Neurogrid is a piece of
computer hardware
Computer hardware includes the physical parts of a computer, such as the case, central processing unit (CPU), random access memory (RAM), monitor, mouse, keyboard, computer data storage, graphics card, sound card, speakers and motherboard.
...
that is designed specifically for
simulation of biological brains. It uses
analog computation
An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In c ...
to emulate
ion channel
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ...
activity, and digital communication to softwire structured connectivity patterns. Neurogrid simulates one million
neuron
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa ...
s and six billion
synapse
In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell.
Synapses are essential to the transmission of nervous impulses from ...
s in real time. The neurons spike at a rate of ten times a second. In terms of number of simulated neurons, it rivals simulations done by the
Blue Brain Project
The Blue Brain Project is a Swiss brain research initiative that aims to create a digital reconstruction of the mouse brain. The project was founded in May 2005 by the Brain and Mind Institute of ''École Polytechnique Fédérale de Lausanne'' (EP ...
. However, by running the simulation of whole neurons, instead of simulation on molecular level, it needs only one millionth of Blue Brain's power. The entire board consumes less than two watts of electrical energy.
Neurogrid was designed and built by the ''Brains in Silicon'' group at
Stanford University
Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is conside ...
. The group is led by
Kwabena Boahen
Kwabena Adu Boahen is a Professor of Bioengineering and Electrical Engineering at Stanford University. He previously taught at the University of Pennsylvania.
Education and early life
Kwabena Boahen was born on September 22, 1964, in Accra, Gha ...
. The Neurogrid hardware was first up and running in late 2009. Since then it has been used to start performing simulation experiments.
The Neurogrid board contains sixteen ''Neurocores'', each of which has 256 x 256 silicon neurons in an 11.9 mm x 13.9 mm chip. An off-chip
RAM
Ram, ram, or RAM may refer to:
Animals
* A male sheep
* Ram cichlid, a freshwater tropical fish
People
* Ram (given name)
* Ram (surname)
* Ram (director) (Ramsubramaniam), an Indian Tamil film director
* RAM (musician) (born 1974), Dutch
* ...
and an on-chip RAM (in each Neurocore) softwire horizontal and vertical cortical connections, respectively. With 61 graded and 18 binary programmable parameters, common to all of its silicon neurons, a Neurocore can model a variety of spiking and interaction patterns.
See also
*
CoDi
CoDi is a cellular automaton (CA) model for spiking neural networks (SNNs). CoDi is an acronym for Collect and Distribute, referring to the signals and spikes in a neural network.
CoDi uses a von Neumann neighborhood modified for a three-dime ...
References
External links
* {{homepage, http://www.stanford.edu/group/brainsinsilicon/neurogrid.html at Stanford University
Computational neuroscience
Simulation