Pre-task prefrontal activation during cognitive processes in aging: a near-infrared spectroscopy study

Area of Science:

• Neuroscience
• Cognitive Aging Research
• Brain Imaging

Background:

• Cognitive function typically declines with age.
• The prefrontal cortex (PFC) is crucial for executive functions like prospective memory.
• Voluntary pre-task activation in the PFC may occur even during rest periods before cognitive tasks.

Purpose of the Study:

• To investigate age-related changes in voluntary pre-task activation within the PFC.
• To utilize a prolonged intertrial interval paradigm to better assess resting-state activation.
• To compare pre-task activation patterns between young and elderly adults.

Main Methods:

• Near-infrared spectroscopy (NIRS) was used to measure hemodynamic responses in 120 healthy adults (60 young, 60 old).
• Participants performed a working memory task with distinct resting and task periods.
• Data were normalized, and NIRS responses during baseline, pre-task (preT), early task (eT), and late task (dT) periods were analyzed using ANOVA.

Main Results:

• A significant interaction revealed smaller PFC hemodynamic responses during the preT period in the elderly compared to young adults.
• Conversely, elderly adults showed higher hemodynamic responses in the lateral PFC during the task period.
• Positive correlations were found between preT PFC hemodynamic changes and correct answer ratios in both age groups.

Conclusions:

• Increased pre-task activation in the anterior PFC is associated with enhanced cognitive performance.
• Diminished pre-task PFC activation may contribute to cognitive decline observed in aging.
• These findings highlight the role of preparatory neural activity in maintaining cognitive function across the lifespan.