Our current research focuses on the role of motivation and cognitive control in mediating changes in the psychological and neural mechanisms of older adult decision-making. Cognitive control refers to a collection of processes that structure behavior in accordance with internal goals, thereby enabling goal-driven processes to compete effectively with processing tendencies driven by habits and other types of reflexive, stimulus-evoked impulses. Changes in the operation of control processes appear to represent a fundamental component of age-related cognitive decline. Our prior work has suggested that older adults suffer from a reduced ability to actively maintain and utilize goal-related representations in a proactive fashion, and that this deficit is directly related to underlying neurobiological changes in the functioning of the mid-brain dopamine system and its interaction with the lateral prefrontal cortex (PFC) and medial frontal cortex (MFC). A related and critical issue that we and our colleagues have recently highlighted, and which has attracted accelerating research attention, is the interaction of motivation and cognitive control. In particular, it has become increasingly appreciated that cognitive control processes can be strongly modulated – and even governed – by the current motivational context, or more specifically, the reward (and punishment value) of task goals and action outcomes. A growing body of work has provided evidence that experimental manipulations of motivational value can substantially impact the performance of cognitive tasks with high control demands, and that these effects are mediated by changes in in the medial and lateral PFC (plus other components of the brain frontoparietal control network), most likely through changes in signaling through dopaminergic reward circuits (e.g., involving ventral striatum [VS] and ventromedial PFC.
A unifying theme of the proposed studies is the use of the discounting framework. This framework provides a means of formally modeling how various cost factors, such as the delay, probability, or cognitive effort, are combined with the size of the outcome to determine its (discounted) subjective value, and whether choices involving gains and losses differ in this regard. The proposal extends our previous collaborative efforts using this framework to a series of studies that integrate behavioral, mathematical modeling, and neuroimaging methods. A key feature of these studies is the use of innovative experimental paradigms that enable discovery of fundamental components of economic decision-making, as well as determination of how cognitive control interacts with affective and motivational factors, and how these components and their interaction are affected by advancing age. The findings of these studies promise to provide critical new data regarding economic choice behavior in older adults, which might be used to develop interventions that can promote adaptive decision-making throughout the life course.
Supporting grant: Interactions of Motivation and Cognitive Control in Older Adult Decision-Making 5R21AG058206 (Braver, PI)