Primate Prefrontal Cortex Evolution: Human Brains Are the Extreme of a Lateralized Ape Trend
Abstract
The prefrontal cortex is commonly associated with cognitive capacities related to human uniqueness: purposeful actions towards higher-level goals, complex social information processing, introspection, and language. Comparative investigations of the prefrontal cortex may thus shed more light on the neural underpinnings of what makes us human. Using histological data from 19 anthropoid primate species (6 apes including humans and 13 monkeys), we investigate cross-species relative size changes along the anterior (prefrontal) and posterior (motor) axes of the cytoarchitectonically defined frontal lobe in both hemispheres. Results reveal different scaling coefficients in the left versus right prefrontal hemisphere, suggest that the primary factor underlying the evolution of primate brain architecture is left hemispheric prefrontal hyperscaling, and indicate that humans are the extreme of a left prefrontal ape specialization in relative white to grey matter volume. These results demonstrate a neural adaptive shift distinguishing the ape from the monkey radiation possibly related to a cognitive grade shift between (great) apes and other primates.
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Mosaic studies have mainly focused on allometric scaling trends of particular brain structures.
“Mosaic studies have mainly focused on allometric scaling trends of particular brain structures [4,17].”
From Brain reorganization, not relative brain size, primarily characterizes anthropoid brain evolution (2013) · cites this paper as [17]
Comparative data on brain structures that are fundamental to neural processing (prefrontal cortex, frontal motor areas and cerebellar lobules) have not been available until very recently, hampering more in-depth insights on the systemic nature of mosaic brain evolution.
“comparative data on brain structures that are fundamental to neural processing (prefrontal cortex, frontal motor areas and cerebellar lobules) have not been available until very recently [11,17,19–21], hampering more in-depth insights on the systemic nature of mosaic brain evolution.”
From Brain reorganization, not relative brain size, primarily characterizes anthropoid brain evolution (2013) · cites this paper as [17]
Recent allometric analyses reveal that, although absolute and proportional frontal region size increased rapidly in hominins, this change was associated with size increase in other areas and whole brain size, rather than with specialization for enlarged frontal lobes specifically.
“Recent allometric analyses reveal that, although absolute and proportional frontal region size increased rapidly in hominins, this change was associated with size increase in other areas and whole brain size, rather than with specialization for enlarged frontal lobes specifically [57,61–63].”
From Embodied cognitive evolution and the cerebellum (2012) · cites this paper as [57]
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Self-citation
- Authors
- Smaers, J. B., Steele, J., Case, C. R., Cowper, A., Amunts, K., & Zilles, K.
- Affiliations
- Arts and Humanities Research Council (GB)
- Universitätsklinikum Aachen (DE)
- Forschungszentrum Jülich (DE)
- Venue
- Brain, Behavior and Evolution
- Publisher
- S. Karger AG
- Published
- 2011
- Volume
- 77
- Issue
- 2
- Pages
- 67-78
- ISSN
- 0006-8977 (ISSN-L)
- 1421-9743
- OpenAlex
- W2022686960
- Cited by
- 160
- References
- 67
- Citations by year
- 2026: 1 · 2025: 5 · 2024: 30 · 2023: 11 · 2022: 8 · 2021: 6 · 2020: 10 · 2019: 6 · 2018: 7 · 2017: 7 · 2016: 14 · 2015: 8 · 2014: 11 · 2013: 17 · 2012: 11
- FWCI
- 20.08
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Brain Behavior and Evolution (publishedVersion)
- PubMed (publishedVersion)
- UCL Discovery (University College London) (submittedVersion)
- JuSER (Forschungszentrum Jülich) (submittedVersion)
- RWTH Publications (RWTH Aachen) (submittedVersion)
- Funders
- National Science Foundation (0923791)
- Johns Hopkins University
- Topics
- Social Sciences › Psychology › Social Psychology › Primate Behavior and Ecology
- Life Sciences › Neuroscience › Cognitive Neuroscience › Hemispheric Asymmetry in Neuroscience
- Life Sciences › Neuroscience › Cognitive Neuroscience › Neural and Behavioral Psychology Studies
- Keywords
- prefrontal cortex, primate brain evolution, hemispheric lateralization, anthropoid primates, great apes, monkeys, frontal lobe, brain size scaling, cognitive evolution, human uniqueness
- MeSH terms
- Animals, Biological Evolution, Humans, Functional Laterality, Male, Hominidae, Prefrontal Cortex
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