Leading computational neuroscientists and engineers have recently proposed the construction of a Human Brain Map, modeled after the widely successful Human Genome Project as an open-access collaboration between researchers to answer some of the most elusive questions about how brain function leads to human experience. First proposed in 2011 at a small meeting, the project has evolved, now receiving public support of US President Obama and widespread media coverage.
Prominent theories of brain function propose that conscious human perception of reality relies upon the distributed and dynamic interactions of brain circuits, which turn on and off in real-time. Currently available techniques such as functional magnetic resonance imaging and magnetoencephalography have long been used to investigate these kinds of circuit functions, however neither technique currently offers adequate spatial or temporal resolution to record from thousands of individual cells on the timescale that those cells operate. This technological inadequacy largely explains why brain imaging technology has had little impact on discerning “emergent principles of brain function” that this project is intended to address, which may be critical to development of treatments for often intractable disorders such as “epilepsy, depression, schizophrenia, autism, and dementia, [which] may emerge when large-scale interactions within the brain are disrupted”. A variety of motor disorders such as result from spinal cord injury or amyotrophic lateral sclerosis, might also be thought of as syndromes of brain-body disconnection and would fall under the purview of this project.
Accordingly, the primary goals of the Brain Activity Map set out in this initial proposal are to develop techniques and analysis methods to record for millions of brain cells simultaneously and selectively perturb the function of some of these cells at will.
This decades-long project would involve two core research paths operating in parallel. One path would promote the development of tools to study large-scale interactions in model organisms, initially focusing on the small-scale brains of invertebrate flies and worms to “spearhead … data acquisition and analysis and for theory development” before being scaled to the brains of larger vertebrates such as zebrafish, mice and rats. The second path would focus on developing related techniques which could be utilized in human brain research, such as might be possible when recording from the brains of surgery patients in a clinical setting.
The proposed timeline suggests that within five years tools will be available to record and perturb up today tens of thousands of cells simultaneously, which could be scaled to 10 and 100-fold over the next decade.
Numerous challenges lie ahead. New technologies will need to be developed in order to create “nanoscale neural probes that can locally acquire, process, and store accumulated data”, not to mention the need to develop new techniques to analyze the data in real-time.
Also unclear is exactly who will provide the funds for this audacious project. The proposal advocates both public and private funding but not at the expense of existing neuroscience initiatives. Although US president Obama has already expressed support for the plan, a cash-strapped American economy may put pressure on private initiatives to provide a backstop against current political headwinds if the project is to go forward.