Date of Award


Degree Name

Doctor of Philosophy


Interdisciplinary Health Sciences

First Advisor

Dr. Kieran Fogarty

Second Advisor

Dr. Rob Lyerla

Third Advisor

Dr. Suma Devanga

Fourth Advisor

Dr. Jeffrey Fletcher


Clock drawing test, cognition, cognitive screening, young adults, speech-language pathology, cognitive assessment


The clock drawing test (CDT) is a cognitive screening measure with sound psychometric properties which has been well researched over the past century. The CDT is a popular tool for many healthcare professionals to administer independently or as part of a more thorough cognitive evaluation. Given the drastic technological and social developments over the years since the CDT was developed as well as the persistent research focus on older adult populations, a gap in the CDT literature presented for young adults, who may have difficulty drawing an analog clock. Identifying cognitive impairment can improve health outcomes. The young adult population requires an effective and accurate cognitive screening tool due to the incidence of traumatic brain injury including concussion, the need for pre-sports season physicals, and eventual maturation to older adulthood. Inaccurate CDT outcomes could result in unnecessary further testing, increased hospital length of stay, and avoidable emotional stress for the patient and family.

The first study explores CDT performance in young adults who self-identify as having normal cognition. Using the Shulman method of scoring, a significant proportion of the participants received a “failing” score on the CDT. Visuospatial skills were preserved in this population which suggests a lack of knowledge of analog clock times or language. The second study focuses on the clinical setting and compares CDT scores between young and older adult hospital inpatients. These data confirmed findings from the first study and determined a significant variance from young to older adults when categorized by overall cognitive severity ratings. The third study investigates the effect on cognitive severity rating in participants with a diagnosis of concussion or craniotomy who missed points on the CDT. Findings suggested a significant difference in cognitive severity rating between young and older adults for those participants with a diagnosis of concussion, again likely related to challenges in drawing an analog clock within the younger adult population.

As generational evolution is inevitable, it is vital to assess the current and future role of the CDT in cognitive screening for young adults. This three-paper dissertation offers further insight into the CDT ability of young adults with relevant recommendations and future research implications for interdisciplinary cognitive screening practice with this population.

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Dissertation-Campus Only

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