In delirium and Alzheimer’s disease (AD), which increase the risk for each other, patients suffer deficits in executive functions, including attentional control. There is a critical gap in our understanding of the mecha- nisms by which attentional control capacity may promote cognitive resilience in both delirium and dementia. Even under normal conditions neural resources for navigating the world around us are fundamentally limited (ie, we can’t attend to everything in our environment), yet attentional control allows the brain to effectively allocate neural resources to accomplish cognitive tasks. During stressors that limit neural resources further, eg neuro- inflammation after surgery or AD-related neurodegeneration, attentional control can compensate for neuronal injury to preserve cognitive function by marshaling remaining neural resources. Given the potential protective benefits of robust attentional control, this proposal introduces attentional resilience—ie the ability to retain robust attentional control despite physiological stressors—and evaluates its potential underlying neural mecha- nisms using the stressor of scheduled surgery in cognitively healthy older adults as a “natural experiment.” Our overall objective is to better understand the neural mechanisms underlying attentional resilience, which enable individuals to more effectively allocate neural resources to remain attentive to their surrounding environ- ment despite neuronal injury and/or neuro-inflammation. Our central hypothesis is that neural mechanisms underlying robust attentional control before surgery facilitate attentional resilience after surgery. Our aims eval- uate neural activity patterns that have been linked to robust attentional control. Given the well-established link between electroencephalogram (EEG) alpha (7-13 Hz) power and attentional control, Aim 1 focuses on the ability of attentional control processes to enable attentiveness by attenuating alpha power. In Aim 2, we explor