A comment on brain activity

There is a good article in the March edition of Scientific American ("The Brain's Dark Energy" by Marcus E. Raichle) describing the emerging understanding that not only is the human brain always active, but that when it is not responding to immediate stimulus or managing physical action it must be doing important things. Otherwise why would it be expending almost as much energy when one is resting or asleep as it does during "activity". The researchers show that there are large areas of the brain that form what the author calls the Default Mode Network.

One thing that the author mentions is that research has shown that when Slow Cortical Potentials (which cycle relatively slowly in the brain) are on the rise there is an increase in signals at other potentials.

Back in the 1960s I was studying artificial neural networks. I wrote an article on time-varying threshold logic. I had recognized that one could increase the processing power of a neural network by providing a cycling input and recognizing not only that neurons fired in response to stimulus but when they fired during the cycle.

Of course the models of the 1960s were very simple, but they were useful in demonstrating the kinds of things that networks of simple elements could actually compute. It appears that the paper I wrote has disappeared from the conscious memory of the neuroscientists.