We like to think of the human brain as special, but as we reported on Plus last year, it has quite a lot in common with worm brains and even with high-performance information processing systems. But how does it compare to online social networks? In a recent lecture the psychiatrist Ed Bullmore put this question to the test.

The human brain faces a difficult trade-off. On the one hand it needs to be complex to ensure high performance, and on the other it needs to minimise "wiring cost" — the sum of the length of all the connections — because communication over distance takes a lot of energy. It's a problem well-known to computer scientists. And it seems that market driven human invention and natural selection have come up with similar solutions.