Mine's Bigger: Connectivity Analysis Uses Sample Size of 439 Subjects



The next time you look at your dwindling scanning budget and realize you need to start coming in at 9:00pm on Fridays to pay a reduced scanning rate, just remember that there are other researchers out there who scan hundreds of subjects for a single study. (This isn't supposed to make you feel better; it's just a fact.)

A recent connectivity analysis by Dennis and colleagues recruited four hundred and thirty-nine subjects for a cross-sectional study to determine changes in connectivity from the ages of twelve to thirty. Overall, older participants showed decreasing long-range connectivity between regions, increased modularity (a measure of subdivision within regions), and hemispheric differences in global efficiency, consistent with developmental theories that short-range connections are pruned during adolescence while long-range connections are strengthened.

However, the observed hemispheric differences in global efficiency contrasted with previous findings:
Our results are contrary to those of Iturria-Medina et al. (2011), who found greater global efficiency in the right hemisphere, but these were from a relatively small sample of 11 subjects, and our sample is over 40 times larger. [Emphasis added.]

Boom. Over forty times larger, son. Sit the hell down. "But forty times eleven is four hundred forty." Yeah, well, the jury's still out on mathematics. "But we ran a well-controlled study!" WHAT PART OF FORTY TIMES LARGER DON'T YOU UNDERSTAND?!

Proof that size equals power can be found here.

Karl Friston's Rules for Reviewing

This post was orphaned a while back when I was testing links to papers, but I figured I should go back and explain what I was doing. This is a link to Friston's recent Neuroimage paper giving advice to young reviewers for how to reject any paper, regardless of how scientifically and statistically sound it is. His tone is purposely ironic, although he takes a more serious turn at the end in explaining why these rejection criteria are ridiculous.

The link to Friston's paper can be found here.