Time setting errors in the Clock Drawing Test are associated with both semantic and executive deficits

Abstract

The common requirement to set the time to “10 past 11” on the Clock Drawing Test is intended to elicit a stimulus bound response (SBR), in which the responder is “pulled” to the salient stimulus “10,” resulting in hands set at “10 before 11.” SBRs are considered markers of executive dysfunction, although this assumption has not yet been validated. We compared SBR and other time-setting errors on inhibitory control tests, hypothesizing that they represent related constructs. The role of semantic dysfunction in the formation of those errors was also investigated. We examined baseline test performance of participants with Mild Cognitive Impairment or a history of depression, and control participants, enrolled in a dementia prevention study. Among 258 participants, we identified clocks with SBRs (n = 16), other time errors (n = 22), or no errors at all (n = 42). Performance between the groups with SBRs and other time-setting errors did not differ on any of the executive tests, and both error groups performed significantly worse than the No Error group on the semantic tests. Control for covariates further supported semantic and executive components in time-setting errors. Both semantic and inhibitory control deficits may underlie time representation errors in general.

Keywords:

• Clock Drawing Test
• depression
• executive function
• mild cognitive impairment
• qualitative analysis
• semantic function

Acknowledgments

The authors thank Marcos Sanches for his statistical support. The PACt-MD Study Group comprises: Benoit H. Mulsant, Tarek K. Rajji, Nathan Herrmann, Bruce G. Pollock, Lillian Lourenco, Daniel M. Blumberger, Christopher R. Bowie, Meryl Butters, Corinne Fischer, Alastair Flint, Damian Gallagher, Angela Golas, Ariel Graff, James L. Kennedy, Sanjeev Kumar, Krista Lanctôt, Linda Mah, Shima Ovaysikia, Mark Rapoport, Kevin Thorpe, Nicolaas P.L.G. Verhoeff, Aristotle N. Voineskos.

Disclosure statement

CRB has received in-kind research accounts from Scientific Brain Training Pro. CEF has grant funding from the following industry partners: Vielight Inc, Hoffman La Roche. AJF has received grant support from the U.S. National Institutes of Health, the Patient-Centered Outcomes Research Institute, the Canadian Institutes of Health Research, Brain Canada, the Ontario Brain Institute, Alzheimer’s Association, and AGE-WELL. SK has received research support from Brain and Behavior Foundation, National institute on Aging, BrightFocus Foundation, Brain Canada, Canadian Institute of Health Research, Canadian Consortium on Neurodegeneration in Aging, Center for Aging and Brain Health Innovation, Center for Addiction and Mental Health, and an Academic Scholars Award from the Department of Psychiatry, University of Toronto. SK receives equipment support from Soterix Medical. KLL reports grants from Alzheimer’s Association, Alzheimer Society of Canada, Alzheimer’s Drug Discovery Foundation, Canadian Institutes of Health Research, National Institute on Aging; consulting fees from Abide, BioXcel, Cerevel, Exciva, Highmark Interactive, ICG Pharma, Kondor Pharma, and Otsuka. BHM holds the Labatt Family Chair in Biology of Depression in Late-Life Adults at the University of Toronto. He currently receives research support from Brain Canada, the Canadian Institutes of Health Research, the CAMH Foundation, the Patient-Centered Outcomes Research Institute (PCORI), the US National Institute of Health (NIH), Capital Solution Design LLC (software used in a study founded by CAMH Foundation), and HAPPYneuron (software used in a study founded by Brain Canada). He has been an unpaid consultant to Myriad Neuroscience. He directly owns stocks of General Electric (less than $5,000). BGP has received research support from the Peter & Shelagh Godsoe Endowed Chair in Late-Life Mental Health, CAMH Foundation and Discovery Fund, National Institute of Aging, Brain Canada, the Canadian Institutes of Health Research, the Alzheimer’s Drug Discovery Foundation, the Ontario Brain Institute, the Center for Aging and Brain Health Innovation, the Bright Focus Foundation, the Alzheimer’s Society of Canada, the W. Garfield Weston Foundation, the Weston Brain Institute, the Canadian Consortium on Neurodegeneration in Aging and Genome Canada. Honoraria from the American Geriatrics Society. He holds United States Provisional Patent No.62/466,651 for a cell-based assay and kits for assessing serum anticholinergic activity. TKR has received research support from Brain Canada, Brain and Behavior Research Foundation, BrightFocus Foundation, Canada Foundation for Innovation, Canada Research Chair, Canadian Institutes of Health Research, Center for Aging and Brain Health Innovation, National Institutes of Health, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research and Innovation, and the Weston Brain Institute. TKR also received in-kind equipment support for an investigator-initiated study from Magstim, and in-kind research accounts from Scientific Brain Training Pro. The research funding of MAB is supported by the US National Institutes of Health. All other Authors report no potential conflict of interest.

Additional information

Funding

This work was supported by Brain Canada through the Canada Brain Research Fund, with the financial support of Health Canada and the Chagnon Family; and the Labatt Family Chair in the Biology of Depression in Late-Life Adults at the University of Toronto.