Stroop task and practice effects demonstrate cognitive dysfunction in Long COVID and ME/CFS, 2024, Baraniuk et al

Now published: link here

Preprint
Background. The Stroop task was used to investigate differences in cognitive function between Long COVID (LC), Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS) and healthy control subjects.

Methods. Subjects viewed four color words or neutral (XXXX) stimuli with the same (congruent) or different color ink (incongruent). Cognitive conflict was inferred from response times for pairings of prestimuli and subsequent stimuli. Overall effects were assessed by univariate analysis with time courses determined for binned response times.

Results. LC and ME/CFS had significantly longer response times than controls indicating cognitive dysfunction. Initial response times were ranked LC>ME>HC, and decreased according to power functions. At the end of the task (900s), times were ranked LC=ME>HC. Response times were significantly slower for stimuli following an incongruent prestimulus. Time series for Stroop effect, facilitation, interference, surprise index and practice power law parameters were generally similar in LC, ME/CFS and HC suggesting comparable patterns for recruitment of cognitive resources. The prestimulus data were analyzed and generated positive Stroop and interference effects that were distinct from stimulus effects.

Conclusion. LC and ME/CFS have global slowing of response times that cannot be overcome by practice suggesting slower neurotransmission or white matter conduction between network nodes during problem solving. Analysis of matched prestimulus – stimulus effects adds a new dimension for understanding cognitive conflict.

Brief Summary. Cognitive dysfunction in Long COVID and ME/CFS was demonstrated using the Stroop task which found global slowing of response times and limitations of practice effects.

Link | PDF

 

Those with ME met either the ICC or Fukuda.
Even though the abstract says "PEM is the key manifestation..." the article does not indicate that PEM was required of those selected.
It would be interesting to know who the adjudicator was who verified diagnosis...

 

This "cognitive conflict" reference is unsettling.

 

I haven’t read where it is but will note this:

stroop involves having the word red presented in the colour green

you are then battling to focus on what the word reads as rather than the colour it is written in

like a sort of Pat your head rub your tummy

so it might be relating to those conflicting messages where the colour it’s in is different to the colour it’s spelling

 

Thanks for the explanation. I thought it might be something along those lines when I read the discussion. Still seemed needlessly psychological when trying to infer organic brain problems.

It warrants a slower and more deliberate read-through, if only for the historical Wallit ties.

 

Yes I understand I will too if I can

they could have the term mismatch or contradicting messages

I’m not in a position to say I’m on top of all the lingo in all areas of psych these days vs previous years but there is always choice in terms used so somewhere I suspect there’s not necessarily a known goal but a nudge or choice to certain ideology if someone has that option and thinks a certain way


These types of test are interesting because they have a big drain on executive function / you need a certain level otherwise you start failing at it and the effort shows in time lags EDiT: now I could have used a different term there (as its complexity of task in truth) but I wonder if my Freudian slip has shown up why they might be ‘into’ this?

it’s also like having a convo where we can be in automatic vs direct complex questions - as when the colour and word are congruent it can use autopilot a bit.

of course few ever factor in or even describe in limitations what else pwme or any other conditions might be battling with such as pain from various places or trying to slump in their chair to manage OI symptoms as they feel them coming on - plus we all learn to do that not sub consciously but without overtly thinking of it like you would if driving and pulled down the visor when the sun dazzles etc

I suspect these are useful put have the same risks and potential for interpretation saying tiredness vs threshold. Plus they would be most useful as within-person comparators because there will be individual differences anyway

ie as a test in the days after eg a long day at work to see when the sfter-effect of that work day lifts.

Or the impact of sound on pwme vs no pwme either before or during (to see if each pwme has a performance that drops compared to when there was no background sound)

ie more helpful for us if people are trying to show the illness ie PEM and these are symptoms

a real problem if someone is trying to suggest instead of having a threshold on energy and overload someone might twist it to something a therapy would tackle or something

 

Is there an accompanying colour blindness test?

 

or they'd just use a pair of colours that aren't confused in colour blindness? Last time I did a Stroop test it was red and blue.

 

Now published (Nature Scientific Reports, 5 November 2024):

Link | PDF

 

New title and published abstract.

Stroop task and practice effects demonstrate cognitive dysfunction in long COVID and myalgic encephalomyelitis / chronic fatigue syndrome

Abstract

Background: The Stroop task was used to investigate differences in cognitive function between Long COVID (LC), Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS) and healthy control subjects.

Methods: Subjects viewed four color words or neutral (XXXX) stimuli with the same (congruent) or different color ink (incongruent). Cognitive conflict was inferred from response times for pairings of prestimuli and subsequent stimuli. Overall effects were assessed by univariate analysis with time courses determined for binned response times.

Results: LC and ME/CFS had significantly longer response times than controls indicating cognitive dysfunction. Initial response times were ranked LC > ME > HC, and decreased according to power functions. At the end of the task (900s), times were ranked LC = ME > HC. Response times were significantly slower for stimuli following an incongruent prestimulus. Time series for Stroop effect, facilitation, interference, surprise index and practice power law parameters were generally similar in LC, ME/CFS and HC suggesting comparable patterns for recruitment of cognitive resources. The prestimulus data were analyzed and generated positive Stroop and interference effects that were distinct from stimulus effects.

Conclusion: LC and ME/CFS have global slowing of response times that cannot be overcome by practice suggesting impaired communications between network nodes during problem solving. Analysis of matched prestimulus – stimulus effects adds a new dimension for understanding cognitive conflict. Brief Summary: Cognitive dysfunction in Long COVID and ME/CFS was demonstrated using the Stroop task which found global slowing of response times and limitations of practice effects.