Table 1

Summary of main findings per condition and domain

ParameterFunctional cognitive disorder***FibromyalgiaChronic fatigue syndromeFunctional neurological disorder†
Cognitive symptomsMemory
Language (word finding)		Attention/concentration
Memory
Language (word finding)		Attention/concentration
Memory
Language (word finding)
Reasoning		Attention/concentration
Memory
Language (word finding)
Objective neuropsychological deficits
MemoryVulnerability to distraction
Explicit worse than implicit memory*		Impaired registration and consolidation*
Working memory disruption by abnormal attention/information processing*		Working memory**
Attention/concentrationSelective/divided attention*
Bias towards emotionally negative information**		Divided attention
Executive function of attention**
Bias towards threatening stimuli*		Attention**
Attentional bias towards social threatening stimuli**
Executive functionsCognitive inhibition**
Information processingSlowSlow**
LanguageVerbal fluency*Verbal fluency**
Social cognitionAlexithymia**
Recognising others’ emotions*		Alexithymia*
Affect expression and recognition**
Consistency on repeat assessmentIncreased performance variability
Factors related with neuropsychological deficitsPain*Fatigue**Psychopathology**
Discrepancies between symptoms and objective deficitsSymptoms>objective deficitsSymptoms>objective deficitsSymptoms>objective deficitsSymptoms>objective deficits**
Performance validity/effort testingA minority fail validity testingOnly a minority fail validity testing*Rare failures on validity testing*Overall, only a minority fail validity testing
Neurobiology of cognitive impairmentNo structural damageNo structural damage*
Dysfunction of a fronto-parieto-temporal network involved in attention, memory and executive functions, as well in emotion and pain processing		No structural damage*
Dysfunction of the working memory network		No structural damage
OthersMemory perfectionism
Overinterpretation of attentional lapses
Heightened self-monitoring for cognitive errors
Low memory self-efficacy		Heightened perception of effort

  • *, some evidence but inconsistent between studies; **, some evidence but particularly inconsistent and/or scarce; ***Proposed features.

  • †Non-epileptic attacks and functional movement disorders.