Assignment 3 Report

VR Wild West Cognitive Test

Pitch

A fun spin on traditional cognitive testing, this VR application weaves reaction time and working memory “chimp tests” into a Western world with gun-driven gameplay.

Application Description

My application uses Virtual Reality (VR) to immerse players in a Western-themed virtual world where they can wield a gun to complete two common cognitive tests – a reaction time test, which has been redesigned as a Western shootout, and the “chimp” test, a number memory challenge originating from a study of chimpanzees’ impressive working memory (Inoue & Matsuzawa 2007).

A challenge of performing cognitive testing is that it is typically perceived as “effortful, frustrating and repetitive, which often leads to participant disengagement” (Lumsden et al. 2016, para 1).  Because of this, researchers are increasingly exploring the role of gamification in testing, with objectives such as increasing motivation, intuitiveness, long-term engagement and stimulation (Lumsden et al. 2016).      

The correlation between video games and cognition have come into focus in the field of neuroscience, where some benefits are apparent, but areas such as executive functions, memory and general cognition produce contradictory results, and more research is urgently needed (Kühn, Gallinat & Mascherek 2019).  Therefore, I have adapted two common cognitive tests into VR with shooting game mechanics in an application which could be used for comparisons of traditional and gamified/stylised cognitive testing.   

There were a few characteristics of VR hardware that made it a good fit for this purpose.  Given the theme of gun-driven gameplay, the size, form and button positioning of handheld VR controllers such as those for the Oculus/Meta Quest are ideal for facilitating input that more closely resembles real gun interactions than alternatives like a mouse or game controller.  VR hardware is also designed to run applications with a high framerate and low latency - for example, Oculus Quest 2 is receiving an update to make 120Hz a default setting (Hayton 2022) which should make it ideal for testing reaction time. 

Interaction Design

Storyboard illustrating user interactions

Users interact with a sequence of two alternating, increasingly difficult cognitive tests using a gun in a setting inspired by Western shootouts.  In a full implementation a greater variety of tests would be implemented, and a menu could be used to freely select individual challenges and adjust difficulty levels. 

For creating real-world feedback that matches the player’s virtual perception of firing a gun, the Oculus Touch controllers were ideal, as they have a trigger on the side of the handle which the middle finger curls around, and a front-facing trigger on the back of the controller which the index finger pulls.  To best match the affordances of a real gun, the side/handle trigger is for grabbing and the back trigger is for shooting.  Upon firing, the barrel of the virtual gun flashes, the controller briefly vibrates and a gunshot is heard, which together create a realistic experience that unites the senses of sight, sound and feel.

However, on the virtual side, realism is sometimes subverted for the user’s convenience.  Firstly, the gun is unaffected by gravity and positioned by default at the same level as the player’s hands, so it can be easily grabbed and released without being lost.  Releasing the gun pauses the automatic progression of tests if the player needs a rest.  Because the cognitive tests are designed to test reaction and memory, not gun accuracy, when the gun is held a line is rendered from the barrel to make it easier to aim at the targets.

Instructions, including the reaction signal, are given through text that appears above the cowboy enemy’s head – the default central point of the player’s vision.  The text is normally a bright red but turns green to either indicate the “Go!” signal for the shootout or that the player passed a test.  Upon the reaction signal, a shrill piano note also plays as an additional sensory cue.  Text also informs the player of their ranking e.g. “below average”, based roughly on the data collected by the Human Benchmark website for reaction (2022b) and chimp tests (2022a), but a full implementation would also consider the player’s age, gender and hand used to hold the gun, as these can all affect average reaction time (Jain et al. 2015).

For the chimp test, targets are positioned as a flat 2D interface rather than encircling the player in 3D.  In monitor-based chimp testing the user can view all the numbers together, and since this is key to the test this application presents the numbers in a similar way to ensure a fair comparison.  However, it could be possible for a future implementation to introduce a new kind of test where the player responds to surrounding stimuli which have 3D audio cues.

Technical Development

The application was made in Unity and developed using an Oculus Quest VR headset and touch controllers.  The player interacts with objects with a raycast that is projected from the grabbable gun object.

A challenge of developing consistent reaction tests using any kind of technology is input latency.  In an effort to reduce lag, when the controller trigger input is registered, the very next line of code stores the time that it was pressed, prior to any logical conditions being checked.  However, there is a good possibility that input lag is still present in the application and it would be necessary to complete proper performance testing and optimisation in future to ensure that the results are as accurate as possible.

With the chimp test the challenge was writing a suitable program to randomise the targets and the order that they would be shot in.  Because random number generation and looping was involved, issues with infinite loops, which freeze the Unity editor upon running the game, were frequently encountered at first.  The solution used a loop that makes an initial random selection, and from there runs a fixed loop if an initial target selection was invalid. 

Descriptions of 3D Models

This cowboy model by TA (2016) was used as the player’s opponent in the reaction test.  The model came with many animations, so I modified the animator controller and added parameters so that these animations could be triggered with code at the appropriate times in the shootout.  I also turned the included gun into a grabbable object for the player to use.

This military target model by NikiYani (2019) was used for the chimp test.  I added a canvas and text to the model prefab so that the targets could display the order that they needed to be shot in.

The scene contains some models from Dqurp’s Western Pack (2018), namely the Cactus and Western Wagon.

References

Devlog

Hayton, P 2022, Oculus Quest 2 is getting a faster default refresh rate, PCGamesN, viewed 18 Sep 2022, <https://www.pcgamesn.com/oculus/quest-2-faster-default-frame-rate-120hz>.

Human Benchmark 2022a, Are You Smarter Than a Chimpanzee?, Human Benchmark, viewed 31 Aug 2022, < https://humanbenchmark.com/tests/chimp>.

Human Benchmark 2022b, Reaction Time Test, Human Benchmark, viewed 31 Aug 2022, <https://humanbenchmark.com/tests/reactiontime>.

Inoue, S & Matsuzawa, J 2007, ‘Working memory of numerals in chimpanzees’, Current Biology, vol. 17, no. 23, pp. 1004-5.

Jain, A, Bansal, R, Kumar, A & Singh KD 2015, ‘A comparative study of visual and auditory reaction times on the basis of gender and physical activity levels of medical first year students’, Int J Appl Basic Med Res, vol. 5, no. 2, pp. 124-7.

Kühn, S, Gallinat, J & Mascherek, A 2019, ‘Effects of computer gaming on cognition, brain structure, and function: a critical reflection on existing literature’, Dialogues in Clinical Neuroscience, vol. 21, no. 3, pp. 319-330.

Lumsden, J, Edwards, E, Lawrence, N, Coyle, D & Munafò, M 2016, ‘Gamification of Cognitive Assessment and Cognitive Training: A Systematic Review of Applications and Efficacy’, JMIR Serious Games, vol. 4, no. 2.

Assets

Dqurp 2018, Western Pack, Unity Asset Store, https://assetstore.unity.com/packages/3d/environments/fantasy/western-pack-3116

NikiYani 2019, Military target, Unity Asset Store, https://assetstore.unity.com/packages/3d/environments/military-target-136071

TA 2016, Red Cowboy Fella, Unity Asset Store, https://assetstore.unity.com/packages/3d/characters/humanoids/red-cowboy-fella-59565

Terrain: Unity Technologies 2022, Terrain Sample Asset Pack, Unity Asset Store, https://assetstore.unity.com/packages/3d/environments/landscapes/terrain-sample-asset-pack-145808

Music + Reaction Signal: French, JL 2016, Western Audio & Music, Unity Asset Store, https://assetstore.unity.com/packages/audio/sound-fx/western-audio-music-67788

Handgun Sound Effect: Giradot, O 2019, Free SFX Asset Pack, Unity Asset Store, https://assetstore.unity.com/packages/audio/sound-fx/free-sound-effects-pack-155776

Scripting References

Rounding a number: https://answers.unity.com/questions/50391/how-to-round-a-float-to-2-dp.html