## 1 Introduction
### Development of Functional Object Detection Scenario  
Similar to other studies, researchers have used driving simulators in research settings to investigate driving performance and in clinical settings for patient evaluation and rehabilitation [33; 34; 35]. Simulators provided a valid, reliable, clinic-based tool for OTs to assess critical skills associated with independence and fitness to drive older adults for assessments and interventions [36]. Our team has developed a small footprint driving simulator that meets the needs of a diverse range of clients, while being designed for use in clinical settings [37; 38]. Research simulators used in universities often have large, wrap-around display screens that provide the driver 180 to 360-degree field of view. Although these immersive displays are realistic, the large field of view can overwhelm users with the strong illusion of motion, especially those sensitive to simulator sickness [39]. Large, immersive simulators typically require too much space and are too expensive and complex to operate for most clinical environments [37]. The simulator used in this study was developed to maximize the strengths of simulation using a small footprint [40].  
Our team developed the Functional Object Detection (FOD) driving scenario designed to assess participants' functional scanning ability within a virtual, driving context [41]. The inspiration for FOD came about as a result of the first author having multiple loved ones with glaucoma or macular degeneration; while each of the individuals had significant visual deficits, neither the patient nor many of their family members understood the dangers of their condition to driving risks. Therefore, FOD was designed to assess a driver's ability to maintain their lane positioning, drive the posted speed limit, detect brake lights on the lead vehicle (central vision task) and respond to visual stimuli in the periphery. This allows for a controlled, virtual driving tool that can be used for both assessment and training. This task was developed to address physical functioning (e.g., gross motor control, endurance, hand/eye/foot coordination, and motor planning), cognitive functioning (following directions, short term memory, processing speed, cognitive endurance, divided attention, selective attention, etc.), and visual functioning (visual field, pursuits, fixation, visual detection and discrimination, processing speed, etc.).  
In previous studies, the FOD driving scenario has been shown to be an effective tool to assess scanning ability in a realistic driving context and to have clinical utility in addressing reaction times and visual scanning deficits [41; 42]. Compared to the original FOD task which has four possible configurations (e.g., cruise control on/off), the Functional Object Detection--Advanced (FOD-A) task was specifically designed to allow the clinician to select from numerous combinations of variables to create the activity which best meets the specific needs and goals for each individual client. For example, when working with a client who is regaining skills after a stroke, it is possible to set the cruise control and a steering lock, where no steering inputs are required, so the client can focus solely on the visual tasks before increasing the workload associated with speed maintenance and steering tasks. For clinicians to make objective and flexible treatment plans for diverse client needs, FOD-A was developed to be utilized by a broad range of healthcare professionals as well as individuals outside of the healthcare arena.