The first test of an actual silicon device will soon be performed to help restore function to a slice of tissue from a rat’s damaged hippocampus!
This news item has been splashing into headlines all over the world yesterday and today, so we’re trying to keep track of the journalists’ take on the issue. As we keep finding more links, we’ll update this post.
Theodore Berger and his team at the University of Southern California have been working for years to develop mathematical models that represent the appropriate computations performed in the hippocampus of the brain, the area of your brain which is widely accepted as a major storage container and processor of memories. These models would then guide the design and fabrication of an actual silicon chip to be directly integrated with the brain tissue.
However, fully understanding the mechanisms of specific computations in our brain is still beyond scientists’ desperate grasp, so Berger’s team listened to neural activity and attempted to encode what they saw it into silicon.
To accomplish this, a silicon chip is fabricated with tiny electrodes–basically little metal pads and wires–that sit nearby active, non-damaged neurons and receive their electrical signals that are supposed to be providing “input” to damaged neurons. These captured input signals are transmitted by the embedded silicon chip to another chip sitting outside the brain. The external chip is like a mini-computer that processes these electrical signals according to Berger’s model of how the hippocampus is supposed to function. Based on this on-chip processing, it finally sends new electrical signals back down to the non-damaged neurons.
These computer-generated electrical signals are meant to exactly replace the electrical signals that would have resulted from the neurons receiving the original input, but couldn’t do so because they were damaged in some way.
Important note: This prototype brain prosthetic has been specifically programmed to function in a certain way–a way that neurons in a rat’s hippocampus presumably communicate. A successful test of this device will show that if the hippocampus is “turned off” in an animal and the device “turned on”, then normal brain activity resumes.
This would be a great step forward in developing technologies that replace damaged function in our nervous systems. Forgot where your keys are? Can’t find where you placed your presentation material due to your boss in exactly 1.2 minutes? No problem, just don’t forget to turn on your “memory chip”.
Maybe that’s where we are headed, but not by just copying our neural activity from when we were still healthy. One of the articles below mentions the concern that since what we consider to be our “self”, likely has a great deal to do with our memories, then a prosthetic device that has strict and static on-board processing rules, might somehow alter who we really “are”.
Certainly, more must be understood about how our brain functions in general, but this upcoming test is still very exciting!
[ Read the article from the New Scientist ]
[ Read the article from Ananova ]
[ Read the article from MSNBC.com ]
[ Read the article from BBC News ]
[ Read the article from the Guardian ]