title: Association of retrospective time estimation and severity of cognitive impairment.
abstract: Time perception has an important role in everyday life, but is not commonly measured in clinical routine assessment of suspected cognitive impairment, given the complexity of available assessment methods. Furthermore, evidence on the pattern of retrospective time perception in neurodegenerative diseases is contradictory.
  
  
  
  We asked 321 patients referred to neuropsychological assessment to retrospectively estimate the duration of the neuropsychological assessment session. We calculated the session actual duration, ratio, and accuracy of response. Patients were grouped into three categories: subjective cognitive impairment, mild cognitive impairment, and mild to moderate dementia.
  
  
  
  We found an overall tendency for underestimation of time, but no significant differences between groups regarding time estimation. There were significant, but weak, associations between time estimation and severity of cognitive impairment in several domains, with slightly different patterns across groups.
  
  
  
  Regardless of etiology, the majority of patients underestimated time, which was weakly associated with the severity of cognitive impairment. Global retrospective estimation may be clinically informative, particularly in a minority of extreme cases.
authors.affiliation: a Neurocognition Unit, Neurology Department, Hospital de Braga , Braga , Portugal.
authors.forename: Ana Sofia
authors.initials: AS
authors.lastname: Costa
authors.affiliation: a Neurocognition Unit, Neurology Department, Hospital de Braga , Braga , Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Rocha
authors.affiliation: a Neurocognition Unit, Neurology Department, Hospital de Braga , Braga , Portugal.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Machado
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000523:psychology; D003704:Dementia / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012189:Retrospective Studies; D013998:Time Perception / Q000502:physiology*
keywords: Cognitive impairment; Dementia; Mild cognitive impairment; Retrospective time estimation; Time perception