Your data is only as good as the methods you apply to collect them. The measuring tools’ limitations are also the data’s. In cognitive neuroscience as well as psychology we constantly work on improving our measuring tools, such as updating questionnaires, improving neuroimaging or brain stimulation techniques. However, even if we were living in science-haven and our methods to collect data were as precise as we wish them to be, we had still another factor to take into account: the stimulus. As important as having the right measuring tools is having the right stimulus. Is it actually inducing what you want it to? What is the purpose of measuring a neural or behavioural response to a stimulus that does not evoke what you want it to? Hence, working on our stimuli is a key element of doing research involving human participants.
Usually in cognitive neuroscience and psychology, we choose stimuli as simple as possible to minimise the level of confounding variables. However, this sometimes results in an experimental situation being far from a real life environment. (As for example, making participants watch a clock that does not serve any purpose again and again.) But how can you get real life environments into the lab? Virtual Reality offers an exciting “new” tool to create situations much closer to real life than other stimuli, such as purely visual or verbal ones. (I’m saying “new” because the first prototype system was actually introduced in 1962 by Morton Heilig (Gaggioli, 2001).) In addition, it is possible to create extreme environments (as for example exposing the participant to fire), which would not pass any ethics committee and perhaps be rather dangerous to the participant.
For those unfamiliar with VR, the main difference to techniques commonly used in studying human cognition is that VR environments involve “closed loop” systems, in which the participant’s response to a cue determines the next view, and stimuli commonly used involve “open loop” systems, in which the participant’s response has no effect on the next stimulus presentation (Dombeck & Reiser, 2012). VR experiments involve a simulated environment that is sensed by someone and is updated by this person’s behaviour. The interaction must be parametric, that is, movements must map to the parameter space used to create the environment (Dombeck & Reiser, 2012). In contrast, the world presented to the participant in an open loop system does not change according to the participant’s behaviour, does not allow for any interaction and is, therefore, potentially less similar to the real world.
Assuming that a VR environment genuinely presents a real-world-like experience and given the appropriate equipment, you can for instance measure how a person moves around in that environment (e.g., using motion tracking) and how they respond to certain features. Many aspects of human cognition and perception can be studied using VR, as for example visual perception, visuospatial navigation, sensorimotor transformation, haptic perception, attention, memory and cognitive performance, to name a few (Gaggioli, 2001). But particularly exciting, with VR it is possible to combine senses, as for example visual, audio and tactile perception, and, hence, achieve multisensory integration. The way we move around in space, for example, is influenced by what we see, hear and feel (and by what we smell). With VR you can present people with an environment that includes visual and audio perception, let them run on a treadmill and measure their walking speed. So as it seems, VR is the future tool for psychological and cognitive neuroscientific research, however, I assume there are two issues or open questions:
Firstly, the question arises if we have the right skill set. VR only works if it is created skilfully and setting up a VR task requires a decent knowledge of programming. Hardly any researcher in psychology or cognitive neuroscience posses such a knowledge. Although the VR equipment toolboxes with the time inevitably do and will get more user-friendly, for now – as to my knowledge – there is still no graphical user interface of any of the commonly used programming softwares allowing you to create a VR task. This means that those who don’t have sufficient knowledge need to rely on someone else to create the task. This in itself is not bad, as collaborations between fields and departments can be very fruitful and an advantage for both parties, but it does not necessarily make setting up a study any easier and potentially limits researchers who don’t have connections to a computing department.
Secondly, what is probably the more important issue, we would need to get a clearer idea of whether a VR environment actually feels more real than “simple” one-level stimuli. After all, experiences are still restricted to what is written in the script. Although there has been some work done on assessing the use of VR in psychological therapy (e.g., Riva, 2005), there are surprisingly few studies comparing VR and commonly used instrumentation in cognitive scientific research. In fact, as far as I’m aware, there hasn’t been a single one of such studies. To know if a VR situation actually evokes a more realistic feeling or experience and if a participant’s response to a VR stimulus is more similar to the way they would behave in a natural setting, one would have to directly compare those two stimuli. If we find out that people are fooled as little by VR as by our commonly used open loop system stimuli, it would be unnecessarily spent time and effort to create a VR task to study human cognition. If, on the other hand, we find out it does make a difference, time and effort put in improving VR instrumentation and getting to grips with using the technique is well spent.
Naturally, there is still room for improvement in terms of technological and methodological factors. VR technology is becoming progressively cheaper (not the least thanks to big companies thriving the development and use of virtual world). Most likely, in a couple of years it will be even more easily accessible and give rise to better experiences. If we find that VR genuinely offers a stimulus option more representative of real life, we would be foolish not to put on our VR glasses and start exploring this world.
Dombeck, D. A., & Reiser, M. B. (2012). Real neuroscience in virtual worlds. Current Opinion in Neurobiology, 22(1), 3–10. https://doi.org/10.1016/j.conb.2011.10.015
Gaggioli, A. (2001). Using Virtual Reality in Experimental Psychology. Towards Cyberpsychology: Mind, Cognition, and Society in the Internet Age, 2(June), 157–174.
Riva, G. (2005). Virtual reality in psychotherapy: review. Cyberpsychology & behavior, 8(3), 220-230.