Age-Related Changes in Physiological Reactivity to a Stress Task: A Near-Infrared Spectroscopy Study.

Area of Science:

• Neuroscience
• Gerontology
• Psychophysiology

Background:

• Aging is linked to diminished cardiovascular responses during stress.
• The impact of age on prefrontal cortex (PFC) reactivity to acute stressors remains less understood.

Purpose of the Study:

• To examine how a controlled stress task affects PFC and autonomic system activity in older versus younger adults.
• Investigate age-related differences in physiological and cortical responses to acute stress.

Main Methods:

• Recruited 55 healthy adults (26 older, 29 younger), balanced for sex.
• Utilized a computerized stress task with control and experimental (timed mental arithmetic) conditions.
• Measured physiological data using near-infrared spectroscopy (NIRS) for PFC activity and ECG for heart rate.

Main Results:

• Significant group-by-condition interactions observed in heart rate, PFC oxyhemoglobin (Oxy-Hb), and performance.
• Younger adults showed increased heart rate and bilateral PFC Oxy-Hb during stress; older adults did not.
• Older adults demonstrated poorer performance (lower accuracy, slower response times) under stress.

Conclusions:

• Cardiovascular and cortical reactivity to stress are age-dependent.
• Older adults display reduced physiological reactivity to acute stressors, suggesting impaired adaptive capacity.
• Further research is needed to explore the mechanisms behind age-related changes in prefrontal and cardiovascular stress responses.