Vertex- and atlas-based comparisons in measures of cortical thickness, gyrification and white matter volume between humans and chimpanzees.
Level 4 - case-series / case-control
Cross-sectional comparative observational neuroimaging study
PubMed 27100220 · doi:10.1007/s00429-016-1213-1
What was done
MRI scans of human and chimpanzee brains were acquired on the same platform using identical imaging procedures. Cortical images were processed and segmented using FSL and FreeSurfer. The authors performed vertex- and atlas-based comparative analyses across the entire cortex to evaluate species differences in cortical thickness, gyrification, and regional white matter volume.
What was found
The abstract reports no exact numerical values, effect sizes, or test statistics. Directionally, relative to chimpanzees, human brains showed significantly greater gyrification, significantly thinner cortex (especially in the frontal lobe), and disproportionately higher white matter volumes in the frontal lobe, particularly in prefrontal regions.
Why it matters
This comparative neuroimaging study maps structural cortical differences between humans and chimpanzees, identifying frontal white matter expansion and gyrification as key neuroanatomical shifts following divergence from a common ancestor.
Limits
The abstract does not report the sample size (n), demographics (such as age or sex), or quantitative values and confidence intervals. Structural differences cannot directly establish causal mechanisms for cognitive or motor specializations.