Clinical Manifestations

Area of Science:

• Neuroscience
• Cognitive Psychology
• Alzheimer's Disease Research

Background:

• Individuals at high risk for Alzheimer's disease (AD) exhibit attentional processing deficits.
• Attentional mechanisms are hypothesized to influence implicit task performance, especially under high cognitive load.
• Previous studies link pathological CSF amyloid/tau ratios to altered attention in high-risk individuals.

Purpose of the Study:

• To investigate if attentional mechanisms modulate implicit task performance in high-risk AD participants.
• To examine neural responses during varying attentional loads in individuals at high risk for AD.
• To determine if high attentional load exacerbates performance deficits in implicit tasks for high-risk individuals.

Main Methods:

• Electroencephalography (EEG) data collected during a Simon task with varying attentional loads (high vs. low).
• Participants responded to arrow stimuli, with primes (congruent/incongruent) presented beforehand.
• Analysis focused on behavioral responses and event-related potentials (ERPs), specifically N200 and P300 components.

Main Results:

• Both high and low-risk groups demonstrated the Simon effect behaviorally.
• A significant difference in P300 amplitude was observed in the low-risk group under high load.
• Prime congruence effects were significant in the low load condition for both groups, with N200 reflecting attentional processes.

Conclusions:

• Differential neural responses in high-risk AD participants suggest potential early cognitive impairment.
• Attentional load influences neural processing differently between high-risk and low-risk individuals.
• ERP findings indicate distinct attentional processing mechanisms in preclinical AD stages.