title: Efficiency of Attentional Components in Elderly with Mild Neurocognitive Disorders Shown by the Attention Network Test.
abstract: OBJECTIVE
  Complex attention, serving as a main diagnostic item of mild neurocognitive disorders (NCD), has been reported to be susceptible to pathological ageing. This study aimed to evaluate the attention network functions in older adults with subtypes of NCD.
  
  
  METHODS
  36 adults with NCD due to Alzheimer's disease (NCD-AD), 31 adults with NCD due to vascular disease (NCD-vascular) and 137 healthy controls were recruited. Attention Network Test (ANT) was conducted to assess the efficiency of alerting, orienting and executive control.
  
  
  RESULTS
  Significant between-group differences were found in executive control (conventional score: F = 11.472, p < 0.001; ratio score: F = 8.430, p < 0.001) and processing speed (F = 4.958, p = 0.008). NCD subgroups demonstrated poorer performance on the ANT, particularly on executive control (healthy 59.9 ± 45.9, NCD-vascular 88.9 ± 44.8, NCD-AD 97.0 ± 53.9). Moreover, the NCD-AD group showed both less efficient executive control and prominent slowing processing speed (reaction time: healthy 687.5 ± 106.0 ms, NCD-vascular 685.3 ± 97.1 ms, NCD-AD 750.6 ± 132.6 ms).
  
  
  CONCLUSIONS
  The NCD-vascular group appeared to be less efficient in executive control, while the NCD-AD group demonstrated less effective executive control and also slower processing speed. These results suggest that the characterized performance of ANT, processing speed and executive control in particular, might help differentiate adults at risk of different forms of cognitive impairment.
authors.affiliation: Department of Psychiatry, The Chinese University of Hong Kong, G/F, Multi-Centre, Tai Po Hospital, Hong Kong, SAR, China.
authors.forename: Hanna
authors.initials: H
authors.lastname: Lu
authors.forename: Sandra S M
authors.initials: SS
authors.lastname: Chan
authors.forename: Ada W T
authors.initials: AW
authors.lastname: Fung
authors.forename: Linda C W
authors.initials: LC
authors.lastname: Lam
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D000544:Alzheimer Disease / Q000175:diagnosis; D001288:Attention; D060825:Cognitive Dysfunction / Q000175:diagnosis*; D018450:Disease Progression; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*