title: Learning Classification Models of Cognitive Conditions from Subtle Behaviors in the Digital Clock Drawing Test.
abstract: The Clock Drawing Test - a simple pencil and paper test - has been used for more than 50 years as a screening tool to differentiate normal individuals from those with cognitive impairment, and has proven useful in helping to diagnose cognitive dysfunction associated with neurological disorders such as Alzheimer's disease, Parkinson's disease, and other dementias and conditions. We have been administering the test using a digitizing ballpoint pen that reports its position with considerable spatial and temporal precision, making available far more detailed data about the subject's performance. Using pen stroke data from these drawings categorized by our software, we designed and computed a large collection of features, then explored the tradeoffs in performance and interpretability in classifiers built using a number of different subsets of these features and a variety of different machine learning techniques. We used traditional machine learning methods to build prediction models that achieve high accuracy. We operationalized widely used manual scoring systems so that we could use them as benchmarks for our models. We worked with clinicians to define guidelines for model interpretability, and constructed sparse linear models and rule lists designed to be as easy to use as scoring systems currently used by clinicians, but more accurate. While our models will require additional testing for validation, they offer the possibility of substantial improvement in detecting cognitive impairment earlier than currently possible, a development with considerable potential impact in practice.
authors.affiliation: MIT Computer Science And Artificial Intelligence Laboratory, Tel.: +1-617-800-3033, souillardmandar@csail.mit.edu.
authors.forename: William
authors.initials: W
authors.lastname: Souillard-Mandar
authors.affiliation: MIT Computer Science And Artificial Intelligence Laboratory, Tel.: +1-617-253-5879, davis@csail.mit.edu.
authors.forename: Randall
authors.initials: R
authors.lastname: Davis
authors.affiliation: MIT Computer Science And Artificial Intelligence Laboratory, rudin@mit.edu.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Rudin
authors.affiliation: Boston University School of Medicine, rhodaau@bu.edu.
authors.forename: Rhoda
authors.initials: R
authors.lastname: Au
authors.affiliation: Drexel Neuroscience Institute, Drexel University College of Medicine, dlibon@drexelmed.edu.
authors.forename: David J
authors.initials: DJ
authors.lastname: Libon
authors.affiliation: University of North Dakota Medical School, rod@neuropsychnd.com.
authors.forename: Rodney
authors.initials: R
authors.lastname: Swenson
authors.affiliation: University of Florida, Gainesville, cep23@phhp.ufl.edu.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Price
authors.affiliation: University of Illinois, Chicago, mlamar@psych.uic.edu.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lamar
authors.affiliation: Lahey Health, Burlington, Massachusetts, dana.l.penney@lahey.org.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Penney
keywords: Clock Drawing Test; Cognitive Impairment Diagnostics; Interpretable Machine Learning; Machine Learning Applications; Medical Scoring Systems