopy (fNIRS) study

Abstract

IntroductionThe present pilot study investigated cortical processes during automatic and regulated approach–avoidance reactions for the first time. Methods 1In 15 healthy volunteers, prefrontal activity was measured with functional near-infrared spectroscopy (fNIRS) during performance of a joystick version of the Approach–Avoidance Task (AAT). In experiment 1, participants approached (pulled towards their body) and avoided (pushed away from their body) positive and negative pictures. Results 1Incompatible, regulated reactions (avoid positive, approach negative) compared to compatible, automatic reactions (approach positive, avoid negative) caused stronger activation in terms of a decrease of deoxygenated haemoglobin (HHb) in right dorsolateral prefrontal cortex (DLPFC) (i.e., in one of the main instances for behavioural control in humans). Methods 2In the context of pathologically enhanced approach tendencies in addiction disorders and of planned future studies, we presented alcohol and non-alcohol pictures in experiment 2. Results 2Here, left anterior lateral orbitofrontal cortex as part of the general reward system processing secondary rewards showed stronger activation in terms of increased oxygenated haemoglobin (O2Hb) during approaching compared to avoiding alcohol pictures. This difference was positively correlated with participants’ expectation about beneficial effects of alcohol in terms of emotional regulation. DiscussionDespite some limitations due to the pilot character of the study, our results suggest that further combinations of the AAT and functional imaging methods will reveal detailed insight into neuronal mechanisms constituting approach–avoidance as basic behavioural principles and into specifically altered sub-processes in alcohol dependence.