Our development of the BrainVR experience is rooted in our understanding of brain anatomy and recognizing the limitations of current anatomy education.
Observing In The Anatomy Lab
Years ago, I studied the anatomy of the brain while earning a Master’s degree in pathology. The brain, removed during autopsy, is a highly fragile gelatinous mass. Without the skull to give it support, the brain does not hold its shape very well. Quickly slipping the brain into a large bucket of formaldehyde solidifies the tissue for examination. After about a week of sitting in formaldehyde, the brain tissue is light tan-gray and about the consistency and of firm tofu.
At the brain autopsies I observed, a neuropathologist sliced the brain into 3 mm thick slices revealing irregular swirls and regions in shades of light and dark tan-gray. The instructor showed us the slices in sequence and asked us to pay attention to a particular structure in the brain, watching as it changed shape with each subsequent slice. The structure might appear in the first slice as just a speck. Then, with each subsequent slice, the area widens until reaching its maximum width. With further slices, it starts shrinking again, until no longer visible. From viewing the 2D brain layers, we were supposed to form a 3D model in our mind of that part of the brain; a task I can’t say I did successfully. Despite sitting through many hours of brain autopsies, I never formed a clear, 3D picture of the anatomy of the brain in my mind.
Applying Anatomy Education
In my current work on the research and content team at Health Impact Studios, we are building a 3D model of the brain for a virtual learning experience. Starting with a 3D human brain model (Zygote) that included a number of the structures of the brain, our team of 3D artists and video game design interns created models of additional structures of the brain to add detail to the model. Our developer team then added a way to move through the brain structures virtually, as if navigating inside the brain. The product allows students of brain anatomy and brain functioning to explore the brain themselves, developing a better understanding of the 3D anatomy of the brain. This method is better than looking at two-dimensional, static images or even slices of a brain.
As we worked to create a vivid learning experience, we made decisions on how realistic to make the brain model. Unlike many other models, we made ours with realistic blood vessels and coloring. But if we made the brain flimsy, it would be difficult for students to examine during their virtual experience. So, our model is more solid than a live brain and holds its shape, as if fixed in formaldehyde.
Balancing Realism and VR
As we constructed the model, we had to balance realism against the logistics of being able to navigate inside the brain. To create an open space in the model to move through, we had to leave out many brain structures. In most instances, we chose to leave out the brain’s white matter, which represents connections between parts of the brain made up of many nerve axons. With the white matter removed, there was enough space to move around inside the brain and look at the remaining structures, primarily gray matter, where the nerve cell bodies reside.
Another way we deviated from reality in our brain model was to display the functional subregions of the brain visibly. These are not visibly distinguishable in real life. The shape and function of these brain regions were defined by scientists through a variety of scientific techniques, from neurological testing and histological staining in early brain studies to positron emission tomography (PET) and various forms of MRI (including functional and diffusion MRI) more recently. For example, there is a specific area in the left temporal lobe of the brain (Wernicke’s area) that is involved in speech. When individuals have strokes involving this area, they have difficulty speaking. This area’s boundaries are not evident when looking at a brain specimen, but you will be able to interact with our model to see them.
Many more regions of the brain and their functions are of interest in the study of brain anatomy and included in our model of the brain. For example, the Ventral Tegmental Area (VTA), which is involved in the experience of pleasure and addictions, is included in our model. The challenge was how to show them, but keep them realistic. We wanted the user to know which part of their VR experience had fidelity with a live brain and which part was visually enhanced to display brain function (neurophysiology). We considered representing these regions using a translucent color overlay superimposed on the realistic brain tissue, This would make functional brain regions appear as a different color only after you interact with them.
These are the types of challenges we are grappling with as we attempt to create a multilayered virtual learning experience of the incredibly complex biological structure that is the brain. We invite you to try our demo and provide feedback on how we might improve the experience and provide a truly immersive exploration of the brain from the inside!