Brain Activity Map vs. Human Brain Project. America vs. Europe.
I, like the neuroscience community, can’t wait to see what will come from the race to gaining ‘complete comprehension’ of the brain’s neural workings. So I’ve compiled several sources and opinions on the proposed projects to try to understand what research will take place, and where we think it’ll lead.
The race began last month when Obama announced a decade long brain mapping scheme which certainly appears to be challenging the recently launched European lead Human Brain Project (HBP) to a neuroscience duel; the American Brain Activity Map see the HBP’s €1 billion investment, and raises its to $3 billion. The goals of these initiatives are to “examine the workings of the human brain and build a comprehensive map of its activity”  and “to reverse-engineer the human brain in computers” , respectively, and both in the space of a decade.
This injection of capital in neuroscientific research sounds familiar. In the ’90s a ‘Decade of the Brain’ was declared by George Bush, with an aim “to enhance public awareness of the benefits to be derived from brain research” . What can we expect this time around?
The Human Brain Project (HBP) in the Red Corner.
The executive summary of the HBP report delves a little deeper than the exuberant video below. It first describes the problem with modern neuroscience as it stands, which is that research focuses on various specific brain areas, and naturally this approach can never achieve a holistic understanding of the brain.
The proposed principles on which the computer model of the brain will be based include multi-level brain structure in mice. “Many results from studies of the mouse brain are applicable to all mammals” and these can help to understand and recreate the different levels of brain organisation in humans. Data will also be provided for differences between mouse and human brains, though trying to match the two as much as possible. On this foundation, The HBP claim one of its most important goals to be the understanding of the relationship between brain structure and function.
Ed Yong clarifies this in his Not Exactly Rocket Science post:
For over two decades, [HBP leader, Henry Markram’s] team have teased out the basic details of a rat’s neurons, and produced a virtual set of cylindrical brain slices called cortical columns. The current simulation has 100 of these columns, and each has around 10,000 neurons—less than 2 percent of a rat’s brain and just over 0.001 percent of ours. “You have to practice this first with rodents so you’re confident that the rules apply, and do spot checks to show that these rules can transfer to humans,” he says.
The HBP also wants a complete inventory (“the single-cell transcriptome”) of which genes are ‘switched on’ in different types of neurons. From this they expect to “use it to deduce the blend of different neurons in various parts of the brain, recreate the electrical behaviour of each type of cell, or even simulate how a neuron’s branches would grow from scratch” . They will also employ theoretical research to focus on “the mathematical principles underlying the relationships between different levels of brain organisation and the way the brain acquires, represents and stores information”.
As for the computer part, the project aims to create 6 integrated systems of ICT platforms dedicated to Neuroinformatics, Medical Informatics, High Performance Computing, Neuromorphic Computing, Brain Simulation and Neurorobotics. The latter two are to be used to understand and simulate the neuronal circuits responsible for specific behaviours including “genetic defects, lesions, and loss of cells at different levels of brain organisation and modelling the effects of drugs”. The idea is that these platforms will be able to be used in the future by researchers in neuroscience, medicine and technology development. By discovering “biological signatures associated with specific disease processes” and simulating the processes, advances should be made in the treatment and prevention of brain disorders.
(If you’re more hard-core than that, there’s always the full report.)
Reception to the HBP Proposal
From articles and blogs I’ve read, there doesn’t seem to be much confidence that a computer model of the brain will be made. The New York Times quoted brain researcher Haim Sompolinsky saying of the project:
The rhetoric is that in a decade they will be able to reverse-engineer the human brain in computers. This is a fantasy. Nothing will come close to it in a decade .
This is a view shared by neuroscientist and writer Vaughan Bell in his piece for Mind Hacks:
Essentially, it’s a problem of information architecture but quite frankly, you can’t sell that to politicians and they can’t sell it to the public. Hence the ‘simulating a complete human brain’ fluff.
Ed Yong’s post highlights the difficulty that already exists in creating computer models of just single neurons, never mind a brain full of them (which apparently add up to approximately 86 billion). He also states that even if the model did get that far, we can’t expect it to start talking or ‘behaving’ in any way, but mentions a project that does aim for just that.
In general, many neuroscientists have argued that we don’t know enough about the fundamental underpinnings of the human brain to be able to pull off these projects just yet. Erin C. McKiernan for Scientific American gives a guide to the ‘gaps in our knowledge’, for instance asking:
We know a lot about the composition of [the specialized contacts where neurons communicate] and the general rules of signal transmission. But important details are missing. Who is connected to whom? Where in single neurons are contacts located? What are the strengths of the connections, and how do strengths change under different conditions?
Now in the Blue Corner, the Brain Activity Map (BAM).
Across the pond, the US initiative seems to be based on a BAM project proposal published in Neuron by A. Paul Alivisatos and colleagues in June 2012. An interesting phrase in the proposal is “international public effort”. Regrettably, hopes of an international cooperative project went out the window when the HBP won European Commission funding in January. As noted by some, BAM appears a little less defined than the European project, which when added to the timing of Obama’s funding of $3 billion, can make the initiative come off as a hasty rebuttal to European competition to be at the cutting edge of neuroscience.
Competition aside, the Neuron article doesn’t sounds too dissimilar to the HBP, with their aim of “reconstructing the full record of neural activity across complete neural circuits”; BAM also wants to map all neural circuits and simulate them in computer models, too.
So what’s the difference?
Well, BAM pins its hopes and dreams of beating the HBP in the battle of the best brain project on the spike activity of neurons.
We propose to record every action potential from every neuron within a circuit — a task we believe is feasible.
Rather than use Single Electrode Recordings (a surgically implanted electrode between the brain’s meningeal layers – arguably quite an invasive technique!) to measure the firing of individual neurons, the paper claims that recording activity in neural circuits would be more advantageous in understanding the function of these neurons. The aim is to develop functional or active maps of the firings of neural circuits in the brain, as well as static maps which you can see in the adjacent image. Although the paper names a few recent studies featuring potential technology that could be used to map all this, they’re not without their faults, and it also admits that:
To date, it has not been possible to reconstruct the full activity patterns of even a single region of the brain. While imaging technologies like fMRI or MEG can capture whole-brain activity patterns, these techniques lack single-cell specificity.
In fact, it seems fairly certain that we won’t be seeing the mapping of the human brain in a decade’s time, as the paper sets a long-term goal of 15 years to reconstruct the neuronal activity of an awake mouse, let alone a human!
But scientists working on the US project still expect to unearth a lot more on the physiology of mental disorders including Alzheimer’s, Parkinson’s, autism and schizophrenia, as well as advances for technology, and of course the ambition of matching the widely parroted Human Genome Project economic success of generating $141 for every dollar invested.
Reception to the BAM Proposal
One of the anticipated benefits stated in the paper is the deciphering of the ‘neural code’. In a Cross Check post for Scientific American, John Horgan points out that the neural code would be a pretty handy thing to have already deciphered before attempting to record every neuron there ever was.
Neuroscientists have faith that the brain operates according to a “neural code,” rules or algorithms that transform physiological neural processes into perceptions, memories, emotions, decisions and other components of cognition. So far, however, the neural code remains elusive, to put it mildly.
So this is where the comparisons with the Human Genome Project end, as a deciphered genetic code was already under the belt before the project began. Without the brain’s equivalent of that figured out, it’s arguable that a basic foundation of mapping research is missing.
The Elusive Self blog discuss the implications (or lack thereof) of the project’s outcomes in relation to the mind.
The computer scientist David Marr noted that the mind can only be fully understood by linking three levels: the function of the system, the computations the system carries out, and how these computations are implemented in the brain. In its current form the majority of BAM funding will be thrown at understanding only one of his three levels: implementation.
Meanwhile, an article by Gary Marcus in The New Yorker even raises doubts as to whether all the data that would be accumulated from such projects will be of any practical use. This is considering the recent neglect of a release of data from the Human Connectome Project’s first stage, despite its initial prospects of significant neurological importance.
All this is without mentioning the concern of many, that such a powerful flux of funding in both projects could jeopardise the feasibility of proceeding with other research.
To sum up, although I’ve quoted several criticisms and sceptical thoughts of the neuroscience community on whether these big brain projects will achieve what they expect in the decade time-frame, it’s important to note that no-one doubts that the field of neuroscience will make leaps and bounds because of them. Perhaps complete and comprehensive computer simulations of the brain are less important that the potential minefield of findings that could be uncovered during the process.
Mentioned & Recommended Links
The Human Brain Project website
Alivisatos, A. P., et al. (2012). The Brain Activity Map Project and the Challenge of Functional Connectomics. Neuron, 74, 970-974.
Vaughan Bell, Mind Hacks – What will the billion dollar brain projects do?
Erin C. McKiernan, Scientific American – Challenges in Simulating a Human Brain
The Elusive Self blog – When tackling the brain, don’t forget the mind
Gary Marcus, The New Yorker – The Three-Billion-Dollar Brain
Brain Study blog – Billions of dollars to map billions of neurons
1. The New York Times – Obama Seeking to Boost Study of Human Brain
2. John Horton, Cross Check (Scientific American) – Do Big, New Brain Projects Make Sense When We Don’t Even Know the “Neural Code”?
3. Project on the Decade of the Brain
4. Ed Yong, Not Exactly Rocket Science – Will We Ever… Simulate the Brain?