Reaction Time Decomposition as a Tool to Study Subcortical Ischemic Vascular Cognitive Impairment

Area of Science:

• Cognitive Neuroscience
• Neuropsychology
• Gerontology

Background:

• Reaction time (RT) and intraindividual variability (IIV) studies in aging and dementia often overlook specific processing stages.
• Mental chronometry techniques allow for the analysis of distinct processing components in cognitive tasks.

Purpose of the Study:

• To investigate if RT and IIV-decomposition can reveal deficits in subcortical ischemic vascular cognitive impairment (VCI).
• To determine if VCI affects both response initiation and movement phases, and if these effects are reflected in both RT and IIV using a novel iPad task.

Main Methods:

• Touch cancellation RT and IIV were measured using an iPad task.
• Participants included younger adults, cognitively healthy older adults, and patients with VCI.

Main Results:

• Cognitively healthy aging slowed RT but did not increase IIV in response initiation or movement.
• Vascular cognitive impairment (VCI) led to slower RT and increased IIV in both response phases.
• Significant group differences emerged concerning response phase characteristics.

Conclusions:

• Intraindividual variability (IIV) is a more sensitive indicator than absolute RT for distinguishing VCI from normal aging.
• VCI is associated with deficits in both action planning/initiation and movement execution, more so than in healthy aging.
• These findings have implications for real-world activities, including driving safety, employment, and fall risk.