Abstract
Coronary artery disease (CAD) is a diverse clinical impairment that impacts not only vascular integrity but also elicits wide-ranging changes to central nervous system (CNS) structures. In particular, recent neuroimaging work by our group has shown that some persons with CAD exhibit cortical atrophy in the frontal brain structures supporting goal-directed movements (Goswami et al. 2011: Neuroimage). To address the behavioral consequences of cortical atrophy, the present study contrasted pro- and antisaccade latencies in persons with CAD (N = 10) and age-matched controls (N = 15). Importantly, we contrasted pro- and antisaccades between-groups to determine whether CAD differentially impacts stimulus-driven (i.e., prosaccades) and intentionally mediated (i.e., antisaccades) oculomotor networks. Surprisingly, results indicated that neither pro- nor antisaccade reaction times (RTs) differed between groups (ts < 1). Subsequently, we sought to determine whether a co-morbidity of CAD contributes to the above-mentioned changes in CNS structures. As such, we used the same pro- and antisaccade task in a corpus of individuals (N=13) falling under the clinical spectrum of mild-cognitive impairment (MCI). Results showed that persons with MCI elicited a marked increase in pro- and antisaccade RTs relative to the CAD group and their age-matched controls. That persons with MCI exhibit increased pro- and antisaccade planning times suggests that sensory- and intentionally-based actions are delayed even when an individual is in the very early stages of cognitive decline. Most notably, the present results suggest that a simple oculomotor task may provide the basis for identifying persons at risk for MCI.Acknowledgments: Supported by the Canadian Institutes for Health Research and the Natural Sciences and Engineering Research Council of Canada.