Psychophysiological Responses to Stress Related to Anxiety in Healthy Aging: A Near-Infrared Spectroscopy (NIRS) Study

The aim of the study was to explore the effects of situational stress and anxiety in a group of healthy elderly, both in terms of psychophysiological correlates and cognitive performance. Eighteen participants (Mage = 70 ± 6.3; range 60-85) were assessed for anxiety and were instructed to perform a computerized math task, under both a stressful and a control condition, while near-infrared spectroscopy (NIRS) signal and electrocardiography (ECG) were recorded. NIRS results evidenced an increased activation of right PFC during the entire procedure, even if effect sizes between left and right channels were larger during the experimental condition. The amount of right activation during the stressful condition was positively correlated with anxiety. Response times (RTs) were slower in more anxious than in less anxious individuals, both during the control and stressful conditions. Accuracy was lower in more anxious than in less anxious individuals, only during the stressful condition. Moreover, heart rate (HR) was not modulated by situational stress, nor by anxiety. Overall, the present study suggests that in healthy elderly, anxiety level has a significant impact on cerebral responses, and both on the amount of cognitive resources and the quality of performance in stressful situations.