title: Cognitive decline and slower reaction time in elderly individuals with mild cognitive impairment.
abstract: OBJECTIVE
  The relationship between declining performance, as measured by changes in reaction time, and declining cognitive function has not been critically studied. The aim of the present study was to investigate the association between reaction time during a task and cognitive ability in elderly Taiwanese individuals.
  
  
  METHODS
  Patients aged 65 years or older with mild cognitive impairment (MCI) (n = 33) and Alzheimer's disease (n = 26) were recruited from the neurology clinic of a regional hospital in southern Taiwan. In addition, 28 healthy controls aged 65 years or older were recruited from the community. The cognitive performance of the study participants was assessed using the Cognitive Abilities Screening Instrument (CASI). A computer-administered simple reaction time (SRT) task and a flanker reaction time (FRT) task were administered to assess participants' cognitive function. A non-parametric Kruskal-Wallis test was performed to compare CASI scores, SRT, and FRT among the three groups. anova was also used to compare CASI scores, inverse-transformed SRT, and inverse-transformed FRT among the three groups, with adjustment for age and years of education. Additionally, Pearson's partial correlation coefficients were used to assess the association of CASI scores with inverse-transformed SRT, and inverse-transformed FRT within each of the three groups.
  
  
  RESULTS
  Significant differences in CASI scores, SRT, and FRT were found between the Alzheimer's disease group and the other two groups, either with or without adjustment for age or education. The reaction time of patients with Alzheimer's disease was significantly slower than the other two groups. Moreover, significant correlation between CASI and FRT was found in patients with MCI.
  
  
  CONCLUSIONS
  Altered performance in a speed task was observed in patients with MCI. The FRT task should further be explored for its role as a marker for cognitive decline in elderly individuals, particularly in those with MCI.
authors.affiliation: Department of Psychology, National Chung Cheng University, Chiayi, Taiwan.|Clinical Psychology Center, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
authors.forename: Ko-Chia
authors.initials: KC
authors.lastname: Chen
authors.affiliation: Department of Psychology, National Chung Cheng University, Chiayi, Taiwan.
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Weng
authors.affiliation: Department of Psychology, National Chung Cheng University, Chiayi, Taiwan.
authors.forename: Sigmund
authors.initials: S
authors.lastname: Hsiao
authors.affiliation: Division of Neurology, Department of Internal Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.|Dementia Center, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
authors.forename: Wen-Long
authors.initials: WL
authors.lastname: Tsao
authors.affiliation: Department of Medical Research, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.|Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Koo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D009048:Motor Skills; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology*; D013624:Taiwan; D013647:Task Performance and Analysis
keywords: 
  Alzheimer’s disease; cognitive function; mild cognitive impairment; psychological techniques; reaction time