Effort responses to suboptimal reward cues are related to striatal dopaminergic functioning
Motivation and Emotion (2014) - Comment
pubmed: 25400304  doi: 10.1007/s11031-014-9434-1  issn: 0146-7239  issn: 1573-6644 

Pascal Pas, Ruud Custers, Erik Bijleveld, Matthijs Vink