Human avoidance and approach learning: evidence for overlapping neural systems and experiential avoidance modulation of avoidance neurocircuitry.

Adaptive functioning is thought to reflect a balance between approach and avoidance neural systems with imbalances often producing pathological forms of avoidance. Yet little evidence is available in healthy adults demonstrating a balance between approach and avoidance neural systems and modulation in avoidance neurocircuitry by vulnerability factors for avoidance. Consequently, we used functional magnetic resonance imaging (fMRI) to compare changes in brain activation associated with human avoidance and approach learning and modulation of avoidance neurocircuitry by experiential avoidance. fMRI tracked trial-by-trial increases in activation while adults learned through trial and error an avoidance response that prevented money loss and an approach response that produced money gain. Avoidance and approach cues elicited similar experience-dependent increases in activation in a fronto-limbic-striatal network. Positive and negative reinforcing outcomes (i.e., money gain and avoidance of loss) also elicited similar increases in activation in frontal and striatal regions. Finally, increased experiential avoidance and self-punishment coping was associated with decreased activation in medial/superior frontal regions, anterior cingulate, amygdala and hippocampus. These findings suggest avoidance and approach learning recruit a similar fronto-limbic-striatal network in healthy adults. Increased experiential avoidance also appears to be associated with reduced frontal and limbic reactivity in avoidance, establishing an important link between maladaptive avoidance coping and altered responses in avoidance neurocircuitry.