Types of errors on a semantic interference task in mild cognitive impairment and dementia

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Subtle cognitive impairment often precedes dementia diagnosis.
• Early detection of cognitive decline is crucial for timely intervention.
• Verbal memory tasks can reveal early signs of neurodegeneration.

Purpose of the Study:

• To evaluate the utility of qualitative analysis of intrusion errors in detecting preclinical cognitive impairment.
• To identify specific types of semantic intrusions indicative of early-stage dementia.
• To assess the sensitivity of the Loewenstein-Acevedo Scales of Semantic Interference and Learning (LASSI-L) in identifying early cognitive changes.

Main Methods:

• 160 participants (cognitively normal, mild cognitive impairment, dementia) were assessed using the LASSI-L.
• Semantic intrusion errors were qualitatively analyzed across diagnostic groups.
• The sample included diverse ethnic backgrounds (Hispanics and European Americans).

Main Results:

• Competing list intrusions (CLI) and semantically related intrusions (SRI) were the most common error types.
• CLI and SRI significantly differentiated between cognitively normal and mild cognitive impairment groups.
• These intrusion errors correlated with brain amyloid load, suggesting a link to Alzheimer's-related neurodegeneration.
• No significant ethnicity effects were observed in intrusion error types.

Conclusions:

• Specific intrusion errors (CLI and SRI) are more prevalent in individuals with mild cognitive impairment compared to cognitively normal individuals.
• The LASSI-L demonstrates sensitivity in detecting cognitive changes at the earliest stages of aging.
• Qualitative analysis of intrusion errors shows promise as a biomarker for preclinical dementia.