| Literature DB >> 26878035 |
Adriana Seelye1, Stuart Hagler2, Nora Mattek1, Diane B Howieson3, Katherine Wild1, Hiroko H Dodge1, Jeffrey A Kaye4.
Abstract
INTRODUCTION: Subtle changes in cognitively demanding activities occur in MCI but are difficult to assess with conventional methods. In an exploratory study, we examined whether patterns of computer mouse movements obtained from routine home computer use discriminated between older adults with and without MCI.Entities:
Keywords: aging; cognitive assessment; computer use; early detection of cognitive decline; ecological validity; everyday functioning; functional assessment; instrumental activities of daily living (IADLs); mild cognitive impairment; remote monitoring; technology
Year: 2015 PMID: 26878035 PMCID: PMC4748737 DOI: 10.1016/j.dadm.2015.09.006
Source DB: PubMed Journal: Alzheimers Dement (Amst)
Criteria for MCI classification
Objective evidence of impairment on at least two neuropsychological tests within one or more of six cognitive domains, with scores falling at least one standard deviation or more below the mean values stratified by age based on available normative data Nonfulfillment of criteria for dementia Preserved general cognitive functions as confirmed by a score of ≥24 on the MMSE No significant impact on functional abilities, as confirmed by two or fewer activities marked as dependent on the FAQ Absence of severe depression as confirmed by a score <5 on the 15-item GDS. |
Abbreviations: MCI, mild cognitive impairment; MMSE, mini-mental state examination; FAQ, functional activities questionnaire; GDS, geriatric depression scale.
NOTE. Diagnosis of MCI was consistent with the criteria defined by Jak et al. [29] and with the criteria outlined by the National Institute on Aging-Alzheimer's Association workgroup [30].
Neuropsychological tests used for MCI classification
| Cognitive domain | Neuropsychological tests |
|---|---|
| Memory | WMS-R Logical Memory II Story A |
| Language | Boston Naming Test |
| Executive function | Letter fluency (CFL) |
| Processing speed | WAIS-R Digit Symbol |
| Working memory | WAIS-R Digits Backward |
| Visual perception/Construction | WAIS-R Block Design |
Abbreviations: MCI, mild cognitive impairment; WMS-R, Wechsler memory scale-revised; CERAD, consortium to establish a registry for Alzheimer's disease; WAIS-R, Wechsler adult intelligence scale-revised; WAIS-III, Wechsler adult intelligence scale-third edition; MMSE, mini-mental state examination.
Fig. 1Graphical representation of a mouse movement.
Demographics and mouse movement variables
| Demographics and variables | Cognitively intact, mean (SD), n = 42 | MCI, mean (SD), n = 20 |
|---|---|---|
| Age (y) | 87.9 (5.2) | 87.5 (6.6) |
| Gender (% Women) | 88 | 80 |
| Education (y) | 15.6 (2.5) | 13.5 (2.9)** |
| Any depressed (down/blue) mood (% past month from weekly health survey) | 5 | 5 |
| MMSE | 28.8 (1.2) | 27.3 (1.4)** |
| CIRS | 20.0 (2.1) | 20.6 (2.6) |
| Median delta | 50.6 (23.0) | 36.5 (14.6)* |
| IQR delta | 138.2 (50.5) | 112.0 (50.4) |
| Median D | 56.5 (24.6) | 42.3 (19.3)* |
| IQR D | 150.5 (54.7) | 123.7 (55.9) |
| Median T | 237.2 (72.2) | 199.9 (55.5)* |
| IQR T | 332.6 (122.2) | 325.7 (143.7) |
| Median K | 0.88 (0.02) | 0.87 (0.03) |
| IQR K | 0.14 (0.02) | 0.15 (0.02)* |
| Median idle | 308.7 (61.4) | 346.6 (104.6) |
| IQR idle | 832.0 (424.6) | 1249.9 (942.6)* |
| Number of mouse movements contributed | 7871 (9679) | 1497 (1684)** |
| Number of computer sessions contributed | 9.5 (11.2) | 4.9 (4.2) |
Abbreviations: SD, standard deviation; MCI, mild cognitive impairment; MMSE, mini-mental state examination; CIRS, cumulative illness rating scale; Delta, straight-line distance traveled by the mouse, between starting and end points, in counts; IQR, interquartile range; D, total distance traveled by the mouse in counts; T, time taken to make a mouse movement in milliseconds; K, mouse movement curvature, ranging from 0 to 1 (0 = looped, 1 = straight line); idle, time spent idling or pausing between successive mouse movements in milliseconds.
NOTE. *P < .05; **P < .01.
Fig. 2Mouse movement variables by cognitive status. Mouse position data were recorded using the computer's internal representation of the mouse position in counts, thus mouse movements are characterized as changes in position with distances measured in counts. Abbreviations: IQR, interquartile range; MCI, mild cognitive impairment.
Associations between cognitive status and mouse movement variability derived from one week of data
| Covariate | Outcome, movement curvature (IQR_K) | Outcome, time spent idling (IQR_Idle) | ||
|---|---|---|---|---|
| Coefficient | Coefficient | |||
| MCI (reference: cognitively intact group) | 0.013 | .008** | 386.8 | .04* |
| Age (y) | −0.001 | .03* | −15.0 | .31 |
| Education (y) | 0.002 | .05 | −12.4 | .70 |
Abbreviations: IQR, interquartile range; MCI, mild cognitive impairment.
NOTE. *P < .05, **P < .01.
Spearman's ρ-positive correlations between mouse movement variables and cognitive domain z-scores among 62 older adults
| Computer use measures | Cognitive domains | |||||
|---|---|---|---|---|---|---|
| Global cognition | Executive functioning | Working memory | Attention | Memory | Visual spatial | |
| Median delta | NS | NS | ||||
| IQR delta | NS | NS | NS | |||
| Median D | NS | NS | ||||
| IQR D | NS | NS | ||||
| Median T | NS | NS | ||||
| IQR T | NS | NS | NS | NS | NS | |
| Median K | NS | NS | NS | NS | NS | |
| IQR K | NS | NS | NS | NS | NS | NS |
| Median idle | NS | NS | NS | NS | NS | NS |
| IQR idle | NS | NS | NS | NS | NS | NS |
Abbreviations: NS, correlations that were not statistically significant; IQR, interquartile range; delta, straight-line distance traveled by the mouse, between starting and end points, in counts; D, total distance traveled by the mouse in counts; T, time taken to make a mouse movement in milliseconds; K, mouse movement curvature, ranging from 0 to 1 (0 = looped, 1 = straight line); idle, time spent idling or pausing between successive mouse movements in milliseconds.
NOTE. Individual participant neuropsychological test scores were z-normalized, summed, and averaged for each cognitive domain. Cognitive domain z-scores were tabulated from 2 to 3 representative neuropsychological tests for each domain.
Fig. 3Scatterplot displaying median time taken to make a mouse movement in milliseconds (T) by global cognitive z-score among 62 older adults. Cognitive domain z-scores were calculated using group mean and standard deviations of the raw test scores from all cognitively intact subjects (CDR = 0) at study entry into the ORCATECH cohort (n = 180). Global cognition z-scores were tabulated from cognitive tests in the domains of working memory, attention and processing speed, memory, executive function, and visual perception/construction. Abbreviations: CDR, clinical dementia rating.