The Mind Chip
From: New Scientist - 02/03/2007 Vol. 193, No. 2589, P. 28
By: Douglas Fox

A notable achievement in computer vision has been made by researcher Kwabena
Boahen and colleagues at the University of Pennsylvania in Philadelphia, who
constructed a device that can see via chips that physically imitate the
electrical activity of neurons in the primary visual cortex. "I want to
figure out how the brain works in a very nuts-and-bolts way," explains
Boahen. "I want to figure it out such that I can build it." Boahen aims to
top his accomplishment of building an artificial retina with the creation of
an artificial cerebral cortex through the generalization of the chip's
function; such a breakthrough may be an important step in helping restore
neural function to people impaired by disease or injury. The concept of the
artificial neuron as a technology for enabling brain-like computing in real
time was first suggested in the late 1980s by California Institute of
Technology scientist Carver Mead, who discovered he could build such circuits
by having digital processors use transistors in their analog amplifier phase
instead of their on/off switching phase. Mounted on the surface of Boahen's
artificial retina are photosensitive transistors that translate incoming
light into analog voltages with a value determined by the light's intensity
and which last for as long as the light is beamed onto the transistors; these
transmissions are routed to the artificial retina neurons where motion and
regions of contrast are recognized, signaling the edges of objects in the
image. Processing information about edges and movement in the visual scene is
carried out by the low-power visual cortex chips, which build object outlines
out of the signals. A successful cortical implant will have to be able to
mimic the plasticity of the brain's neural network, in which connections
between neurons are created and adapted on the fly. 

Read the preview of this article at:
http://www.newscientisttech.com/channel/tech/mg19325891.500-the-mind-chip.html

Links:
Neuroengineering Research Laboratory of the University of Pennsylvania
http://www.neuroengineering.upenn.edu/

Kwabena Boahen, PhD
http://bioengineering.stanford.edu/faculty/boahen.html

Brains in Silicon
http://www.stanford.edu/group/brainsinsilicon/

Bioengineering professor hopes to mimic the brain on a chip
http://news-service.stanford.edu/news/2006/march22/boahensr-032206.html

A studied eye on the human brain
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/04/03/BUGOTI0US51.DTL

