Dorsolateral prefrontal lobe activation declines significantly with age--functional NIRS study

Area of Science:

• Neuroscience
• Cognitive Aging
• Medical Imaging

Background:

• Cognitive function, particularly working memory, relies on the dorsolateral prefrontal cortex (DLPF).
• Age-related changes in cerebral blood flow and cognitive performance are well-documented.
• Non-invasive neuroimaging techniques are crucial for understanding brain function across the lifespan.

Purpose of the Study:

• To quantitatively assess dorsolateral prefrontal cortex (DLPF) activation during working memory tasks in healthy individuals across a wide age range.
• To investigate the relationship between age and DLPF activation.
• To evaluate the utility of functional near-infrared spectroscopy (fNIRS) for measuring age-related changes in brain activation.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) was employed to measure DLPF activation.
• Participants included cognitively normal individuals aged 20-90 years.
• A DLPF activation score (DAS) was calculated and analyzed in relation to age.

Main Results:

• A significant decline in DLPF activation score (DAS) was observed as a function of age (r(2) = -0.561, p < 0.05).
• This indicates a reduced blood flow response associated with DLPF activation in older, cognitively normal individuals.
• fNIRS proved to be a convenient and portable tool for assessing this age-related decline.

Conclusions:

• Cerebral blood flow response in the DLPF decreases with advancing age in cognitively normal individuals.
• fNIRS is a viable method for monitoring age-related changes in DLPF function.
• These findings contribute to understanding cognitive aging and the neurophysiological underpinnings of working memory.