An international research team has produced the first-ever ultra-high resolution 3D digital reconstruction of a complete human brain. At the astonishingly low resolution of 20-microns, the new scans are providing an unprecedented glimpse into the inner workings of the mind.
And remarkably, it could also be seen as a precursor to brain preservation and mind uploading. But more on that in just a bit. First, the breakthrough.
It’s called BigBrain, and it’s a part of the $1.6 billion European Human Brain Project that's seeking to simulate the human brain on a supercomputer. Over the course of the next ten years, HBP researchers will work to understand and map the network of over a hundred billion neuronal connections that elicit emotions, volitional thought, and even consciousness itself. And to do so, the researchers will be using a progressively scaled-up multilayered simulation running on a supercomputer.
But to get there, the researchers are going to have to peer deep inside the human brain. Hence the BigBrain project. Here’s how they did it.
Slice 'n Scan
First, the researchers took a 65-year-old female human brain embedded in paraffin wax. Then, using a special large-scale tool called a microtome they cut it into 7,400 individual slices each measuring 20-microns thick.
These histological sections were then mounted on slides, stained to detect cell structures, and then digitized with a high-resolution flatbed scanner.
The entire process took 1,000 hours.
Using this data, the researchers then reconstructed the high-resolution 3D brain model on a computer. Each slice had to be painstakingly aligned and reconstructed.
From the Macroscopic to the Microscopic
Traditional brain scans are great, but they only produce data at the macroscopic level. What’s required is ultra-high resolution in three dimensions. The new anatomical tool does just that, allowing scientists to see parts of the brain at a resolution of 20-microns — a distance smaller than the size of one strand of human hair. This is a spatial resolution that improves upon previous techniques by a factor of 50.
Here's a video produced by the researchers:
The new scans show the fine details of the brain’s microstructure down to the cellular level. What they’ve created here is a neurological atlas for small cellular circuit data, or single layers or sublayers of the cerebral cortex.
Using this map, scientists hope to gain important insights into the neurobiological basis of cognition, language, emotions, and other processes. It’ll help them study neurodegenerative disorders. They’ll compare this data to fMRI brain scans. And they’ll be able to generate a brain model with a resolution of one micron to capture details of single cell morphology.
The 3D aspect is particularly important. The human cerebral cortex is very heavily folded, making it difficult to determine thickness and other proportions with standard scanning techniques. What’s more, the cerebral cortex’s thickness changes over the course of a lifetime and is also affected by aging processes, including those linked with Alzheimer’s disease. The new technique overcomes these limitations, allowing scientists to understand the structure of different functional areas, including the motor cortex and regions important for learning and memory.
The Map is Not the Territory
There is a risk, however, of overstating the importance of this breakthrough.
As it has often been said, anatomy is not explanation. Just because we have a remarkably fine map of the human brain doesn’t mean that we’ll be able to understand it. No doubt, it will certainly help. But neuroscientists will still need to confer with cognitive scientists and other specialists if we ever hope to gain a full understanding of the human mind.
The researchers are also unduly optimistic when it comes to their timelines. They plan to simulate the entire human brain — from the molecular level to the interaction of entire brain regions — on a supercomputer in ten years. I think that’s highly unlikely. But they are on the right track by developing these sorts of techniques.
The path to uploads?
As noted earlier, the technique could also be seen as a precursor to mind uploading — the process of transferring or copying an existing human brain to a separate substrate. This latest breakthrough is a far cry from where we need to be, but it’s definitely a sign of things to come.
And in fact, Kenneth Hayworth is working on this exact sort of thing. He’s the president of the Brain Preservation Foundation and senior scientist at the Howard Hughes Medical Institute's Janelia Farm Research Campus. He’s the co-inventor of a highly advanced brain slicing machine that can image neural circuits at the nanometer scale. Hayworth has designed and built several automated machines to implement this process.
The ultimate goal is to preserve the brain’s informational integrity for later reanimation.
Eventually, we’ll be able to scan brains at such a high resolution that the information that constitutes a person — a person’s very essence that’s embedded within the brain’s molecules and their precise orientation — could be reconstructed at an alternate location. Assuming we could perform a kind of conversion where we transform biological information to digital form (i.e. algorithmic equivalents), we may be able to rebuild a brain based on information like this.
Needless to say, we’ll need to scan at an insanely high resolution to capture the degree of information needed. Not only that, the amount of data required — including quite possibly the location of individual atoms — will be horrendous. But there’s no reason to believe that computers of the future won’t be up to the task.