Attentional control in amnestic MCI subtypes: insights from a Simon task

Area of Science:

• Cognitive Neuroscience
• Neuropsychology
• Aging Research

Background:

• Attentional control is crucial for cognitive function, especially in aging.
• Mild cognitive impairment (MCI) presents heterogeneous subtypes, impacting cognitive domains differently.
• Understanding executive function deficits in amnestic MCI (aMCI) subtypes is vital for early intervention.

Purpose of the Study:

• To compare attentional control abilities between healthy controls (HC) and subtypes of aMCI.
• To investigate group differences in dynamic performance changes across the reaction time (RT) distribution.
• To analyze the impact of automatic vs. deliberate response pathways in different cognitive groups.

Main Methods:

• A spatial stimulus-response consistency task was administered to 31 multiple domain MCI (md-MCI), 31 single domain MCI (sd-MCI), and 41 HC participants.
• Reaction times (RTs), number of errors (NEs), and omitted responses (ORs) were analyzed.
• Statistical methods controlled for age and processing speed effects to isolate attentional control differences.

Main Results:

• No significant group differences in RTs were observed across consistency conditions.
• The md-MCI group showed lower accuracy (more NEs) than HC on inconsistent trials.
• Distributional analyses revealed similar RT-Simon and NE-Simon effects across groups, but a greater NE-Simon effect in md-MCI for faster RTs.

Conclusions:

• All groups struggled with suppressing automatic responses and engaging deliberate control.
• The md-MCI group demonstrated a quantitatively greater impairment, characterized by stronger automatic response pathway activation.
• Findings suggest specific executive function challenges in md-MCI related to response inhibition.