Table 4.

Virtual reality-based technologies in a street environment for assessment and rehabilitation.

	Study Design	Participants	Purpose and targeted domains	Interaction, display and level of immersion	Assessment/Rehabilitation	Outcome Measures	Conclusions
Naveh et al. (2000)	Experimental	6 HC and 6 stroke with USN	Assessment and Rehabilitation of Attention, Street crossing consciousness.	15” CRT monitor or projected on a screen via video projector, keyboard and mouse. - Semi-Immersive	The participants’ task was to commence crossing the street when, in his or her opinion, it was safe to do so. The number of training sessions varied from 1 to 4, and the duration of each session varied from 30 to 60 minutes.	Instruments: BIT; MSC and ADL’s questionnaire. Performance: Frequency, order and direction that participants searched for oncoming vehicles; number of trials and total time to successfully complete each level; highest level successfully completed; time taken at each level of difficulty to cross the virtual street safely; number of accidents at each level; number of times looking to the left and to the right before crossing the street.	The performance of the patients was considerably more variable; they were able to complete fewer levels and usually took more time to do so. The results indicate that the VR training could be beneficial to people who have difficulty with street crossing.
Wald et al. (2000)	Non-experimental	28 TBI	Assessment of Perception (drive performance)	DriVR and HMD - Fully Immersive	Concurrent validity of the DriVR was examined by comparing DriVR measures to other indicators of driving ability, which consisted of on-road, cognitive and visual-perceptual, and driving video tests. The entire driving assessment occurred over a 2-day period within the same week.	Instruments: DPT II; DRI II and On-road Driving test. Performance: Follow traffic event; shop road and opposite road; stop signs missed; driveway choice event and avoid traffic event.	The DriVR appeared to be a useful adjunctive screening tool for assessing driving performance in persons with ABI.
Weiss et al. (2003)	Experimental	6 stroke with USN and 6 HC	Assessment and Rehabilitation of Attention, Street crossing consciousness.	Screen, Keyboard and mouse - Non-Immersive	The subject’s task was to commence crossing the street when, in his or her opinion, it was safe to do so. In the initial study, the number of training sessions varied from 1 to 4. During the intervention study, there were 12 training sessions given over a period of four weeks. In each configuration, the levels of difficulty were graded from 1 to 7.	Performance: Frequency, order and direction searching for oncoming vehicles; number of trials as well as the total time it took to successfully complete each level; highest level successfully completed; time taken at each level to cross the virtual street safely; number of accidents at each level; number of times looking to the left and to the right before crossing the street.	This VE was suitable in both its cognitive and motor demands for the targeted population. The VR training is likely to prove beneficial to people who have difficulty with crossing streets.
Katz et al. (2005)	Experimental	19 stroke participants with USN	Assessment of Attention, street crossing consciousness.	Computer desktop, keyboard and mouse - Non-Immersive	Experimental group was given computer based VR street crossing training and control group was given computer based visual scanning tasks, both for 9 hours distributed in twelve sessions for four weeks.	Instruments: BIT; MSC and ADL checklist. Performance: Number of looks to the left; number of looks to the right and number of accidents.	Both groups improved similarly. The VR group achieved on the USN measures results that equaled those achieved by the control group treated with conventional visual scanning tasks.
Titov and Knight (2005)	Non-Experimental	3 participants with neurological injuries	Assessment of Prospective memory	Touchscreen connected to a laptop - Non-Immersive	Virtual Street: a street that participants can ‘walk’ along. It has distracting sounds (car horns, people talking, music, news reports). Animations, such as people walking on the scene have been added. Prospective memory can be tested using the Virtual Street environment by instructing participants to complete errands as they walk along.	Instruments: WMS-III Digit Span; NART Word Lists; WCST; F-A-S Verbal Fluency and Stroop Test. Performance: SMT and CMT.	The patient performed more poorly on the multi-tasking test than the matched control. Patients performance in the computer-based tests was consistent with their memory deficits.
Lloyd et al. (2006)	Non-Experimental	20 ABI and 14 HC	Assessment and Rehabilitation of Route Memory	Playstation 2 games console and TV - Non-Immersive	Driv3r is based upon real-world town of Nice, and contains a large network of streets and buildings. It also features drivers and pedestrians moving around. Study 1: HC were driven around the real street and then had to give directions to the driver in the virtual street and contrariwise in a counterbalanced order. Study 2: Participants learned one route in an errorless way, watching the entire route correctly through completion three times before attempting to call out directions themselves. Another route, they learned in an errorful way, being shown the correct route only once before being asked to take two practice attempts (during which errors typically occurred) at calling out the directions before the final, ‘test’ trial.	Performance: number of wrong turns, number of errors, used strategies.	The first study demonstrated the ecological validity of a non-immersive virtual town, showing performance therein to correlate well with real-world route learning performance. The second study found that a rehabilitation strategy known as ‘errorless learning’ is more effective than traditional ‘trial- and-error’ methods for route learning tasks.
Kim et al. (2007)	Experimental	10 stroke and 40 HC	Rehabilitation of Unilateral neglect	HMD and Mouse - Fully Immersive	The training procedure consisted on completing missions while keeping the virtual avatar safe during crossing the street in a VE.	Instruments: MMSE; line bisection and cancellation test. Performance: deviation angle; reaction time; right and left reaction time; visual cue; auditory cue; failure rate of mission.	The system was proper to the training of unilateral neglect patients.
Akinwuntan et al. (2009)	Experimental	73 stroke	Rehabilitation of Cognitive training	Driving simulator - Semi-Immersive	Forty-two participants received simulator-based driving training, whereas 41 participants received cognitive training for 15 hours.	Instruments: CARA.	Simulator-based driving training improved driving ability, especially for well educated and less disabled stroke patients.
Devos et al. (2009)	Experimental	73 stroke	Rehabilitation of Cognitive training (driving retraining)	Driving simulator - Semi-Immersive	Forty-two participants received simulator-based driving training, whereas 41 participants received cognitive training for 15 hours.	Instruments: TRIP; CARA.	Contextual training in a driving simulator appeared to be superior to cognitive training to treat impaired on-road driving skills after stroke.
Lloyd et al. (2009)	Experimental	20 ABI (8 TBI, 6 stroke, 6 others (brain tumor and cortical cysts)	Assessment and Rehabilitation of Learning (Route learning)	Screen and Ps2 - Non-Immersive	For the demonstration trial and two learning trials, participants were shown around a route. As in the errorless condition, participants were asked to watch as the experimenter moved along the route and called out directions in the demonstration trial. For the test trial participants were asked to call out the directions at each junction.	Instruments: ROCF; AMIPB (List Learning). Performance: Wrong turns and errors made.	Route recall following the errorless learning was significantly more accurate than recall after errorfull learning. This suggests that the benefits of errorless over errorfull learning in ABI rehabilitation extend beyond verbal learning tasks to the route memorization task.
Sorita et al. (2013)	Non-experimental	27 TBI	Assessment of Learning (route learning)	Screen and joystick - Non-Immersive	Two immediate and one delayed route recall assessing procedural learning in spatial memory. The two tasks were performed within two modalities: route learning within a RE district and route learning within a virtual reproduction of the urban district (VE).	Instruments: GCS; TEA and GBT. Performance: Sketch map test; Map recognition test; Scene arrangement test; VE design.	The routes learned within the VE transferred better to the real setting than the routes directly learned in the RE. Therefore VR might provide ecological rehabilitation scenarios to assess daily functioning.
Navarro et al. (2013)	Experimental	32 stroke (15 non-USN and 17 USN) and 15 HC	Assessment of Arousal, Attention, Consciousness. (Street crossing).	Screen, infrared tracking system and joystick - Non-Immersive	The assessment session consisted of two consecutive repetitions of virtual street crossing. In each session, the participants were asked to move from the starting point to a large department store and then to come back as quickly and safely as possible.	Instruments: BIT; CPT-II; Stroop Test; CTT; BADS (Zoo Map and Key Search Test). Performance: Time to complete the task; number of head turns, accidents and warning signs.	The performance of neglect participants was significantly worse than the performance of non-neglect and HC.
Park (2015)	Experimental	30 stroke	Assessment of Incidence of driving errors	Driving simulator (GDS-300, Gridspace) - Semi-Immersive	Virtual on-road course with road traffic rules. The test course simulated driving in downtown Seoul and on the highway and was designed to resemble actual driving, incorporating various buildings, moving cars, traffic signals, and road signs.	Performance: Failure to use seat belt; exceed speed limit; turn signal errors; drop out the course; cross center line; accidents; brake reaction time and total error score.	Patients with lesions in the left or right hemispheres showed differences in driving skills, such as: frequencies of center line crossing, turn signal errors, accidents, brake reaction time, total driving errors and test failure rate.
Ettenhofer et al. (2019)	Experimental	17 TBI	Assessment and Rehabilitation of Dual processing, attention, working memory, and response inhibition	General Simulation Driver Guidance System: 8-foot circular frame supporting a curved screen and a driving console analogous to that found in a typical automobile - Semi-Immersive	1) Brief review of training and progress; 2) practice of cognitive skills through cognitive driving scenarios; 3) practice of composite driving while performing working memory or visual attention tasks; and 4) open-ended race-track course to promote engagement.	Instruments: WAIS-III (Digit Span, Symbol Search, Coding); TMT A and B; Letter and Animal Fluency; CVLT-II; Grooved Pegboard; NSI; PTSD Checklist-Civilian; BDI-II; SWLS; SF-36 (physical and mental); ESS and FSS. Performance: VR Tactical and Operational Driving Quotient.	NeuroDRIVE intervention enabled significant improvements in working memory and selective attention.
Spreij et al. (2020a)	Experimental	138 stroke and 21 HC	Assessment of Visuo Spatial Neglect	Large Screen + steering wheel - Semi-Immersive	Participants were instructed to use the steering wheel to maintain the starting position at the center of the right lane, which is in line with Dutch road traffic regulations. Participants needed to adjust their position continuously.	Instruments: Shape Cancellation Task; Catherine Bergego Scale. Performance: Average position on the road and the average standard deviation of the position, as an indication of the magnitude of sway.	Patients with left-sided VSN and recovered VSN deviated more regarding position on the road compared to patients without VSN. The deviation was larger in patients with more severe VSN. Regarding diagnostic accuracy, 29% of recovered VSN patients and 6% of patients without VSN showed abnormal performance on the simulated driving task. The sensitivity was 52% for left-sided VSN.
Wagner et al. (2021)	Non-experimental	18 stroke (9 USN and 9 No USN)	Assessment of Unilateral Spatial Neglect	iVRoad HTC Vive Controller - Fully Immersive	The task consists of dropping a letter in a mailbox on the way to work. To do so, the user first has to safely cross two roads and the square in between, and then return to the starting position to continue his/her way to work.	Instruments: IPQ; USEQ; SSQ. Performance: Error rate; decision time (elapsed time between task onset and start of road crossing by button press); Head direction ratio between the time patients looked left and right before making the decision to cross the street.	Parameters and conditions for distinguishing patients with and without USN were identified: Decision time has been identified as a very good measure. Error rate and the Head direction ratio were also reliable measures of separation.

ADL checklist, Activities of daily living checklist; AMIPB, Adult Memory and Information Processing battery; BADS, Behavioral Assessment of the Dysexecutive Syndrome; BDI-II, Beck Depression Inventory; BIT, Behavioral Inattention Test; CARA, Center for Fitness to Drive Evaluation and Car Adaptations; CMT, Complex Multi-tasking Test; COWAT, Controlled Oral Word Association Task; CPT-II, Conner’s Continuous Performance Test-II; CTT, Color Trail Test; CVLT-II, California Verbal Learning Test II; D-KEFS, Delis–Kaplan Executive Function System; DPT-II, Driver Performance Test II; DRI-II, Driver Risk Index II; ESS, Epworth Sleepiness Scale; FAS, FAS Verbal Fluency Test; FSS, Fatigue Severity Scale; GBT, Grober and Buschke’s test; GCS, Glasgow Coma Score; IPQ, Igroup Presence Questionnaire; MRMTDS, Money Road Map Test of Direction Sense; MSC, Mesulam Symbol Cancellation test; NART, National Adult Reading Test; NSI, Neurobehavioral Symptom Inventory; ROCF, Rey Osterrieth Complex Figure Task; SMT, Simple Multi-tasking Test; SSQ, Simulator Sickness Questionnaire; SWLS, Satisfaction with Life Scale; TEA, Test for Assessment of Attention; TMT, Trail Making Test; TRIP, Test Ride for Investigating Practical fitness to drive; USEQ, User Satisfaction Evaluation Questionnaire; VSN, Visuo Spatial Neglet; WAIS, Wechsler Adult Intelligence Scale; WCST, Wisconsin Card Sorting Test; WMS III, Wechsler Memory Scale III.