Robert Kurzban, a University of Pennsylvania psychologist, says his re-analysis of a 2007 study finds the claim the brain is depleted of extra glucose when exerting self-control is contradicted by the study's own data.
The re-analysis, published in Evolutionary Psychology, finds the prior research did not show glucose levels decreased among subjects performing self-control tasks.
"For this model to be correct, it obviously must be the case that performing a self-control task reduces glucose levels relative to pre-task levels," Kurzban says in a statement.
In other words, Kurzban says, his re-analysis shows the researchers' own data undermine the model they advance.
"Even very different computational tasks result in very similar glucose consumption by the brain, which tends to metabolize glucose at similar rates independent of task," Kurzban says.