Study maps five life stages of brain wiring
Neuroscientists at the University of Cambridge report in Nature Communications that the human brain passes through five structural 'epochs' from birth to age 90, with key turning points around ages 9 and 32 and a long stable adult phase before aging-related reorganization after 66. Using diffusion MRI in 3,802 individuals, the team found adolescence-like structural changes persist into the early 30s, adulthood stabilizes roughly from 32 to 66, and early aging shows reduced connectivity and white-matter degeneration.
📌 Key Facts
- Sample: 3,802 participants from birth to 90 years old
- Method: diffusion MRI mapping water movement; tractography of brain networks
- Turning points: around ages 9 (childhood to adolescence) and 32 (adolescence to adulthood); stability from ~32–66; reorganization after ~66
📊 Relevant Data
The amygdala-PFC neural system reaches maturity earlier in females than in males.
Sex differences in maturational timing of amygdala and prefrontal connectivity — Developmental Cognitive Neuroscience
Black children show lower amygdala, hippocampus, and PFC gray matter volumes compared to White children.
Disparities Linked to Differences in Brain Structures in U.S. Children — Harvard Medical School
Black adults show an accelerated pattern of brain aging beginning in midlife compared to Latinx and White adults.
Brain Aging Among Racially and Ethnically Diverse Middle-Aged and Older Adults — NIH (PMC)
Genetic ancestry explains approximately 60% of the differences in gene expression in brain samples from Black individuals.
📊 Analysis & Commentary (1)
"The piece argues that Oliver Sacks functioned more as a popularizer and narrative clinician than as a modern empirical neuroscientist, contrasting his anecdotal, case‑based method with recent large‑scale brain‑wiring studies and warning against conflating storytelling with generalizable science."