The pursuit of brain simulation — some challenges and considerations
Neuroscience has a fair grasp on how neurons use electrical and chemical signals to communicate between each other. The connections between each neuron and the rate of their impulses are generally what create our experience — our sensations, emotions, thoughts and even our desires — and are what allow us to physically interact with and interpret the world. Neurons are generally considered the building blocks of our conscious experience. So with this knowledge, and humans appetite for development, brain simulation is another step up the mountain of technological improvement. An improvement which requires efforts and considerations from many fields such as computer science, bioinformatics, neuroscience, data analysis and engineering. The idea of creating a computer based simulation of the brain also requires heavy considerations from ethical and legal bodies to safely and cautiously regulate the creation and implementation of a human-like ‘computer brain’. I’m sure many have heard the term brain simulation before, but what is it? What has and is being done by many organisations to achieve a working simulation of human experience. I will be exploring these questions below.
Brain simulation is the idea of imitating and hopefully emulating the natural brains connections and processes using a computer-based model. So far, scientists have successfully mapped and digitally simulated one small animals entire neural network. This organism is a microscopic worm called the Caenorhabditis elegans (C.Elegans). This primitive species has a very basic neural network consisting of 302 neurons which is infinitesimal to a human brain consisting around 80 billion neurons. Nevertheless, all connections in this tiny worm’s neural network have been mapped and digitally encoded into what is called a connectome; every one of its neurons with every one of the connections between them stored electronically. Using this information, a computer simulation has been developed allowing users to perform voluntary movements with a virtual worm precisely mimicking the actions of the C.Elegans producing all movements which you would normally see this animal doing. Some would say, the first step in our quest to brain simulation.
Currently, the Blue Brain Project (BBP) in Geneva Switzerland has made large strides in the pursuit to reconstruct the mammalian brain in a 3D digital environment. Their mission is exploring the possibilities of digital organisms and attempting to blend biology with the 1’s and 0’s of computers. By developing mathematical models and algorithms that imitate the electrical activity of neurons, BBP have simulated neuronal firing virtually. In addition to simulating the constituents of the mammalian brain, BBP have also created virtual environments allowing the simulated brain to perform in silico (meaning to be performed in a computer based software). One notable demonstration was brushing the whiskers of a simulated mouse which created a visual representation of the excited neurons which carry sensory information from the whiskers. This allowed the scientists from the BBP to show digitally, exactly where the sensation of the whiskers is integrated in the brain. It’s not hard to imagine how this software would improve basically all experiments on the anatomy and physiology of mammalian brains and even our own brain in the future.
The ability to simulate brushing the whiskers of a mouse shows the accuracy of the reconstructions and the future capability of the BBP to simulate other mammalian brains such as our own. Future steps by the blue brain project involve collaborations with the Human Brain Project to hopefully simulate the entire human brain which is considered the true goal.
So why do we have simulations on primitive worms and small mammals but not human brains? The primary barrier between scientist and a simulation of the human brain is the physical limitations of current technology, mainly computers. The supercomputer used in the Blue Brain Project is monstrous and at the peak of current performance in standard computers, but when you’re looking to map and simulate 80 billion neurons and 100 trillion synapses between them, you’re going to need to processing power and storage — and probably more than you might guess. If a simulation of billions of virtual neurons is going to work efficiently, machine power will need to accommodate the possibility of billions of neurons firing simultaneously, as this is how real brains operate. Current computation, memory and processing power just can’t handle the demand of almost incomprehensible amounts of connections sending and receiving information at once. Although transistors on computer chips are decreasing in size and increasing in numbers. The improvements in computer hardware are starting to reach physical limits as the size of transistors can’t be built much smaller. With physical limitations of computers and the enormity of the human brains connections, a challenging problem needs addressing. It is estimated that to store the human connectome using the same methods as the BBP, it would require 1 zettabyte of storage¹ (over 1 trillion gigabytes).
How to surmount the issue of computer power and storage? There’s no definitive answer yet, but quantum computers might pose a solution. Some giants in the industry such as IBM and google are fiercely working towards building a user-friendly quantum computer². Quantum computers utilise qubits — which unlike ordinary binary — can be superimposed, which put simply, means these qubits can be in two states simultaneously. This differs from standard computers binary digit system of 1 and 0 which can only be in one state at a time. A quantum computer with just 50 qubits could outperform the most efficient and expensive binary computers on the market³, leading us closer to processing power and memory performance we need to create a human-like brain simulation.
With both improvements and limitations aside, brain simulation generates a few controversial ethical questions. One interesting question asks, if a digital brain has consciousness, is it a computer or a brain? And if this digital brain has attention, memory and perhaps even thoughts and emotions, will this simulation have entitlement to human rights and be accountable to law? I have already discussed that our experiences are the aggregate of synaptic connections between billions of neurons. So, if we can simulate these connections, we could theoretically simulate experience. Could we simulate pain or joy? I don’t know but it is an interesting question which may be answered sometime in the future. With which, laws and regulation should already be in place to protect all concerns.
Using brain simulations with robotic hardware seems like a very possible outcome. This possibility leads to a concern on ‘dual use’ which is the intended use of technology and methods for medical or other civilian purposes initially, but inevitably being extended to military use. The use of robots with ‘human brains’ for military purposes seems like science fiction but nonetheless the human brain project and other organisations refrain from accepting funding from all military bodies⁴. The concept of brain simulation breeds many interesting debates on the possible applications of the technology (such as AI) and the appropriate regulation which I’m sure fans of the terminator franchise, are avidly aware of.
Check out the Humm Tech website to keep up to date with us, as we explore cognitive improvements via non-invasive brain stimulation.
- Wikipedia. Brain Stimulation [Internet]. Wikipedia, The Free Encyclopedia; 4 April 2018. Available from: https://en.wikipedia.org/wiki/Brain_simulation
2. Will Knight. IBM Raises the Bar with a 50-Qubit Quantum Computer [Internet]. MIT Technology Review [05/04/2018]. Available from: https://www.technologyreview.com/s/609451/ibm-raises-the-bar-with-a-50-qubit-quantum-computer/
3 Emerging Technology from the arXiv. Google Reveals Blueprint for Quantum Supremacy [Internet]. MIT Technology Review [05/04/2018] Available from: https://www.technologyreview.com/s/609035/google-reveals-blueprint-for-quantum-supremacy/
4. Rose N. The human brain project: social and ethical challenges. Neuron. 2014 Jun 18;82(6):1212–5
