Neurogrid is a piece of
computer hardware
Computer hardware includes the physical parts of a computer, such as the central processing unit (CPU), random-access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices ...
that is designed specifically for
simulation of biological brains. It uses
analog computation 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 (electrophysiol ...
activity, and digital communication to softwire structured connectivity patterns. Neurogrid simulates one million
neuron
A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...
s and six billion
synapse
In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...
s in real time. The neurons spike at a rate of ten times a second. In terms of the total number of simulated neurons, it rivals simulations done by the
Blue Brain Project. 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
Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...
, led by
Kwabena Boahen. 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 most commonly refers to:
* A male sheep
* Random-access memory, computer memory
* Ram Trucks, US, since 2009
** List of vehicles named Dodge Ram, trucks and vans
** Ram Pickup, produced by Ram Trucks
Ram, ram, or RAM may also ref ...
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
References
External links
* {{homepage, http://www.stanford.edu/group/brainsinsilicon/, Brains in Silicon group at
Stanford University
Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...
Brains in Silicon: Neurogridpage (archived)
Computational neuroscience
Simulation