The Adaptive Brain

In his terrific book, The Brain, David Eagleman writes:

“Your senses set boundaries on what you can experience… But what if the brain could understand new kinds of inputs?”

New inputs would come from accessories that we attach on or implant to our bodies. Yes, like a cyborg.

Whenever I’ve thought of this idea, I’ve felt the problem is that:

1)      We don’t yet understand how the brain works;

2)     And without knowing that, how would we know the “format” in which the input signals from the new sources/sensors/implants should be sent to the brain?

But it looks like there’s a way around that, by using this ability of the brain:

“(The brain) rewires itself to adjust to the inputs… It’s this property of the brain – its plasticity – that enables a new marriage between our technology and our biology.”

Ok, how far can that ability of the brain take us?

“Would the brain be able to understand crude, non-biological signals, or would it be confused by them?”

We’ve already tested this question! For deaf people, cochlear implants digitize sound signals and feed it to the auditory nerve. And for blind people, retinal implants digitize visual signals and feed it to the optic nerve at the back of the retina. Here’s how the brain learns to use those signals:

“At first the foreign electrical signals are unintelligible, but the neural networks eventually extract patterns from in incoming data… It hunts for patterns, cross-referencing with other senses. If there’s structure to be found in the incoming data, the brain ferrets it out – and after several weeks the information begins to take on meaning.”

The key point?

“I think of our sensory portals as peripheral plug-and-play devices. The key is that the brain doesn’t know and doesn’t care where it gets the data.”

So it looks like we don’t need to understand the brain entirely to make cyborgs a reality. The brain is already a general purpose device capable of learning to make sense of whatever inputs are thrown at it!