Neurogrid
Encyclopedia
Neurogrid is a piece of computer hardware that is designed specifically for simulation of biological brains
. It uses analog computation
to emulate ion channel
activity, and digital communication to softwire structured connectivity patterns. Neurogrid simulates one million neuron
s and six billion synapse
s in real time. The neurons spike at a rate of ten times a second. This means it rivals simulations done by the Blue Brain Project
, but it uses one millionth of the 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
. The group is 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 a 11.9 mm x 13.9 mm chip. An off-chip RAM
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.
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. It uses analog computation
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
to emulate ion channel
Ion channel
Ion channels are pore-forming proteins that help establish and control the small voltage gradient across the plasma membrane of cells by allowing the flow of ions down their electrochemical gradient. They are present in the membranes that surround all biological cells...
activity, and digital communication to softwire structured connectivity patterns. Neurogrid simulates one million neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s and six billion synapse
Synapse
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell...
s in real time. The neurons spike at a rate of ten times a second. This means it rivals simulations done by the Blue Brain Project
Blue Brain
The Blue Brain Project is an attempt to create a synthetic brain by reverse-engineering the mammalian brain down to the molecular level.The aim of the project, founded in May 2005 by the Brain and Mind Institute of the École Polytechnique Fédérale de Lausanne is to study the brain's architectural...
, but it uses one millionth of the 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
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
. The group is 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 a 11.9 mm x 13.9 mm chip. An off-chip RAM
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...
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.