Stroop task and practice effects demonstrate cognitive dysfunction in long COVID and myalgic encephalomyelitis / chronic fatigue syndrome. — CFSMEATLAS
Stroop task and practice effects demonstrate cognitive dysfunction in long COVID and myalgic encephalomyelitis / chronic fatigue syndrome.
Baraniuk, James N, Thapaliya, Kiran, Inderyas, Maira et al. · Scientific reports · 2024 · DOI
Quick Summary
This study tested how quickly people with Long COVID and ME/CFS could complete a simple task involving reading color words displayed in different colored inks. Both patient groups were noticeably slower at this task than healthy people, and unlike healthy people, they didn't get faster with practice. This suggests that ME/CFS and Long COVID may involve a problem with how different parts of the brain communicate during problem-solving.
Why It Matters
This study provides objective, quantifiable evidence of cognitive dysfunction in ME/CFS and Long COVID, moving beyond subjective patient reports to measurable neuropsychological deficits. Understanding that cognitive impairment persists despite practice suggests a fundamental communication problem in the brain rather than simple attention or fatigue issues, which could guide future treatment development. The similarities between LC and ME/CFS cognitive profiles may identify shared pathophysiological mechanisms.
Observed Findings
Long COVID and ME/CFS patients showed significantly longer response times on the Stroop task compared to healthy controls
Initial response times ranked Long COVID > ME/CFS > healthy controls, but converged by the end of the task
Cognitive slowing persisted despite practice, unlike the improvement seen in healthy controls
Response times were slower when stimuli followed incongruent prestimuli, suggesting interference effects
Patterns of cognitive resource recruitment were similar across all three groups despite different absolute performance levels
Inferred Conclusions
Global slowing of cognitive processing occurs in both Long COVID and ME/CFS and cannot be overcome by practice or habituation
Cognitive dysfunction likely reflects impaired communication between brain network nodes during problem-solving
Long COVID and ME/CFS appear to share similar cognitive dysfunction mechanisms
The cognitive slowing is not due to inability to learn or adapt, but to a fundamental processing speed limitation
Remaining Questions
What specific brain networks or communication pathways are impaired in Long COVID and ME/CFS?
What This Study Does Not Prove
This study demonstrates cognitive slowing but does not identify which specific brain regions or networks are responsible for the impairment. It cannot distinguish whether the problem originates from reduced overall brain communication capacity, metabolic limitations, or other physiological factors. The findings are correlational and do not establish causation or explain why this cognitive dysfunction occurs.