Skip to main content

Research Repository

Advanced Search

Human frontal lobes are not relatively large

Barton, R.A.; Venditti, C.

Authors

C. Venditti



Abstract

One of the most pervasive assumptions about human brain evolution is that it involved relative enlargement of the frontal lobes.We show that this assumption is without foundation. Analysis of five independent data sets using correctly scaled measures and phylogenetic methods reveals that the size of human frontal lobes, and of specific frontal regions, is as expected relative to the size of other brain structures. Recent claims for relative enlargement of human frontalwhite matter volume, and for relative enlargement shared by all great apes, seem to be mistaken. Furthermore, using a recently developed method for detecting shifts in evolutionary rates, we find that the rate of change in relative frontal cortex volume along the phylogenetic branch leading to humans was unremarkable and that other branches showed significantly faster rates of change. Although absolute and proportional frontal region size increased rapidly in humans, this change was tightly correlated with corresponding size increases in other areas andwhole brain size, and with decreases in frontal neuron densities. The search for the neural basis of human cognitive uniqueness should therefore focus less on the frontal lobes in isolation and more on distributed neural networks.

Citation

Barton, R., & Venditti, C. (2013). Human frontal lobes are not relatively large. Proceedings of the National Academy of Sciences, 110(22), 9001-9006. https://doi.org/10.1073/pnas.1215723110

Journal Article Type Article
Publication Date May 1, 2013
Deposit Date Apr 15, 2013
Journal Proceedings of the National Academy of Sciences
Print ISSN 0027-8424
Electronic ISSN 1091-6490
Publisher National Academy of Sciences
Peer Reviewed Peer Reviewed
Volume 110
Issue 22
Pages 9001-9006
DOI https://doi.org/10.1073/pnas.1215723110
Keywords Prefrontal cortex, Cognition, Primates.