Efficiency/review paper to supplement bullmore presentation paper

[edunnwe1]

In class we kind of grappled a little bit with what global efficiency 'means' for brain graphs and using it as a metric. I think this review, which is co-authored by Bullmore, may offer a partial answer. http://www.nature.com.ezproxy.welch.jhmi.edu/nrn/journal/v10/n3/full/nrn2575.html. The idea seems to be that there is high information transfer relative to the 'cost' of many connections, considering almost an economic framework where one may have sparse 'resources' of neurons/synapses between neurons. In their conclusion they propose the hypothesis that there is a trade off between wiring cost and efficiency.

It seems that the idea emerges from statistical physics, and the reference they give for the emergence of that idea is: http://www.w3.org/People/Massimo/papers/2001/efficiency_prl_01.pdf (and http://www.w3.org/People/Massimo/papers/2003/efficiency_epjb_03.pdf)

Thoughts? The statistical analysis you could do on this measure still isn't clear to me.

[dlee138]

Interesting article. In the part of the article where the mention how age affects connections since younger adults had small-world properties over a broad range of connection densities while older brains showed this to a far lesser extent and had reduced cost efficiency - do they have any biological basis for this?

[SandyaS72]

So is "cost efficiency" a basically the ratio of speed of information transfer to cost of total connections?

[edunnwe1]

@SandyaS72 --yes, that's my understanding of it at least @dlee138 the reference for that particular point was ref #75, or the paper Achard, S. & Bullmore, E. T. Efficiency and cost of economical brain functional networks. PLoS Comput. Biol. 3, e17 (2007). (http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.0030017)