Distinguishing Between Genuine and Feigned Dementia Using Event-related Potentials

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysiology

Background:

• Individuals with probable Alzheimer disease (AD) may underperform on memory-based validity tests.
• Event-related potentials (ERPs) have shown promise in detecting feigned cognitive impairment in younger populations.

Purpose of the Study:

• To assess the effectiveness of an auditory oddball task and P3b peak amplitude in distinguishing probable AD from simulated dementia.
• To evaluate the P3b peak amplitude as a physiological marker for cognitive impairment.

Main Methods:

• Twenty individuals with probable AD and 20 healthy controls (HC) participated.
• HC simulated dementia in one condition and performed honestly in another; probable AD participants performed honestly.
• An auditory oddball task, P3b peak amplitude, and Test of Memory Malingering (TOMM) were administered.

Main Results:

• P3b peak amplitude remained stable in HC across conditions.
• Combining P3b peak amplitude with TOMM Trial 2 scores achieved 100% sensitivity and 90% specificity in differentiating probable AD from simulated dementia.

Conclusions:

• P3b peak amplitude is an effective physiological measure for cognitive impairment in probable AD.
• The combination of P3b peak amplitude and TOMM Trial 2 scores shows potential as a performance validity measure for differentiating probable AD from simulated dementia.