Intraindividual variability in performance on associative memory tasks is elevated in amnestic mild cognitive...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Elevated intraindividual variability (IIV) indicates neurocognitive compromise.
• IIV is observed in reaction time tasks for individuals with mild cognitive impairment (MCI).

Purpose of the Study:

• To examine IIV on memory tasks sensitive to early cognitive change.
• To assess IIV in individuals with amnestic MCI compared to controls.

Main Methods:

• Administered computer-based associative recognition tests (word-word, face-name pairs).
• Derived accuracy, speed, and statistically purified IIV indices.
• Utilized logistic regression to analyze group membership prediction.

Main Results:

• The MCI group showed reduced accuracy and speed, and elevated IIV on both tasks.
• IIV, not speed, uniquely predicted group membership beyond accuracy.
• Elevated IIV in MCI aligns with neural network disturbance theories.

Conclusions:

• IIV is a sensitive indicator of cognitive decline in older adults.
• Findings support IIV's diagnostic implications for identifying MCI.
• IIV may reflect disruptions in medial temporal and frontal neural systems.