Cognitive Correlates of Digital Clock Drawing Metrics in Older Adults with and without Mild Cognitive Impairment

Abstract

Background-A digital version of the clock drawing test (dCDT) provides new latency and graphomotor behavioral measurements. These variables have yet to be validated with external neuropsychological domains in non-demented adults.Objective-The current investigation reports on cognitive constructs associated with selected dCDT latency and graphomotor variables and compares performances between individuals with mild cognitive impairment (MCI) and non-MCI peers.Methods-202 non-demented older adults (age 68.79 ± 6.18, 46% female, education years 16.02 ± 2.70) completed the dCDT and a comprehensive neuropsychological protocol. dCDT variables of interest included: total completion time (TCT), pre-first hand latency (PFHL), post-clock face latency (PCFL), and clock face area (CFA). We also explored variables of percent time drawing (i.e., 'ink time') versus percent time not drawing (i.e., 'think time'). Neuropsychological domains of interest included processing speed, working memory, language, and declarative memory.Results-Adjusting for age and premorbid cognitive reserve metrics, command TCT positively correlated with multiple cognitive domains; PFHL and PCFL negatively associated with worse performance on working memory and processing speed tests. For Copy, TCT, PCFL, and PFHL negatively correlated with processing speed, and CFA negatively correlated with language. Between-group analyses show MCI participants generated slower command TCT, produced smaller CFA, and required more command 'think' (%Think) than 'ink' (%Ink) time.

Proof of concept: digital clock drawing behaviors prior to transcatheter aortic valve replacement may predict length of hospital stay and cost of care

“…At this time, it is unclear why CDT variables of interest in the command condition did not predict hospital outcomes. Total clock drawing time to command, for example, associates with numerous cognitive domains [16]. Given the many cognitive domains involved in drawing a clock to command, it may be that the command condition can identify impairment in any cognitive domain, while individuals who show The graphomotor variables of hour hand distance from center and ideal digit placement difference are, theoretically, more sensitive to neurodegenerative changes within the dorsal attentional stream, as with aging there is atrophy of the dorsal stream which may lead to an upward attentional bias [31,32].…”

“…One potential tool is the digitally-acquired clock drawing test (CDT), where patients are first asked to draw a clock to a command and then copy a model of a clock [15][16][17][18][19]. The CDT is a classic neuropsychological tool often used as a cognitive screener for dementia [20,21].…”

Paradigm Shift Toward Digital Neuropsychology and High-Dimensional Neuropsychological Assessments: Review

“…Digital pens have a spatial resolution of ±0.002 inches. For example, digital pens are being used by neuropsychologists for assessing clock drawing performance [ 68 , 69 ]. Minute drawing elements such as pen strokes (eg, clock face, hand, digit) can be logged with greater than 84% accuracy [ 70 ].…”

Diagnostic accuracy of early cognitive indicators in mild cognitive impairment

“…16 However, there is substantially less research that evaluates deficits in PS in MCI. [32][33][34] Likewise, recent studies highlight the cognitive heterogeneity in AD, showing the importance of studying other cognitive aspects in addition to episodic memory. [35][36][37][38] Normal aging and some psychiatric disorders (such as MCI and AD) were associated with decline in PS.…”

“… 16 However, there is substantially less research that evaluates deficits in PS in MCI. 32 – 34 Likewise, recent studies highlight the cognitive heterogeneity in AD, showing the importance of studying other cognitive aspects in addition to episodic memory. 35 – 38 …”