And still all slow stuff, 4 to 12 Hz. There must be something in the brain that clocks faster, but nobody seems to have found it yet.

It's way of my area of expertise, but my suspicion is that all these 4-12 Hz waves bouncing around in a 3D structure may be interfering to produce signals that tick much faster, and some functionality of the brain is clocked on that.

Seems to be pretty much in line with human reaction times?

I wouldn't be so sure that the brain necessarily clocks faster than that. I think it's more likely that faster chains of thought are defined by the flow of the wave rather than its frequency.