Functional near infrared spectroscopy activation during an executive function task differs between healthy older and...

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• Cognitive functions like processing speed and executive function can decline with age.
• Understanding the neurobiological basis of these age-related cognitive changes is crucial.
• Functional near-infrared spectroscopy (fNIRS) can examine cerebral oxygenation differences between age groups.

Purpose of the Study:

• To investigate differences in cerebral oxygenation between healthy older adults (OA) and younger adults (YA).
• To explore neurobiological underpinnings of cognitive changes in aging using fNIRS.
• To compare cognitive performance and brain activation during a measure of executive function.

Main Methods:

• Thirty-four participants (YA: mean age 28.1; OA: mean age 70.9) completed the Multi-Source Interference Task (MSIT).
• fNIRS recorded cerebral oxygenation over the prefrontal cortex during low and high-demand cognitive interference conditions.
• Behavioral data (accuracy, reaction time) and functional activation patterns were compared between groups.

Main Results:

• OA exhibited slower reaction times and lower accuracy than YA during the high-demand interference condition.
• An age-related increase in oxygenated hemoglobin (HbO) was observed in OA during both conditions (p < 0.05).
• OA showed greater activation during the control condition, while YA showed greater activation during the interference condition.

Conclusions:

• Older adults recruit additional neural resources (increased HbO) to maintain performance on tasks with low cognitive interference.
• Compensatory mechanisms in older adults may be insufficient to support behavioral performance under high cognitive load.
• These findings highlight age-related differences in neural recruitment strategies during executive function tasks.