Comments and controversies: Piecing together the neurobiology of decision-making.

In this paper, we address issues raised by Tierney and Hart (Assessing Complex Cognitive Functioning Requires Multiple Tasks) in response to our recently published findings showing that less advantageous decision-making on the Iowa Gambling Task (IGT) was associated with enhanced right ventral striatal dopamine response to intravenous amphetamine (Oswald et al., 2015). We agree with the overall premise of the paper, which was that decision-making involves multiple components, which may not be tapped by a single measure. While Tierney and Hart also bring up some important issues related to the construct validity of the IGT, we suggest that they are failing to put the findings within the context of the growing body of research that has highlighted the role of DA function in risk-taking behavior across species using a variety of tasks. It should also be noted that it was not our goal to "cover all bases" within the context of a single study. Nevertheless, we appreciate the discussion, which we believe highlights the need for further empirical refinement of the construct to facilitate detection and understanding of the differential role that specific molecular mechanisms may play in the component processes.