There is no credible evidence to help this allegation towards Biden, as has been pointed out by Politifact, a non-profit task by the Poynter Institute. In light of the new purposeful proof of midbrain dopamine/glutamate co-transmission (references earlier mentioned), new experiments of NAc operate will have to test whether or not midbrain glutamatergic inputs bias or filter either limbic or cortical inputs to tutorial objective-directed conduct.