Impairment in anticipatory cognitive brain processing in frail older adults

Frailty of the elderly is a condition that incorporates multisystem physiological age-related impairments with poor clinical and functional outcomes. Literature shows that this condition could be associated with cognitive deterioration due to the degeneration of brain structures and functions, especially in the prefrontal cortex (PFC). Despite the interest in this condition, research on cognitive performance and brain activity in frailty remains limited. The purpose of the present study was to use the event-related potential (ERP) method to investigate the frontal and prefrontal brain activity of frail elderly people during the anticipatory phase of a cognitive task. ERPs of 38 frail and pre-frail participants (Frail group) aged ≥ 65 years, and a group of 38 matched robust individuals were compared. Cognitive functions were also assessed using the Montreal Cognitive Assessment (MoCa); anxiety was evaluated with the State-Trait Anxiety Inventory (STAI). Results showed that in the Frail group, the activity from the PFC was lower than in the Robust group. This reduction of top-down cognitive control may have produced, in the frail participants, greater response errors and anxiety levels higher than those of the Robust group. Results suggest that PFC degeneration may reduce the cognitive readiness preceding a cognitive task, which is necessary for accurate task performance. This PFC hypoactivity may also lead to increased anxiety levels in frail people. Considering that this effect was of similar magnitude in frail and pre-frail participants, the anticipatory ERP activity of the PFC could be a potential neuromarker of frailty.