Differences in electroencephalography oscillations between normal aging and mild cognitive impairment during semantic...

Area of Science:

• Neuroscience
• Cognitive Aging
• Electrophysiology

Background:

• Semantic memory is crucial for cognition, remaining stable in healthy aging but declining in neurodegenerative diseases.
• Understanding age-related changes in semantic memory retrieval is vital for distinguishing normal aging from pathological conditions.

Purpose of the Study:

• To investigate electroencephalography (EEG) oscillatory patterns during semantic memory retrieval in young adults, healthy aging adults, and individuals with mild cognitive impairment (MCI).
• To identify neural correlates of normal aging and pathological aging effects on semantic memory retrieval.

Main Methods:

• EEG recordings were obtained during a semantic memory retrieval task involving word-pair judgments.
• Event-related power changes in theta, alpha, and beta frequency bands were analyzed to compare young adults (YA) vs. healthy aging adults (HA) and HA vs. MCI.
• Behavioral accuracy and EEG oscillations were correlated to assess their relationship with cognitive performance.

Main Results:

• Healthy aging adults (HA) showed distinct high-beta activity compared to young adults (YA), while YA exhibited later theta and alpha differences.
• Mild cognitive impairment (MCI) patients displayed altered early event-related beta power patterns and reduced retrieval accuracy compared to HA.
• Beta oscillations were specifically correlated with behavioral performance in healthy aging adults.

Conclusions:

• The aging brain increasingly relies on faster beta oscillations for semantic memory retrieval.
• Pathological aging, as seen in MCI, is associated with declining retrieval accuracy and altered beta oscillation patterns.
• These findings offer insights into age-related neural mechanisms of semantic memory and potential biomarkers for early pathological aging detection.