Neuropsychological and Morphometric Correlates of Decision Making with the Coin Flip Task

The purpose of this study was to determine how older adults perform on a decision- making task (referred to as the Coin Flip Task), and how this performance correlates with demographic, neuropsychological, and brain morphometry variables. The study of decision making ability among older adults is important for several reasons. First, older adults frequently make “weighty” decisions as they age, such as important financial and medical decisions. When less than optimal decisions are made, it is difficult for the older adult to recover from or fix that decision given their relatively limited longevity. Second, decision making ability emanates from a brain area (the prefrontal cortex) that is known to undergo the greatest age-related decline in normal aging, making sound decision making that much more crucial. From a biomedical perspective, understanding the mechanisms of how people age can help medical personnel to better tailor medicine and engineer devices that can assist the elderly in their lives and assure that they are well cared for. In the current study, 55 community dwelling, healthy older adult participants visited our laboratory for a series of visits that assessed their cognitive health, measured their decision-making abilities, and measured their brain’s structure and functioning. First, participants’ Coin Flip performance was analyzed. We did this a number of ways. One approach was to subdivide our sample into three clusters that varied based on their Coin Flip behavior (i.e., H-T-NG = poor decision makers; H-T= mildly advantageous decision makers; H/T= advantageous decision-makers). Next, we looked at associations between participants’ coin flip performance and their demographic and neuropsychological data. Several relationships between Coin Flip performance and the neuropsychological variables were identified, including findings involving both cognition and psychological/personality variables. On the cognitive side, more advantageous Coin Flip performances was positively associated with psychomotor speed, executive functioning, and interoceptive sensitivity, to name just a few. On the psychological/personality side, more advantageous Coin Flip performances was negatively associated with self-reported anxiety. Finally, we correlated Coin Flip performance with cortical thickness. That analysis revealed several significant findings. One particularly robust finding indicated that older adults with more advantageous Coin Flip Task performance displayed greater cortical thickness an area of the prefrontal cortex, called the superior frontal region. The results are discussed in the context of the literature on the cognitive neuroscience of aging. Study limitations and future directions are also addressed.