From what I understand though, that's exactly why Johnson invested his own money and turned down outside investment: this is just the first step on a very long road, and it doesn't sound like he anticipates a viable return in an amount of time that a venture fund could justify participating in.

>" The futuristic device, which Johnson says might actually not need to be implanted beneath the skull at all, is designed to facilitate communication between brain cells by hacking the “neural code” that enables our brain to store and recall key information. "

Estimated timescale: centuries. Not for want of trying, but we have no credible idea what "the" neural code is, even in subcortical areas that are relatively simple to study like the optic and auditory nerves. Once you're anywhere beyond the inferior colliculus, all bets are officially off. (and if you have any good ideas, drop me a line!)

Our best tools fail to explain anything particularly interesting about much, much simpler analogous systems: http://biorxiv.org/content/early/2016/05/26/055624.