PRESENTACIÓN DE RESULTADOS

1.7.1 Clinical Tests that Underlie Driving Performance Deficits

The findings in the literature identify three gaps that make it difficult to understand if a driving simulator can measure driving performance deficits in those with MS. First, on-road and driving simulator studies show inconsistent findings for which visual and cognitive impairments indicate deficits in driving performance. On-road studies show that impairment in visual acuity, complex attention, executive function, information processing speed, visuospatial ability, and working memory underlie driving performance impairment (Akinwuntan et al., 2018; Akinwuntan, Devos, et al., 2012; Akinwuntan, O'Connor, et al., 2012; Classen et al., 2018; Krasniuk, Classen, Monahan, et al., 2019;

Lincoln & Radford, 2008; Morrow et al., 2018; Schultheis et al., 2010).

When compared to on-road studies, driving simulator studies include tests that measure the same cognitive domains: i.e., complex attention (Devos et al., 2013; Lamargue-Hamel et al., 2015; Marcotte et al., 2008; Raphail et al., 2020), executive function (Devos et al., 2013; Lamargue-Hamel et al., 2015; Marcotte et al., 2008; Raphail et al., 2020),

information processing speed (Devos et al., 2013; Harand et al., 2018; Kotterba et al., 2003; Lamargue-Hamel et al., 2015; Marcotte et al., 2008; Raphail et al., 2020), visuospatial ability (Devos et al., 2013; Lamargue-Hamel et al., 2015), and working memory (Devos et al., 2013; Harand et al., 2018; Kotterba et al., 2003; Lamargue-Hamel et al., 2015; Marcotte et al., 2008; Raphail et al., 2020). Furthermore, three driving simulator studies included visual or cognitive tests that on-road studies found to indicate driving outcomes (Devos et al., 2013; Harand et al., 2018; Lamargue-Hamel et al., 2015).

The tests included the Stroke Driver Screening Assessment (Devos et al., 2013), Stroop Colour and Word Test (Lamargue-Hamel et al., 2015), SDMT (Harand et al., 2018;

Lamargue-Hamel et al., 2015), and an assessment of visual acuity (Devos et al., 2013).

However, study findings showed auditory information processing speed, divided

attention, and working memory to indicate driving simulator performance in drivers with MS (Devos et al., 2013; Harand et al., 2018; Lamargue-Hamel et al., 2015). Whether the same visual and cognitive impairments and clinical tests that underlie deficits in on-road outcomes can also underlie deficits in driving simulator outcomes is not fully understood.

1.7.2 Driving Maneuvers, Errors, and Environments that Indicate Driving Performance Deficits

Second, on-road and driving simulator study findings consistently show that adjustment to stimuli errors may underlie driving performance impairment in drivers with MS (Classen et al., 2017; Classen et al., 2018; Devos et al., 2013; Devos et al., 2017; Harand et al., 2018; Kotterba et al., 2003; Krasniuk et al., 2020; Krasniuk et al., 2017). However, on-road studies document driving errors as the total number throughout the entire on-road assessment or per environment (e.g., suburban, urban). In comparison, driving simulator studies document the drivers’ operational maneuvers when responding to stimuli across trials or throughout the duration of a highway drive, and not often in suburban or urban environments (Devos et al., 2013; Harand et al., 2018; Kotterba et al., 2003).

Overall, these findings make it difficult to understand whether operational and/or tactical adjustment to stimuli errors can indicate driving performance impairment in drivers with MS; and whether such errors can be detected in suburban and/or urban environments of a simulated scenario. Understanding if such simulated maneuvers, errors, and environments can detect driving performance impairment in drivers with MS may help develop targeted driving simulator assessments that may be used to inform fitness to drive decisions.

1.7.3 Feasibility of Utilizing Clinical Tests to Detect Driving Simulator Performance

Third, the feasibility of utilizing clinical tests to detect driving simulator performance in drivers with MS is not well studied. Feasibility is important for understanding the advantages, challenges, practicability, and capability of implementing a study based on participant recruitment methods, data collection procedures, outcome measures,

participants’ acceptability and suitability of testing procedures, resources required to manage and implement the study, and preliminary test results (Orsmond & Cohn, 2015).

Based on the existing literature, little is understood about challenges with recruitment (e.g., low recruitment rates), data collection procedures and outcome measures (e.g., simulator malfunctions), participants’ acceptability (e.g., perceptions on simulator’s usefulness or usability) or suitability toward the driving simulator (e.g., occurrence of SAS), or the resources and management required to implement the study (e.g., costs).

Determining the feasibility may provide insight to the challenges of driving simulator assessments for drivers with MS, including confounding variables that may affect driving performance such as the occurrence of SAS.

1.8 Dissertation Rationale

The rationale for this study derives from three fronts. First, because the feasibility of utilizing clinical tests to indicate driving simulator performance in drivers with MS is not well studied, little is understood about the challenges associated with driving studies or driving simulators that can impact participation and adherence rates, complete data collection, and test results. Accordingly, this dissertation will examine this gap in the literature. Understanding the feasibility of the study will indicate the advantages, challenges, practicability, and capability of factors that may impact study findings and whether to execute a full-scale study.

Second, the inconsistency between on-road and driving simulator study findings for which visual and cognitive impairment can indicate driving performance deficits

identifies the need to determine whether the same clinical tests found to underlie on-road driving performance can also underlie driving performance on a driving simulator.

Understanding this gap in the literature may provide insight to whether driving simulator assessments may be used as a substitute to assess fitness to drive in people with MS.

Third, the inconsistency between on-road and driving simulator study findings for which driving maneuvers, environments, and errors can detect driving performance impairment in drivers with MS make it difficult to understand if such errors can be detected on a driving simulator. Understanding whether operational and/or tactical adjustment to stimuli errors in suburban and/or urban environments can indicate driving simulator performance impairment in drivers with MS may guide fitness to drive decision-making.