Virtual reality transforms how we interact in our homes, in relationships between co-workers, and in many more ways. It is a technology that offers experiences that challenge the limits of our imagination and is constantly evolving.
But how does virtual reality work on a neural scale? Why does the brain perceive it so realistically? What are the positive effects of this technology? To find out the answers to these questions and more, continue reading and learning about the latest scientific evidence.
Immersive virtual reality in rehabilitation
Immersive virtual reality is a technology that uses software and hardware to create a simulated environment in which the user can interact in an immersive way.
It takes advantage of several principles to trick the human brain into perceiving and experiencing a virtual world as if it were real, such as those mentioned below:
Immersive virtual reality uses high-resolution displays and advanced optics to provide three-dimensional images to the user, along with a 360-degree field of view and a moving perspective. These images are rapidly updated to follow the movement of the user's head, creating a sense of presence in the virtual environment.
Another sensory stimulation used is spatial or three-dimensional sound to simulate direction and distance, adding realism to the experience.
Immersive virtual reality devices are equipped with motion sensors, such as gyroscopes and accelerometers in the controls and goggles, as well as motion capture cameras, which record the movements of the user's head and other parts of the body, such as the hands.
This data is used to update the view in real-time, which helps maintain a sense of presence and reduces the possibility of motion sickness.
Interaction and Feedback
When interacting with the virtual environment, such as touching, grasping, or moving virtual objects, the user receives visual, auditory, and haptic feedback that is integrated into the overall experience.
Immersion and Presence
The combination of a convincing representation and stimulation of the senses, along with the system's sensitivity to the user's natural response and interaction captured in the virtual environment, creates a sense of technological immersion.
"Presence" is the psychological term used to describe the feeling of being present in the virtual world.
The human brain is adapted to process sensory information and create perceptions of the world we are surrounded by. In VR, artificially generated sensory information that tricks the brain into accepting virtual reality as a genuine experience.
Similarly, it is interesting to note that according to the article Effect of specific over nonspecific VR-based rehabilitation on poststroke motor recovery: a systematic meta-analysis "a recent meta-analysis confirmed that the use of custom-built VR systems has significant benefits in the recovery of upper extremity function and activity compared to conventional therapies, but commercial video game VR-based therapy systems do not".
To understand the above, we must know what mirror neurons are and why they are so important in the motor rehabilitation process.
What are mirror neurons?
Mirror neurons are a special type of neurons that become activated when an individual performs a specific action and when they observe another person performing the same action. These neurons play a key role in the imitation process and are closely linked to learning and motor training.
Here are some more detailed examples of the effect of mirror neurons in our brains:
Imitating and Learning
Mirror neurons allow individuals to imitate actions simply by observing them. When we watch someone perform a task, mirror neurons are activated and help us understand and learn that action.
This is fundamental in motor learning, as it allows people to imitate observed movements and behaviors, thus facilitating the learning of new skills.
Visual and Motor Feedback
During motor training, mirror neurons compare their body movements with another observed one. This process of visual feedback aids in movement correction.
If there is a discrepancy between what is being attempted and what is observed, mirror neurons can help adjust and refine movements for a better match.
Empathy and Understanding
Mirror neurons are also linked to empathy and emotional understanding. By observing the actions and emotional expressions of others, these neurons allow us to understand and share the feelings and mental states of others, which is essential for social interactions and empathy.
Rehabilitation & Therapy
In the rehabilitation field, mirror neurons have been used in therapies to help people recover motor skills after brain injuries or strokes.
The observation of movements and the activation of mirror neurons can help in the reconstruction of neural connections and the recovery of lost motor functions.
In the context of sports training and other activities that require specific motor skills, the observation and imitation of gestures, facilitated by mirror neurons, are fundamental to developing and improving these skills.
The Key Role of Mirror Neurons in Motor Training
According to the article Interactive visuo-motor therapy system for stroke rehabilitation, "VR stimulates the internal sensorimotor system, possibly related to improved functional outcomes, in which a group of brain cells called mirror neurons play a crucial role."
The neurons are found in cortical and subcortical areas, which are related to motor control, specifically those related to primary, supplementary, and cerebellum. Mirror neurons also appear to be active during voluntary motor imagination.
Therefore, the primary motor cortex is one of the main centers of mirror neurons in the human brain and is a key cortical area that controls the muscles of the body that allow us to perform our daily activities.
Other Responses Occurring at Neural Scale
According to the article Effects of Virtual reality-based motor rehabilitation: A Systematic review of fMRI studies, virtual reality revealed changes in how brain patterns are activated and reorganized on both the affected and opposite sides of the brain in patients recovering from a stroke.
These results were found mainly in areas of the brain related to movement and sensation and were present in patients at acute, subacute, and chronic stages of post-stroke rehabilitation.
They associate this with an improvement in functional ability after receiving virtual reality (VR) therapy. Similar improvements were also observed in older people and patients with other neurological diseases.
VR therapy was shown to be effective in both neurological recovery and improved performance in older adults, and these effects were supported by functional magnetic resonance imaging evidence showing brain reorganization.
In conclusion, "most stroke-related studies showed a restoration of normality or an increase in activation patterns or relateralization in/to the ipsilesional hemisphere following VR therapy.."