Abnormal medial prefrontal cortex activity in heavy cannabis users during conscious emotional evaluation.
Psychopharmacology March 1, 2016 Michael J Wesley, Joshua A Lile, Colleen A Hanlon et al.
Long-term heavy cannabis users who are not acutely intoxicated show diminished brain responses in the medial prefrontal cortex (mPFC) when consciously evaluating emotional images, compared to non-users. Both groups judged the same stimuli as emotional and had similar activations in visual, midbrain, and middle cingulate cortices. However, controls showed additional amygdalar and inferior frontal gyrus activations, while cannabis users showed mPFC deactivations during emotional evaluation. Between-group comparisons found mPFC activity during positive and negative evaluation was significantly hypoactive in cannabis users. This abnormal neural processing of affective content extends to conscious evaluation and resembles attenuated mPFC responses found during increased non-affective cognitive load.