Neuro-evolutionary evidence for a universal fractal primate brain shape

Area of Science:

• Neuroscience
• Comparative Anatomy
• Mathematical Biology

Background:

• Cerebral cortex morphology exhibits significant diversity across species.
• Understanding the underlying principles of cortical folding remains a challenge.

Purpose of the Study:

• To present a universal multi-scale description of primate cortical shapes.
• To establish a common morphometric trajectory for mammalian cortices.
• To enable precise, scale-dependent quantification of brain morphology.

Main Methods:

• Analysis of cortical folding patterns in 11 primate species.
• Development of a scale-free morphometric model.
• Comparison with data from over 70 other mammalian species.

Main Results:

• All primate cortices approximate a single archetypal fractal shape (fractal dimension d = 2.5).
• Cortical shapes follow a common scale-free morphometric trajectory during fold merging.
• A scale-dependent effect of aging on brain morphology was identified, with increased effect size at ~2 mm scale.

Conclusions:

• Cerebral cortex shape is governed by universal fractal principles.
• This framework allows for more accurate quantification of brain morphology across scales.
• The findings may lead to improved biomarkers for neurological conditions.