December 30, 2013
Neurotechnology: from curing the brain to understanding the mind
John P. Donoghue, Ph.D,
Director,Brown Institute for Brain Science
Professor of Neuroscience and Engineering
Brown University, Providence, Rhode Island USA
Neural Engineering is a rapidly expanding field creating neurotechnology to restore lost functions like
movement, vision or hearing. These brain interfaces, some now regularly implanted to treat brain
disorders, are also providing unprecedented access to the human brain to understand its function at
new levels of detail. In my presentation, I will first discuss the range of existing and emerging
neurotechnologies and then describe my group’s progress in creating a useful brain computer interface
(BCI) to restore independence, communication and control for people with paralysis. A BCI provides a
new communication channel to bypass damaged motor pathways from the brain. BrainGate, the first
intracortical BCI system in a human clinical pilot trial, is being developed by our group at Brown
University and Massachusetts General Hospital. The goal of BrainGate is to restore functions
performed by the arm and hand for people with paralysis. BrainGate employs a 4 x 4 mm array of 100
microelectrodes that is chronically implanted into the motor cortex (MI) arm area. This intracortical
sensor is intended to provide longterm access to MI neural ensemble activity as a direct source of
action command signals. Decoded signals, provided by MI activity when the user thinks about moving
their arm, can be used by people with longstanding paralysis to control computer cursors and robotic
arms. Our work has also revealed several important fundamental aspects of human motor cortex
function. First, local MI regions form integrated reach and grasp networks. Second, MI networks can
be engaged merely by imagining actions without performing them. Third, neural circuits retain a
relationship to arm actions years after paralysis onset, suggesting that representational plasticity does
not occur. Creating flexible, long-lasting BCIs for people with paralysis will require optimization of
sensors, fully implanted wireless systems, and better understanding of the neural processes encoding
arm action. These steps, which are well underway, have the potential to create a useful BCI able to
restore reach, grasp and dexterous manipulation for humans with paralysis of their arm. They will also
continue to provide insight into human brain function at the cell ensemble scale and open new
directions for neural interfaces to be used to detect and treat a variety of human brain disorders.
Suggested reading:
Hochberg LR, Bacher D, Jarosiewicz B, Masse NY, Simeral JD, Vogel J, Haddadin S, Liu J, Cash SS, van der Smagt P,
Donoghue JP. Reach and grasp by people with tetraplegia using a neurally controlled robotic arm. Nature. 2012 May
16;485(7398):372-5.
Bansal AK, Truccolo W, Vargas-Irwin CE, Donoghue JP. Decoding 3D reach and grasp from hybrid signals in motor and
premotor cortices: spikes, multiunit activity, and local field potentials. J Neurophysiol. 2012 Mar;107(5):1337-55.
Barrese JC, Rao N, Paroo K, Triebwasser C, Vargas-Irwin C, Franquemont L, Donoghue JP. Failure mode analysis of
silicon-based intracortical microelectrode arrays in non-human primates. J Neural Eng. 2013 Dec;10(6):066014
Simeral JD, Kim SP, Black MJ, Donoghue JP, Hochberg LR. Neural control of cursor trajectory and click by a human with
tetraplegia 1000 days after implant of an intracortical microelectrode array. J Neural Eng. 2011 Apr;8(2):025027.
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